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CHEMISTRY, M2 EQ-Bank 13

  1. Calculate the volume of solution needed to obtain 0.6 moles of solute from a solution of concentration 1.2 mol/L.   (1 mark)
  1. Explain the significance of accurate volume measurements when preparing solutions of specific concentrations in the laboratory.   (2 marks)
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a.   

b.    The exact volumes of solutions must be known as:

→ The concentration of each solution must be precise, as it affects the molar ratios and yields.

→ Miscalculating volume would lead to incorrect concentrations, impacting experimental results and validity.

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a.   
 

b.    The exact volumes of solutions must be known as:

→ The concentration of each solution must be precise, as it affects the molar ratios and yields.

→ Miscalculating volume would lead to incorrect concentrations, impacting experimental results and validity.

CHEMISTRY, M2 EQ-Bank 5

The compound potassium nitrate has the formula .

  1. A student makes a solution of this compound by dissolving 40.0 g in 250.0 mL of distilled water. Calculate the concentration of this solution in mol L.   (2 marks)
  1. The student now requires 500.0 mL of a 5.0% (w/v) solution. What volume of the solution in part (a) is required to make this?   (3 marks)
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a.    

b.    

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a.    

Concentration of solution

 

b.    A 5% solution requires 5 grams of solute in 100 mL of solution.

Therefore a 500 mL solution requires 25 grams of solute.

 
 
 
 

CHEMISTRY, M2 EQ-Bank 2 MC

What volume of 0.50 M hydrochloric acid  is required to neutralise 25.0 mL of 0.40 M sodium hydroxide?

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→ Calculate the number of moles of :

→ Since the ratio of hydrochloric acid to sodium hydroxide is , the number of moles of hydrochloric acid required is also 0.0100 mol.

→ Calculate the volume of hydrochloric acid required:

CHEMISTRY, M2 2013 HSC 17* MC

A 25.0 mL sample of a 0.100 mol L hydrochloric acid solution completely reacted with 23.4 mL of sodium hydroxide solution.

Given the two equations above. What volume of the same sodium hydroxide solution would be required to completely react with 25.0 mL of a 0.100 mol L acetic acid solution ?

  1. Less than  23.4 mL
  2. 23.4 mL
  3. More than  23.4 mL
  4. Unable to calculate unless the concentration of the sodium hydroxide solution is also known
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→ The strength of the acid does not affect the volume of required for nuetralisation.

→ It is dependent on stoichiometric ratios and both and are monoprotic and so react in 1:1 ratio with sodium hydroxide.