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CHEMISTRY, M4 EQ-Bank 3

A 3.1g sample of decomposes into and . Entropy values  for these chemicals are given below and the molar enthalpy for the reaction is 360 kJ/mol.

  1. Write a chemical equation for the above reaction.  (1 mark)

  2. Calculate the entropy change for this reaction.  (2 marks)

  3. Determine whether the reaction is spontaneous or non-spontaneous at room temperature.  (2 marks)

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i.   

ii.      
   
   

 


 

iii.   

 
   
   

 

CHEMISTRY, M4 EQ-Bank 2

In the following reactions, predict whether entropy will increase or decrease, giving reasons. (3 marks)

  1.    (1 mark)
  2.    (1 mark)
  3.    (1 mark)
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i.     → Decrease

→ 4 moles of gas becomes 2 moles of gas on the product side, causing the reaction to become more ordered and decreasing in entropy.

ii.    → Increase

→ A solid decomposes into 2 moles of gas. This reaction becomes more disordered, and the phase change involves an increase in entropy.

iii.   → Increase

→ An aqueous and solid reactant becomes an aqueous and gaseous product. The phase changes overall involve an increase in entropy.

Show Worked Solution

i.     → Decrease

→ 4 moles of gas becomes 2 moles of gas on the product side, causing the reaction to become more ordered and decreasing in entropy.
 

ii.    → Increase

→ A solid decomposes into 2 moles of gas. This reaction becomes more disordered, and the phase change involves an increase in entropy.
 

iii.   → Increase

→ An aqueous and solid reactant becomes an aqueous and gaseous product. The phase changes overall involve an increase in entropy.

CHEMISTRY, M3 2013 VCE 14-15 MC


 

Which one of the following will not increase the rate of the above reaction?

  1. decreasing the size of the solid copper particles
  2. increasing the temperature of  by 20 °C
  3. increasing the concentration of
  4. allowing  gas to escape

 

In the above reaction, the number of successful collisions per second is a small fraction of the total number of collisions.

The major reason for this is that

  1. the nitric acid is ionised in solution.
  2. some reactant particles have too much kinetic energy.
  3. the kinetic energy of the particles is reduced when they collide with the container’s walls.
  4. not all reactant particles have the minimum kinetic energy required to initiate the reaction.
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→ Options and will all increase the rate of the given chemical reaction.


 

→ Successful collisions occur only if the particles involved have at least the minimum kinetic energy required and the correct orientation.

CHEMISTRY, M2 2012 16*

A helium balloon is inflated to a volume of 5.65 L and a pressure of 10.2 atm at a temperature of 25°C.

Calculate the amount of helium, in moles, in the balloon.   (2 marks)

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PHYSICS, M4 2019 VCE 6a

A home owner on a large property creates a backyard entertainment area. The entertainment area has a low-voltage lighting system. To operate correctly, the lighting system requires a voltage of 12 . The lighting system has a resistance of 12 .

Calculate the power drawn by the lighting system.  (3 mark)

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→ Using  and 

 
   
   

→ The power drawn from the lighting system is 12 .

PHYSICS, M4 2019 VCE 2

Figure 2 shows two equal positive stationary point charges placed near each other.

 

 
 

 

Sketch on Figure 2 the shape and direction of the electric field lines. Use at least eight field lines.  (2 marks) 

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→ Field lines must not touch.

→ Fields will repel one another.

CHEMISTRY, M2 2014 VCE 9*

An aerosol can with a volume of 300.0 mL contains 2.80 g of propane gas as a propellant. The warning label says the aerosol may explode at temperatures above 60.0 °C.

What is the pressure in the can at a temperature of 60.0 °C?   (2 marks)

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CHEMISTRY M2 2015 VCE 2*

When concentrated sulfuric acid is added to dry sucrose, , a black residue of pure carbon is produced.

An equation for the reaction is

Calculate the mass of carbon residue that could be produced by the reaction of 50.0 g of sucrose with excess concentrated sulfuric acid.   (2 marks) 

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PHYSICS, M3 2020 VCE 13

A 0.8 m long guitar string is set vibrating at a frequency of 250 Hz. The standing wave envelope created in the guitar string is shown in Figure 12.
 

  1. Calculate the speed of the wave in the guitar string.  (2 marks)

  2. The frequency of the vibration in the guitar string is tripled to 750 Hz.
  3. On the guitar string below, draw the shape of the standing wave envelope now created. (2 marks)

 

 

 

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a.   

b. 
       

Show Worked Solution
a.     
   
   

  
b.
         

→ Tripling the frequency means decreasing the wavelength by a factor of 3, hence three half wavelengths will now fit on the string.

