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CHEMISTRY, M3 EQ-Bank 18

A student heats sodium metal, copper carbonate and propane gas \(\ce{(C3H8)}\) individually with a Bunsen burner. All of the substances react but only two of the substances react with the oxygen in the air.

Write a balanced chemical equation for each of the reactions that occurred.   (3 marks)

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Combustion of sodium metal:  \(\ce{2Na(s) + O2(g) -> 2NaO(s)}\)

Combustion of propane gas:  \(\ce{C3H8(g) + 5O2(g) -> 3CO2(g) + 4H2O(l)}\)

Decomposition of copper carbonate:  \(\ce{CuCO3(s) -> CuO(s) + CO2(g)}\)

Show Worked Solution

Combustion of sodium metal:  \(\ce{2Na(s) + O2(g) -> 2NaO(s)}\)

Combustion of propane gas:  \(\ce{C3H8(g) + 5O2(g) -> 3CO2(g) + 4H2O(l)}\)

Decomposition of copper carbonate:  \(\ce{CuCO3(s) -> CuO(s) + CO2(g)}\)

  • The last reaction is endothermic and so requires the heat of the Bunsen burner to proceed where as the first two require the heat of the Bunsen burner to overcome their activation energies.

CHEMISTRY, M3 EQ-Bank 17

A student tested how soluble silver salts are by reacting a 0.1 mol L\(^{-1}\) silver nitrate solution with 0.1 mol L\(^{-1}\) solutions of calcium hydroxide, calcium chloride, and calcium sulfate. The results are shown below:

\begin{array} {|l|l|}
\hline \ \ \ \ \ \text{Compound} & \ \ \ \ \ \text{Observation} \\
\hline \text{calcium hydroxide} & \text{No reaction} \\
\hline \text{calcium chloride} & \text{White precipitate} \\
\hline \text{calcium sulfate} & \text{No reaction} \\
\hline \end{array}

  1. Write a balanced chemical equation for the reaction with calcium chloride.   (2 marks)
  1. Name the white precipitate.   (1 mark)
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a.    \(\ce{CaCl2(aq) + 2AgNO3(aq) -> Ca(NO3)2(aq) + 2AgCl(s)}\)

b.    The white precipitate is \(\ce{AgCl}\) → silver chloride.

Show Worked Solution

a.    \(\ce{CaCl2(aq) + 2AgNO3(aq) -> Ca(NO3)2(aq) + 2AgCl(s)}\)
 

b.    The white precipitate is \(\ce{AgCl}\) → silver chloride.

CHEMISTRY, M3 EQ-Bank 29v4

Write balanced chemical equations for each of the following reactions (states of matter are not required).

  1. The reaction between aluminium and nitric acid.   (1 mark)
  2. The decomposition of mercury (II) oxide.    (1 mark)
  3. The complete combustion of pentane (\(\ce{C5H12}\)) with excess oxygen.   (1 mark)
  4. The reaction between magnesium hydroxide and acetic acid (\(\ce{CH3COOH}\)).   (1 mark)
  5. The reaction between calcium carbonate and hydrochloric acid.   (1 mark)
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a.    \(\ce{2Al + 6HNO3 -> 2Al(NO3)3 + 3H2}\)

b.    \(\ce{2HgO -> 2Hg + O2}\)

c.    \(\ce{C5H12 + 8O2 -> 5CO2 + 6H2O}\)

d.    \(\ce{Mg(OH)2 + 2CH3COOH -> Mg(CH3COO)2 + 2H2O}\)

e.    \(\ce{CaCO3 + 2HCl -> CaCl2 + CO2 + H2O}\)

Show Worked Solution

a.    Active metal and acid

\(\ce{2Al + 6HNO3 -> 2Al(NO3)3 + 3H2}\)

b.    Decomposition 

\(\ce{2HgO -> 2Hg + O2}\)

c.    Combustion

\(\ce{C5H12 + 8O2 -> 5CO2 + 6H2O}\)

d.    Acid-base

\(\ce{Mg(OH)2 + 2CH3COOH -> Mg(CH3COO)2 + 2H2O}\)

e.    Acid-carbonate

\(\ce{CaCO3 + 2HCl -> CaCl2 + CO2 + H2O}\)

CHEMISTRY, M3 EQ-Bank 29v3

Write balanced chemical equations for each of the following reactions (states of matter are not required).

