VCE Chemistry Unit 3 Area of Study 1

The best definition of a fuel is

_{^{Chapter 2 (carbon based fuels)}}

• a reactant in an exothermic reaction.

• a carbon compound or an alkane.

• a compound that releases significant amounts of energy easily.

• a compound with a high level of stored energy.

Which of the following is a correct thermochemical equation?

^{(Chapter 2 Carbon based fuels)}

• C₂H_6(g) + 3.5O_2(g) -> 2CO_2(g) + 3H₂O_(l)

  ∆H= -1560 kJ mol^-1

• 2C₂H_6(g) + 7O_2(g) -> 4CO_2(g) + 6H₂O_(g)

  ∆H= -1560 kJ mol^-1

• 2C₂H_6(g) + 7O_2(g) -> 4CO_2(g) + 6H₂O_(g)

  ∆H= -3120 kJ mol^-1

• 2C₂H_6(g) + 7O_2(g) -> 4CO_2(g) + 6H₂O_(l)

  ∆H= -3120 kJ

^{(Chapter 2 Carbon based fuels)}

An energy profile diagram is shown on the left.

In the reaction represented by the diagram, the

• enthalpy of the products is less than that of the reactants and energy is released to the surroundings

• enthalpy of the products is greater than that of the reactants and energy is released to the surroundings.

• enthalpy of the products is less than that of the reactants and energy is absorbed from the surroundings.

• enthalpy of the products is greater than that of the reactants and energy is absorbed from the surroundings.

^{(Chapter 2 Carbon based fuels)}

Which of the following food sources can provide the body with the greatest amount of energy?

• 10 g of sugar and 5 g of peanut oil

• 5 g of sugar, 5 g of protein and 5 g of peanut oil

• 24 g of sugar

• 12 g of peanut oil

^{(Chapter 2 Carbon based fuels)}

Select the correct statement about fermentation.

• Fermentation converts any sugar into ethanol.

• Fermentation will produce pure ethanol if the reaction is allowed to continue long enough.

• Fermentation usually produces an ethanol solution of concentration around 12 (%v/v).

• Fermentation requires oxygen gas.

^{(Chapter 2 Carbon based fuels)}

Compared to petrol, E10 fuel

• has a higher energy density

• is more likely to absorb traces of water.

• leads to more rapid engine deterioration.

• emits a lower volume of gas per kilometre during combustion

^{(Chapter 3 Energy from fuels)}

The equation for the reaction between aluminium metal and oxygen gas is

4Al_(s) + 3O_2(g) --> 2Al₂O_3(s) ΔH = - 130 kJ

The amount of energy released from the complete combustion of 0.200 mol of aluminium is

• 6.5 kJ

• 13 kJ

• 52kJ

• 520 kJ

^{(Chapter 3 Energy from fuels)}

The equation for the reaction between aluminium metal and oxygen gas is

4Al_(s) + 3O_2(g) --> 2Al₂O_3(s) ΔH = - 130 kJ

The volume of oxygen gas required at SLC to react with 0.200 mol of aluminium is, in L,

• 1.86

• 3.72

• 4.96

• 6.40

^{(Chapter 3 Energy from fuels)}

The equation for the reaction between aluminium metal and oxygen gas is

4Al_(s) + 3O_2(g) --> 2Al₂O_3(s) ΔH = - 130 kJ

0.36 mol of aluminium is reacted with 0.24 mol of oxygen gas. The amount of reactant remaining after the reaction is

• no reactants remain

• 0.040 mol aluminium

• 0.040 mol oxygen

• 0.12 mol aluminium

^{(Chapter 3 changes in chemical reactions)}

The specific heat capacity of iron is

• the energy required to raise the temperature of 1.0 mole of iron by 1.0°C.

• the energy required to raise the temperature of 1.0 g of iron by 1.0°C.

• the energy released by the combustion of 1.0 g of iron.

• the energy required to raise the temperature of water in a iron vessel by 1.0°C.