PHYSICS, M4 2020 VCE 1

Two bar magnets are placed close to each other, as shown in Figure 1.

Sketch the shape and the direction of at least four magnetic field lines between the two poles within the dashed border shown in Figure 1.  (2 marks)
 

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PHYSICS, M2 2020 VCE 9-10 MC

Two blocks of mass 5 kg and 10 kg are placed in contact on a frictionless horizontal surface, as shown in the diagram below. A constant horizontal force, , is applied to the 5 kg block.
 
 


 

Which one of the following statements is correct?

  1. The net force on each block is the same.
  2. The acceleration experienced by the 5 kg block is twice the acceleration experienced by the 10 kg block.
  3. The magnitude of the net force on the 5 kg block is half the magnitude of the net force on the 10 kg block.
  4. The magnitude of the net force on the 5 kg block is twice the magnitude of the net force on the 10 kg block.

 

If the force has a magnitude of 250 N, what is the work done by the force in moving the blocks in a straight line for a distance of 20 m?

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Using Newton’s second Law:  .

→ The blocks will experience the same acceleration.

→ Both blocks will have the same force to mass ratio. Since the 5 kg block is half the mass of the 10 kg block, it will experience half the magnitude of the net force as the 10 kg block.

♦ Mean mark 49%.

 

 
   
   
   

 

PHYSICS, M3 2021 VCE 14

A distant fire truck travelling at 20 ms to a fire has its siren emitting sound at a constant frequency of 500 Hz.

Chris is standing on the edge of the road. Assume that the fire truck is travelling directly towards him as it approaches and directly away from him as it goes past. The arrangement is shown in Figure 14.
 

  1. On the diagram below, sketch the frequency that Chris will hear as the truck moves towards him and then moves away from him. The siren signal is shown as a dotted line for reference. No calculations are required.  (2 marks)
     


 

  1. Name the physics principle involved in Chris’s experience.  (1 mark)
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a.    

  
b.   The Doppler effect
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a.    

♦♦♦ Mean mark (a) 13%.
COMMENT: Poorly completed by most students, many incorrectly drew a smooth line that passed Chris at 500 Hz.
  
b.   The Doppler effect

PHYSICS, M3 2022 VCE 16

A small sodium lamp, emitting light of wavelength 589 nm, is viewed at night through two windows from across a street. The glass of one window has a fine steel mesh covering it and the other window is open, as shown in Figure 18. Assume that the sodium lamp is a point source at a distance.

A Physics student is surprised to see a pattern formed by the light passing through the steel mesh but no pattern for the light passing through the open window. She takes a photograph of the observed pattern to show her teacher, who assures her that it is a diffraction pattern.
 

  1. State the condition that the fine steel mesh must satisfy for a diffraction pattern to form.  (1 mark)
  1. Explain why the condition stated in part a. does not apply to the open window.  (2 marks)
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a.   Condition to satisfy:

→ The size of the gaps from the fine steel mesh must be of the same order of magnitude of the wavelengths of the light from the sodium lamp.

b.   Open window differences:

→ The width of the window is significantly greater than wavelength of the light from the sodium lamp and the width of the glass molecules that make up the glass window is significantly smaller than the light from the sodium lamp.

→ These widths contrast greatly to the size of the steel mesh and are not of the same order of magnitude of the light from the sodium lamp, hence no diffraction will occur.

Show Worked Solution

a.   Condition to satisfy:

→ The size of the gaps from the fine steel mesh must be of the same order of magnitude of the wavelengths of the light from the sodium lamp.


b.   Open window differences:

→ The width of the window is significantly greater than wavelength of the light from the sodium lamp and the width of the glass molecules that make up the glass window is significantly smaller than the light from the sodium lamp.

→ These widths contrast greatly to the size of the steel mesh and are not of the same order of magnitude of the light from the sodium lamp, hence no diffraction will occur.

♦ Mean mark (b) 40%.

PHYSICS, M2 2022 VCE 7

Kym and Kelly are experimenting with trolleys on a ramp inclined at 25°, as shown in Figure 7. They release a trolley with a mass of 2.0 kg from the top of the ramp. The trolley moves down the ramp, through two light gates and onto a horizontal, frictionless surface. Kym and Kelly calculate the acceleration of the trolley to be 3.2 m s using the information from the light gates.
 