  1. The reaction between iron and sulfuric acid.   (1 mark)
  2. The decomposition of sodium carbonate.   (1 mark)
  3. The incomplete combustion of propene (\(\ce{C3H6}\)) with a limited amount of oxygen.   (1 mark)
  4. The reaction between calcium hydroxide and phosphoric acid.   (1 mark)
  5. The reaction between sodium carbonate and nitric acid.   (1 mark) 
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a.    \(\ce{Fe + H2SO4 -> FeSO4 + H2}\)

b.    \(\ce{Na2CO3 -> Na2O + CO2}\)

c.    \(\ce{2C3H6 + 9O2 -> 6CO + 6H2O}\)

d.    \(\ce{3Ca(OH)2 + 2H3PO4 -> Ca3(PO4)2 + 6H2O}\)

e.    \(\ce{Na2CO3 + 2HNO3 -> 2NaNO3 + CO2 + H2O}\)

Show Worked Solution

a.    Active metal and acid

\[\ce{Fe + H2SO4 -> FeSO4 + H2}\]

b.    Decomposition

\[\ce{Na2CO3 -> Na2O + CO2}\]

c.   Combustion

\[\ce{2C3H6 + 9O2 -> 6CO + 6H2O}\]

d.    Acid-Base

\[\ce{3Ca(OH)2 + 2H3PO4 -> Ca3(PO4)2 + 6H2O}\]

e.    Acid-Carbonate

\[\ce{Na2CO3 + 2HNO3 -> 2NaNO3 + CO2 + H2O}\]

CHEMISTRY, M3 EQ-Bank 16

Write balanced chemical equations for each of the following reactions (states of matter are not required).

  1. The reaction between lithium hydroxide and hydrochloric acid.   (1 mark)

  2. The reaction between potassium carbonate and hydrochloric acid.   (1 mark)

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a.    \(\ce{LiOH + HCl -> LiCl + H2O}\)

b.    \(\ce{K2CO3 + 2HCl -> 2KCl + CO2 + H2O}\)

Show Worked Solution

a.    Acid-Base

\[\ce{LiOH + HCl -> LiCl + H2O}\]

b.    Acid-carbonate

\[\ce{K2CO3 + 2HCl -> 2KCl + CO2 + H2O}\]

CHEMISTRY, M3 EQ-Bank 15

Write balanced chemical equations for each of the following reactions (states of matter are not required).

  1. The reaction between zinc and sulfuric acid.   (1 mark)

  2. The decomposition of calcium carbonate.   (1 mark)

  3. The incomplete combustion of ethane \(\ce{(C2H6)}\) with a limited amount of oxygen.   (1 mark)

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a.    \(\ce{Zn + H2SO4 -> ZnSO4 + H2}\)

b.    \(\ce{CaCO3 -> CaO + CO2}\)

c.    \(\ce{2C2H6 + 5O2 -> 4CO + 6H2O}\)

Show Worked Solution

a.    Active metal and acid

\[\ce{Zn + H2SO4 -> ZnSO4 + H2}\]

b.    Decomposition

\[\ce{CaCO3 -> CaO + CO2}\]

c.    Combustion

\[\ce{2C2H6 + 5O2 -> 4CO + 6H2O}\]

CHEMISTRY, M3 EQ-Bank 14

Write balanced chemical equations for each of the following reactions (states of matter are not required).