 

  1.  i. Show that the component of the gravitational force of the trolley down the slope is . Use .  (2 marks)
  1. ii. Assume that on the ramp there is a constant frictional force acting on the trolley and opposing its motion.
  2.      Calculate the magnitude of the constant frictional force acting on the trolley.  (2 marks)
  1. When it reaches the bottom of the ramp, the trolley travels along the horizontal, frictionless surface at a speed of 4.0 m s until it collides with a stationary identical trolley. The two trolleys stick together and continue in the same direction as the first trolley.
    1. Calculate the speed of the two trolleys after the collision. Show your working and clearly state the physics principle that you have used.  (3 marks)
    1. Determine, with calculations, whether this collision is an elastic or inelastic collision. Show your working.  (3 marks)
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a.i.   See Worked Solutions

a.ii. 

b.i.   

 b.ii.  For the collision to be elastic, the kinetic energy must be conserved.

→ As the kinetic energy of the system decreases after the collision, it is not an elastic collision.

Show Worked Solution

a.i.  The gravitational force down the slope:

 
   
     

 

a.ii.   
   
   

 

 
 
   
♦ Mean mark (a.ii) 53%.

 
b.i.   By the conservation of momentum:

 
 
 
 
 

 b.ii.  For the collision to be elastic, the kinetic energy must be conserved.

→ As the kinetic energy of the system decreases after the collision, it is not an elastic collision.

PHYSICS, M3 2022 VCE 11 MC

Which one of the following statements best describes transverse and longitudinal waves?

  1. Both transverse waves and longitudinal waves travel in a direction parallel to their vibrations.
  2. Both transverse waves and longitudinal waves travel in a direction perpendicular to their vibrations.
  3. Transverse waves travel in a direction perpendicular to their vibrations; longitudinal waves travel parallel to their vibrations.
  4. Transverse waves travel in a direction parallel to their vibrations; longitudinal waves travel perpendicular to their vibrations.
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Show Worked Solution

→ The energy transfer through transverse waves is perpendicular to the direction of vibrations.

→ The energy transfer through longitudinal waves is parallel to the direction of vibrations.
 

PHYSICS, M3 2022 VCE 10 MC

Which one of the following statements best describes an observation of the Doppler effect for sound?

  1. a decrease in frequency received when a source of sound moves towards you
  2. a decrease in frequency received when moving towards a stationary source of sound
  3. an increase in frequency received when moving towards a stationary source of sound
  4. a decrease in wavelength received when moving away from a stationary source of sound
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Show Worked Solution

→ As a result of the Doppler effect, when there is relative movement towards a source of sound waves the frequency of the observed sound waves is increased.

PHYSICS, M2 2022 VCE 6-7 MC

A railway truck of mass 10 tonnes, moving at 3.0 m s, collides with a stationary railway truck , as shown in the diagram below.

After the collision, they are joined together and move off at speed  .
 


 

Which one of the following is closest to the mass of railway truck ?

  1. 3 tonnes
  2. 5 tonnes
  3. 6.7 tonnes
  4. 15 tonnes

 

Which one of the following best describes the force exerted by the railway truck on the railway truck and the force exerted by the railway truck on the railway truck at the instant of collision?

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→ By the law of conservation of momentum, the momentum before the collision is equal to the momentum after the collision.

 
   
 
 
   
     

 

→ By Newton’s 3rd law of motion, each action has an equal and opposite reaction. 

→ Hence, the force of is equal in magnitude to but opposite in direction which is indicated by the negative sign (–).

♦ Mean mark (Q7) 47%.

BIOLOGY, M3 2022 VCE 32-33 MC

Victoria’s fossil emblem Koolasuchus cleelandi, shown on the stamp above, was chosen in January 2022.

K. cleelandi fossils have been found in Boonwurrung country in Gippsland. Studies of K. cleelandi fossils have revealed many interesting findings. Several of these findings are summarised below.

K. cleelandi findings

    1. It was an amphibian that lived 125 million years ago.
    2. It had a jaw, a skull, vertebrae and ribs made of bone.
    3. It was covered in scales and had fangs on the roof of its mouth.
    4. It lived in rivers carrying many sediments.
    5. It lived in Victoria for 50 million years after its closest relatives in the rest of the world became extinct.
    6. It fed on small dinosaurs, turtles and fish.
    7. It was the size of a small car, 4 m long and weighed 500 kg.
       

Part 1

Which combination of findings from the list above is most likely to be associated with an increased chance of formation of K. cleelandi fossils?

  1. findings 1 and 6
  2. findings 2 and 4
  3. findings 3 and 5
  4. findings 2 and 7

 
Part 2

It is most likely that scientists determined the absolute age of K. cleelandi fossils

  1. through mtDNA analysis of K. cleelandi scales and fangs.
  2. through carbon-14 dating of jaw bones, skull, vertebrae and ribs.
  3. by finding index fossils nearby, such as those of small dinosaurs and turtles.
  4. through radioisotope dating of rock surrounding the fossils.
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→ K. cleelandi has large, dense bones (finding 2) which are less likely to decay overtime and hence have a higher chnace of being fossilised for a long period of time.

→ Because these bones are remaining in a river carrying many sediments (finding 4) the bones are more likely to be fossilised as they are covered quicker, reducing disturbance and hiding them from scavnegers.


  

→ Radioisotope dating of rocks is extremely accurate and reliable source of dating. Therefore it ios likely that scientists dated K. cleelandi fossils by dating the surrounding rock.

♦ Mean mark (part 2) 52%.

BIOLOGY, M1 2022 VCE 19 MC

Enzymes are associated with the biochemical pathways of cellular respiration and photosynthesis.

Consider a cell that carries out both cellular respiration and photosynthesis.

Which one of the following is a correct statement about the enzymes associated with these pathways?

  1. Both pathways are catalysed by the same enzymes.
  2. An increase in pH above the optimal pH for cellular respiration may cause the enzymes to denature.
  3. The rates of these biochemical pathway reactions are not affected by changes in the concentrations of the enzymes.
  4. A drastic increase in temperature above the optimal temperature for photosynthesis will cause an increase in the rate of photosynthesis.
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Show Worked Solution

By Elimination

→ While the net chemical equations for photosynthesis and cellular respiration appear to be the reverse of each other, each reaction is made up of various processes which require different reaction conditions, including different enzymes (Eliminate A).

→ Enzyme concentrations can increase/decrease the amount of available active sites which can change the rate of reaction rate (Eliminate C).

→ A large increase in temperature would not increase reaction rate but would denature the enzymes (Eliminate D).

→ Changes in various factors, including pH, can denature an enzyme if the change is outside the optimal range for that factor.

CHEMISTRY, M4 2014 VCE 1

The decomposition of ammonia is represented by the following equation.

  1. The activation energy for the uncatalysed reaction is 335 kJ mol.
  2. The activation energy for the reaction when tungsten is used as a catalyst is 163 kJ mol.
  3. On the grid provided below, draw a labelled energy profile diagram for the uncatalysed and catalysed reactions.  (3 marks)
     

  1. When osmium is used as a catalyst, the activation energy is 197 kJ mol.
  2. Which catalyst – osmium or tungsten – will cause ammonia to decompose at a faster rate? Justify your answer in terms of the chemical principles you have studied this year.  (2 marks)

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a.    

 

b.    → Tungsten will cause ammonia to decompose faster.

→ Faster rate due to lower activation energy.

→ Lower activation energy results in a greater proportion of successful collisions.

Show Worked Solution

a.    

     

b.   → Tungsten will cause ammonia to decompose faster.

→ Faster rate due to lower activation energy.

→ Lower activation energy results in a greater proportion of successful collisions.

CHEMISTRY, M4 2018 VCE 13 MC

The energy profile diagram below represents a particular reaction. One graph represents the uncatalysed reaction and
the other graph represents the catalysed reaction.
 

Which of the following best matches the energy profile diagram?
 

 



A.  
B.
C.
D.
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Show Worked Solution

→ The of the uncatalysed reaction is higher (90) than the catalysed reaction (40).

→ The energy changes are based off the zero reading (pre-reaction) to the final energy. 

CHEMISTRY, M4 2017 VCE 29 MC

The following energy profile shows the results obtained during an enzyme-catalysed reaction. Each stage of the reaction is labelled: M represents the initial reactants, N represents a stable intermediate and P represents the final products.
 

Which one of the following statements is correct?

  1. The energy change from M to N is exothermic and the energy change from N to P is exothermic.
  2. The energy change from M to P is exothermic and the energy change from N to P is endothermic.
  3. The energy change from M to N is endothermic and the energy change from N to P is endothermic.
  4. The energy change from M to N is endothermic and the energy change from M to P is endothermic.
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Show Worked Solution

is endothermic since energy of products > energy of reactants.

is endothermic

is exothermic

CHEMISTRY, M4 2005 HSC 17

  1. The heat of combustion of ethanol is 1367 kJ mol. In a first-hand investigation to determine the heat of combustion of ethanol, the experimental value differed from the theoretical value.
  2. Identify a reason for this difference.   (1 mark)

  3. Calculate the theoretical mass of ethanol required to heat 200 mL of water from 21.0°C to 45.0°C.   (2 marks)
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a.    Answers could include one of the following:

→ Heat loss into the surroundings from combustion process.

→ Specific examples of heat loss such as inefficient heating of water caused by proximity of the heat or not using a beaker lid.

b.   

Show Worked Solution

a.    Answers could include one of the following:

→ Heat loss into the surroundings from combustion process.

→ Specific examples of heat loss such as inefficient heating of water caused by proximity of the heat or not using a beaker lid.
 

b.   