  1. The reaction between potassium hydroxide and sulfuric acid.   (1 mark)
  2. The reaction between sodium bicarbonate \(\ce{(NaHCO3)}\) and acetic acid \(\ce{(CH3COOH)}\).   (1 mark)
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a.    \(\ce{2KOH + H2SO4 -> K2SO4 + 2H2O}\)

b.    \(\ce{NaHCO3 + CH3COOH -> CH3COONa + CO2 + H2O}\)

Show Worked Solution

a.   Acid-base 

\(\ce{2KOH + H2SO4 -> K2SO4 + 2H2O}\)

b.   Acid-carbonate 

\(\ce{NaHCO3 + CH3COOH -> CH3COONa + CO2 + H2O}\)

CHEMISTRY, M3 EQ-Bank 13

Write balanced chemical equations for each of the following reactions (states of matter are not required).

  1. The reaction between magnesium and hydrochloric acid.   (1 mark)

  2. The decomposition of ammonia.   (1 mark)

  3. The incomplete combustion of butane (\(\ce{C4H10}\)) with a limited amount of oxygen.   (1 mark)

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a.    \(\ce{Mg + 2HCl -> MgCl2 + H2}\)

b.    \(\ce{2NH3 -> N2 + 3H2}\)

c.    \(\ce{2C4H10 + 9O2 -> 8CO + 10H2O}\)

Show Worked Solution

a.   Reaction between active metal and acid

\(\ce{Mg + 2HCl -> MgCl2 + H2}\)

b.   Decomposition

\(\ce{2NH3 -> N2 + 3H2}\)

c.   Combustion

\(\ce{2C4H10 + 9O2 -> 8CO + 10H2O}\)

CHEMISTRY, M3 EQ-Bank 9

Two moles of butane \(\ce{C3H8(g)}\) were reacted with 224 grams of oxygen \(\ce{O2(g)}\).

  1. Write the balanced equation for this reaction.   (3 marks)
  2. Determine the mass, in grams, of \(\ce{CO2(g)}\) produced by this reaction.   (1 mark)
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a.    \(\ce{2C3H8(g) + 7O2(g)\ \rightarrow 2C(s) + 2CO(g) + 2CO2(g) + 8H2O(l)}\)

b.    \(\ce{m(CO2) = 88.02\ \text{g}}\)

Show Worked Solution

a.    Complete combustion equation:

   \(\ce{C3H8(g) + 5O2(g)\ \rightarrow 3CO2(g) + 4H2O(l)} \)

  • Two moles of butane require 10 moles of oxygen to fully combust. 
  •    \(\ce{n(O2) = \dfrac {m}{MM}= \dfrac {224}{32} = 7}\)
  • Oxygen is limiting reagent and butane will undergo incomplete combustion according to the following balanced equation:
  •    \(\ce{2C3H8(g) + 7O2(g)\ \rightarrow 2C(s) + 2CO(g) + 2CO2(g) + 8H2O(l)}\)

b.    Using the equation in part (i), 2 moles of \(\ce{CO2}\) will be produced

   \(\ce{m(CO2) = n \times MM = 2 \times 44.01 = 88.02\ \text{g}}\)

CHEMISTRY, M3 EQ-Bank 6

Three unknown metals are reacted with dilute \(\ce{HCl(aq)}\) and the following observations are made:  

\begin{array} {|c|l|}
\hline
\rule{0pt}{2.5ex} \textit{Metal} \rule[-1ex]{0pt}{0pt} & \ \ \ \ \ \ \textit{Observations} \\
\hline
\rule{0pt}{2.5ex} \text{A} \rule[-1ex]{0pt}{0pt} & \text{No observable reaction} \\
\hline
\rule{0pt}{2.5ex} \text{B} \rule[-1ex]{0pt}{0pt} & \text{Slow bubbling} \\
\hline
\rule{0pt}{2.5ex} \text{C} \rule[-1ex]{0pt}{0pt} &  \text{Fast, abrupt bubbling} \\
\hline
\end{array}

You are told that the metals in question are Magnesium, Platinum and Zinc.