CHEMISTRY, M4 EQ-Bank 10 MC

Which statement explains why catalysts are often used in chemical reactions?

  1. Catalysts increase the activation energies of reactions.
  2. Catalysts increase the rate of reactions.
  3. Catalysts increase the yield of products of reactions.
  4. Catalysts increase the purity of products of reactions.
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Show Worked Solution

→ Catalysts increase the rate of reactions.

CHEMISTRY, M3 2018 VCE 2

Hydrogen peroxide, , in aqueous solution at room temperature decomposes slowly and irreversibly to form water, , and oxygen, , according to the following equation.

   

  1. What effect will increasing the temperature have on the rate of production? Use collision theory to explain your answer.  (3 marks)

  2. When a small lump of manganese() dioxide, , is added to the solution, the rate of production increases, but when powdered is added instead, the rate of production is greatly increased. The is recovered at the end of the reaction.
  3. State the function of in this reaction.  (1 mark)

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a.    → Increasing the temperature will increase the rate of production.

→ An increase in temperature increases the kinetic energy of all molecules which causes both the frequency of collisions and the energy of each collision to increase.

→ The temperature increase results in more collisions, of which a higher proportion are successful (i.e. occur with greater energy than the activation energy threshold required to react).
 

b.    acts as a catalyst in this reaction.

Show Worked Solution

a.    → Increasing the temperature will increase the rate of production.

→ An increase in temperature increases the kinetic energy of all molecules which causes both the frequency of collisions and the energy of each collision to increase.

→ The temperature increase results in more collisions, of which a higher proportion are successful (i.e. occur with greater energy than the activation energy threshold required to react).
 

b.    acts as a catalyst in this reaction.

CHEMISTRY, M2 2020 VCE 6a*

Methane gas, , can be captured from the breakdown of waste in landfills. is also a primary component of natural gas. can be used to produce energy through combustion.

Write the balanced equation for the complete combustion of to produce carbon dioxide, given the unbalanced equation below.  (1 mark)

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Show Worked Solution

CHEMISTRY, M2 2018 VCE 10 MC

Bioethanol, , is produced by the fermentation of glucose, , according to the following equation.

The mass of obtained when 5.68 g of carbon dioxide, , is produced is

  1. 0.168 g
  2. 0.337 g
  3. 2.97 g
  4. 5.94 g
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PHYSICS, M1 2012 HSC 21

  1. Outline a first-hand investigation that could be performed to measure a value for acceleration due to gravity.   (3 marks)

  2. How would you assess the accuracy of the result of the investigation?   (1 mark)

  3. How would you increase the reliability of the data collected?   (1 mark)

  4. How would you assess the reliability of the data collected?   (1 mark)

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a.    Timing of a falling mass.

→ Set up an electronic and automatic timing system with sensors to detect the presence of a small falling metal ball.

→ Heights for the ball should be set up between 0.2 m to 1 m with intervals every 0.2 m. To increase the reliability of the results, multiple trials should be conducted at each height and the average falling time for each height should be calculated which can then be used to graph the data.

→ The results should be plotted on a graph of height vs time. This uses the equation    where    which becomes  .

→ After plotting the data, the acceleration due to gravity, , can be calculated using  , which will make it equal to 2 × the gradient of the line of best fit.
 

b.    → Look up known value on a reliable website (e.g. National Measurement Institute).

→ Ensure the value is for the location of the experiment (it can differ slightly).

→ Compare the known value to the value determined experimentally and the closer they are, the greater the accuracy of the experiment.
 

c.    → Conduct multiple trials at each height.

→ Use the average of the calculations as stated in the method above.
 

d.   → Compare the values obtained at a single height.

→ If there is a large variation in the calculations conducted at the same height, the data collected is less reliable.

Show Worked Solution

a.    Timing of a falling mass.

→ Set up an electronic and automatic timing system with sensors to detect the presence of a small falling metal ball.

→ Heights for the ball should be set up between 0.2 m to 1 m with intervals every 0.2 m. To increase the reliability of the results, multiple trials should be conducted at each height and the average falling time for each height should be calculated which can then be used to graph the data.

→ The results should be plotted on a graph of height vs time. This uses the equation    where    which becomes  .

→ After plotting the data, the acceleration due to gravity, , can be calculated using  , which will make it equal to 2 × the gradient of the line of best fit.

♦ Mean mark (a) 55%.

b.    → Look up known value on a reliable website (e.g. National Measurement Institute).

→ Ensure the value is for the location of the experiment (it can differ slightly).

→ Compare the known value to the value determined experimentally and the closer they are, the greater the accuracy of the experiment.

♦♦♦ Mean mark (b) 26%.

c.    → Conduct multiple trials at each height.

→ Use the average of the calculations as stated in the method above.

 
d.   → Compare the values obtained at a single height.

→ If there is a large variation in the calculations conducted at the same height, the data collected is less reliable.

♦♦♦ Mean mark (d) 7%.

PHYSICS, M4 2012 HSC 6 MC

The diagram represents the electric field around a negative charge.
 

   

If the magnitude of the charge were doubled, which diagram would best represent the new electric field?

 


 

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Show Worked Solution

→ The density of the field lines corresponds to the strength of the electric field surrounding the point charge.

→ Hence a stronger charge produces a stronger field and so the field lines become denser.

CHEMISTRY, M5 2023 HSC 12 MC

The industrial production of ammonia is represented by the Haber process reaction shown.

Factors such as temperature and pressure need to be considered in order to maximise yield.

Which of the following is correct?

  1. A lower pressure would result in a higher yield.
  2. A higher pressure would result in a higher yield.
  3. A lower temperature would result in a lower yield.
  4. A higher temperature would result in a higher yield.
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Show Worked Solution

→ Increasing the pressure would shift the position of equilibrium to the side of the equation with less moles (as per Le Chatelier’s principle).

→ This would increase the yield of

CHEMISTRY, M5 2023 HSC 4 MC

Sodium chloride dissolves in water according to the following equation.

A saturated solution of in water contains sodium and chloride ions at the following concentrations.
 

  
  
What is the of sodium chloride?
 
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Show Worked Solution

 
   

 

CHEMISTRY, M7 2023 HSC 3 MC

The structural formula of a compound is given.
 

What is the preferred IUPAC name of this compound?

  1. Pent-2-ene
  2. Pent-2-yne
  3. Pent-3-ene
  4. Pent-3-yne
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Show Worked Solution

→ The organic molecule has a 5-Carbon backbone, therefore the prefix will be “Pent”

→ The molecule contains no branches, so the rest of its name will be defined by the triple carbon bond “yne”

→ The rules of nomenclature state that the name must assign the triple carbon bond the lowest carbon number, this is achieved by numbering the carbons from right to left, placing the triple carbon bond at carbon 2

→ Hence the name of the compound is “Pent-2-yne”

PHYSICS, M1 2013 HSC 4 MC

Students performed an investigation to determine the initial velocity of a projectile.

Which row correctly identifies a hazard of this investigation and a related precaution?
 

  Hazard Safety precaution
A.   flying projectile wearing safety glasses
B.  range of projectile measuring the range with a tape measure
C.  enclosed shoes limiting the range of the projectile
D.  safety glasses flying projectile
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Show Worked Solution

→ A hazard is a danger and the only danger in the answer options is the flying projectile.

→ Wearing safety glasses will protect students eyes from being hit from the projectile.

PHYSICS, M4 2015 HSC 24b

A part of a cathode ray oscilloscope was represented on a website as shown.
 

Electrons leave the cathode and are accelerated towards the anode.

Calculate the force on an electron due to the electric field between the cathode and the anode.   (2 marks)

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N

Show Worked Solution

Using  and  :

 
   
  N  

PHYSICS, M4 2015 HSC 5 MC

Why does the electrical resistance of a metal increase as temperature increases?

  1. Lattice vibrations increase, scattering more electrons.
  2. Electrons pair up, increasing their interactions with the crystal lattice.
  3. Fewer electrons are free to move, as they fill the holes in the conduction band.
  4. Electrons move more freely through the metal, unimpeded by the crystal lattice.
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Show Worked Solution

→ As the temperature of a metal increases, the average kinetic energy of the atoms in the lattice that make up the metal increases.

→ This causes the lattice to vibrate.

→ The vibrating lattice then interferes with the flow of electrons through the metal leading to a greater electrical resistance.

Proof, EXT2 P1 2023 HSC 4 MC

Consider the following statement about real numbers.

"Whichever positive number you pick, it is possible to find a number greater than 1 such that

. "

When this statement is written in the formal language of proof, which of the following is obtained?

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Show Worked Solution

PHYSICS, M4 2017 HSC 3 MC

Which of the following correctly shows the electric field between two parallel, charged plates?
 


 

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Show Worked Solution

→ The electric field lines are defined by the direction of force on a positive charge.

→ A positive charge will experience a repulsive force from the positive plate and attractive force to the negative plate.

CHEMISTRY, M7 2023 HSC 21

Some isomers with the formula are shown.
 