  1. Explain which of the above metals correspond to \(\text{A}\), \(\text{B}\) and \(\text{C}\), giving reasons for your answer.   (3 marks) 

  2. Describe the type of reaction between \(\ce{HCl}\) and metal \(\ce{C}\).   (1 mark)

  3. Provide one balanced chemical equation between \(\ce{HCl}\) and either metal \(\text{B}\) or metal \(\text{C}\).   (1 mark)

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a.    Identifying metals \(\text{A}\), \(\text{B}\) and \(\text{C}\):

  • The metals \(\text{A}\), \(\text{B}\) and \(\text{C}\) differ by their relative reactivity.
  • Magnesium is the most reactive as it is an alkali earth metal (Metal \(\text{C}\)).
  • Zinc and Platinum are both less reactive than magnesium. Zinc however exists higher on the reactivity series of metals than Platinum which is the least reactive of the three metals.
  • Therefore, metal \(\text{B}\) is zinc and metal \(\text{A}\) is platinum. 

b.   A single displacement reaction.
 

c.    Include one of the following:

\(\ce{Mg(s) + 2HCl(aq) \rightarrow MgCl2(aq) + H2(g) }\)

\(\ce{Zn(s) + 2HCl(aq) \rightarrow ZnCl2(aq) + H2(g) }\)

Show Worked Solution

a.    Identifying metals \(\text{A}\), \(\text{B}\) and \(\text{C}\):

  • The metals \(\text{A}\), \(\text{B}\) and \(\text{C}\) differ by their relative reactivity.
  • Magnesium is the most reactive as it is an alkali earth metal (Metal \(\text{C}\)).
  • Zinc and Platinum are both less reactive than magnesium. Zinc however exists higher on the reactivity series of metals than Platinum which is the least reactive of the three metals.
  • Therefore, metal \(\text{B}\) is zinc and metal \(\text{A}\) is platinum. 

b.   A single displacement reaction.
 

c.    Include one of the following:

\(\ce{Mg(s) + 2HCl(aq) \rightarrow MgCl2(aq) + H2(g) }\)

\(\ce{Zn(s) + 2HCl(aq) \rightarrow ZnCl2(aq) + H2(g) }\)

CHEMISTRY, M3 EQ-Bank 5

Write a balanced chemical equation for the complete combustion of butane \(\ce{(C4H10)}\).   (2 marks)

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\(\ce{2C4H10(aq) + 13O2(g) \rightarrow 8CO2(g) + 10H2O(l)}\)

Show Worked Solution
  • Products of complete combustion are: \(\ce{CO2,\ H2O}\)
  • Balanced equation:
  •    \(\ce{2C4H10(aq) + 13O2(g) \rightarrow 8CO2(g) + 10H2O(l)}\)

CHEMISTRY, M3 EQ-Bank 4

When aqueous lead \(\text{(II)}\) nitrate \(\ce{(Pb(NO3)2)}\) is mixed with a potassium iodide solution \((\ce{KI}) \), a precipitation of lead \(\text{(II)}\) iodide \(\ce{(PbI2)}\) results.

Write a balanced chemical equation for this precipitation reaction.  (2 marks)

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\(\ce{Pb(NO3)2(aq) + 2KI(aq) \rightarrow PbI2(s) + 2KNO3(aq)}\)

Show Worked Solution
  • Reaction products: \(\ce{PbI2,\ KNO3}\)
  • Balanced equation:
  •    \(\ce{Pb(NO3)2(aq) + 2KI(aq) \rightarrow PbI2(s) + 2KNO3(aq)}\)

CHEMISTRY, M3 EQ-Bank 3

Identify the products when solid calcium carbonate \(\ce{(CaCO3)}\) reacts with aqueous nitric acid \(\ce{(HNO3)}\) and write the balanced chemical equation for the reaction.   (3 marks)

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\(\ce{CaCO3_{(s)} + 2HNO3_{(aq)} \rightarrow H2O_{(l)} + CO2_{(g)} + Ca(NO3)2_{(aq)}}\)

Show Worked Solution
  • Solid calcium carbonate and nitric acid produce: \(\ce{H2O(l),\ CO2(g), Ca(NO3)2(aq)} \).
  • Balanced equation:
  •    \(\ce{CaCO3(s) + 2HNO3(aq) \rightarrow H2O(l) + CO2(g) + Ca(NO3)2(aq)}\)