Name ONE pair of functional group isomers and ONE pair of chain isomers from the structures above.  (2 marks)

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Functional Group: Butan-2-one and butanal

Chain: Butanal and 2-methylpropanal

Show Worked Solution

Functional Group: Butan-2-one and butanal

Chain: Butanal and 2-methylpropanal

PHYSICS, M6 2023 HSC 28

An ideal transformer is connected to a 240 V AC supply. It has 300 turns on the primary coil and 50 turns on the secondary coil.

It is connected in the circuit with two identical light globes, and , as shown.
 

  1. Calculate the voltage across light globe when the switch is open. (2 marks)
  1. Explain why, after the switch has been closed, the current in the primary coil is different from when the switch is open.  (3 marks)

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a.     40 V

b.    Closed switch    globe and are connected in a parallel circuit.

→ Once the switch is closed, the total resistance through the circuit is less than when only light globe is in the circuit. 

→ Since  . Therefore, a decrease in resistance through the circuit leads to an increase in the current.

→ Transformer is ideal, so Power in = Power out ( ). Hence, an increase in corresponds to an increase in .

→ Therefore, the current in the primary coil is greater when the switch is closed.

Show Worked Solution

a.     
   
     
     

 
→ The voltage across light globe is 40 V.
 

b.    Closed switch    globe and are connected in a parallel circuit.

→ Once the switch is closed, the total resistance through the circuit is less than when only light globe is in the circuit. 

→ Since  . Therefore, a decrease in resistance through the circuit leads to an increase in the current.

→ Transformer is ideal, so Power in = Power out ( ). Hence, an increase in corresponds to an increase in .

→ Therefore, the current in the primary coil is greater when the switch is closed.

♦ Mean mark (b) 39%.

PHYSICS, M6 2023 HSC 25a

The diagram represents one type of electric motor.
 

Describe the function of part .  (2 marks)

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→ Part is a split ring commutator and its function is to reverse the direction of the current through the arms of the armature.

→ This ensures that unidirectional torque is maintained in the DC motor so that it continues to rotate in the same direction. 

Show Worked Solution

→ Part is a split ring commutator and its function is to reverse the direction of the current through the arms of the armature.

→ This ensures that unidirectional torque is maintained in the DC motor so that it continues to rotate in the same direction. 

PHYSICS, M7 2023 HSC 22

A spacecraft passes Earth at a speed of 0.9. The spacecraft emits a light pulse every 3.1 10 s, as measured by the crew on the spacecraft.

What is the time between the pulses, as measured by an observer on Earth?  (3 marks)

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Show Worked Solution

 
   
   
   

PHYSICS, M8 2023 HSC 21

A Hertzsprung–Russell diagram is shown.
 

  1. Identify TWO variables that determine the luminosity of a star  (2 marks)
  1. Describe differences between stars and .  (3 marks)
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a.    The luminosity of a star can be determined by its size and temperature.

Other variables could include:

→ Mass, colour and the power output of a star.
 

b.   Differences:

→ Star A is a main sequence star and is therefore fusing hydrogen to helium in its core via both the proton-proton chain and CNO cycle whereas Star B is a white dwarf star and therefore has no fusion taking place in its core.

→ Star A has a greater luminosity compared to Star B.

→ Star A is a younger star then Star B which is at the end of its lifecycle. 

Other differences could include:

→ Mass

→ Radius or size

Show Worked Solution

a.    The luminosity of a star can be determined by its size and temperature.

Other variables could include:

→ Mass, colour and the power output of a star.
 

b.   Differences between stars:

→ Star A is a main sequence star and is therefore fusing hydrogen to helium in its core via both the proton-proton chain and CNO cycle whereas Star B is a white dwarf star and therefore has no fusion taking place in its core.

→ Star A has a greater luminosity compared to Star B.

→ Star A is a younger star then Star B which is at the end of its lifecycle.
 

Other differences could include:

→ Mass

→ Radius or size

PHYSICS, M8 2023 HSC 11 MC

The chart shows part of a nuclear decay series beginning with uranium.
 


 

Which option correctly identifies and and the process by which each was produced?

 

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→ During the decay process producing , the Atomic number decreases by 2 to 90 and the Mass number decreases by 4 to 234

→ Alpha decay producing 

→ During the decay process producing , the Atomic number increases by 1 to 91 and the Mass number does not change. 

→ Beta decay producing

BIOLOGY, M8 2023 HSC 14 MC

Minamata Disease is caused by regular consumption of contaminated fish and shellfish. The symptoms include numbness in the hands and feet, muscle weakness, and damage to vision, hearing and speech.

Pellagra is a disease which causes delusions or mental confusion, diarrhoea, weakness and loss of appetite caused by insufficient levels of iron and niacin.

Wildervanck Syndrome is a condition that affects the bones in the neck, the eyes and the ears, and occurs primarily in females.

Given the information above, which row in the table correctly identifies the classification of these diseases?
 

  Minamata Disease Pellagra Wildervanck Syndrome
A.   Genetic Nutritional Environmental
B.   Genetic Environmental Nutritional
C.   Environmental Genetic Nutritional
D.   Environmental Nutritional Genetic
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Show Worked Solution

By Elimination:

→ Minamata is caused by consumption of contaminated seafood and is therefore environmental, not genetic (Eliminate A and B).

→ Pellagra is caused by insufficient iron and niacin levels, which are a mineral and a vitamin respectively. It is therefore a nutritional disease and not genetic (Eliminate C).

→ As Wildervanck Syndrome occurs primarily in females, there cannot be 100% certainty it is genetic. However, with all other options eliminated, it can be assumed to be the case here.

BIOLOGY, M7 2023 HSC 5 MC

An experiment was conducted to investigate the rate of binary fission in E.coli. The results of the experiment are shown.
 

Time (minutes) Number of E.coli
0 20
20 40
40 80
60 160
80 320
100 640

 
Which graph represents the data in the table?
 


  

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Show Worked Solution

By Elimination:

→ The independent variable (time) must be on the -axis (Eliminate C and D).

→ The number of E. Coli starts at 20, not 0 (Eliminate A).

BIOLOGY, M5 2023 HSC 2 MC

Which of the following is an advantage of internal fertilisation?

  1. Decreases the risk of gamete dehydration
  2. Increases the number of gametes released
  3. Increases the number of zygotes at one time
  4. Decreases the care provided to gamete and offspring
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Show Worked Solution

→ Internal fertilisation occurs in a moist environment, decreasing the risk of gamete dehydration.

Mechanics, EXT2 M1 2023 HSC 14c

A projectile of mass kg is launched vertically upwards from the origin with an initial speed m s. The acceleration due to gravity is ms.

The projectile experiences a resistive force of magnitude newtons, where is a positive constant and is the speed of the projectile at time seconds.

  1. The maximum height reached by the particle is metres.
  2. Show that  .  (3 marks)

  3. When the projectile lands on the ground, its speed is , where is less than the magnitude of the terminal velocity.
  4. Show that  .  (3 marks)

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Show Worked Solution

i.   

 
 
 
 
 
 
   

 

 
   

 


  

ii.   

 
 
 
 
 
   

 


 

 
 
 
 
 
 
 
♦♦ Mean mark (ii) 31%.

BIOLOGY, M1 EQ-Bank 1 MC

Which of the following eukaryotic organelles is correctly matched with its function?

 
   Golgi body mRNA production
  Mitochondria ATP synthesis
    Ribosome Waste storage
  Lysosome Movement
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Show Worked Solution

By Elimination

→ Golgi bodies are involved in the modification, storage and distribution of the lipids, carbohydrates and proteins made in the E.R. (Eliminate A).

→ Ribosomes carry out protein synthesis (Eliminate C).

→ Lysosomes are involved in solid waste processing (Eliminate D).

Complex Numbers, EXT2 N2 2023 14a

Let be the complex number    and be the complex number  .

  1. By first writing and in Cartesian form, or otherwise, show that
  2.    .  (3 marks)

  3. The complex numbers and are represented in the complex plane by the vectors and respectively, where is the origin.
  4. Show that  .  (2 marks)

  5. Deduce that  .  (1 mark)

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Show Worked Solution

i.   

 
   
   
   
   
   
   

 
ii.   


  

iii.   


 

 
   
   
   
   
♦♦ Mean mark (iii) 26%.

Mechanics, EXT2 M1 2023 HSC 13c

A particle of mass 1 kg is projected from the origin with speed 40 m s at an angle 30° to the horizontal plane.

  1. Use the information above to show that the initial velocity of the particle is
  2.     .   (1 mark)

The forces acting on the particle are gravity and air resistance. The air resistance is proportional to the velocity vector with a constant of proportionality 4 . Let the acceleration due to gravity be 10 m s .

The position vector of the particle, at time seconds after the particle is projected, is and the velocity vector is .
 

  1. Show that    (3 marks)

  2. Show that    (2 marks)

  3. The graphs    and  are given in the diagram below.
     
     
  4. Using the diagram, find the horizontal range of the particle, giving your answer rounded to one decimal place.  (2 marks)

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Show Worked Solution

i. 


 

ii.   

 
 
 
 
 

 

 
 
 
 

 

 
 
 
 
 
 

 

 
 
 
 
 

 
 

 
iii.   

 
   
   

 

 
   

 

 
   
   

 

 
   

 

 

iv.   

 
 
 

 

 
   
   

♦ Mean mark (iv) 43%.