Thermochemistry Theory

What is the correct definition for heat of combustion?

• The heat change when one mole of the substance is completely burned in excess oxygen.

• The heat change that takes place when one mole of a compound in its standard state is formed from its elements in their standard states.

• The heat change when the number of moles of reactants indicated in the balanced equation for the reaction react completely.

• The heat change when 1 mole of H⁺ ions from an acid reacts with 1 mole of OH^- ions from base.

What is the correct definition for heat of formation?

• The heat change when one mole of the substance is completely burned in excess oxygen.

• The heat change that takes place when one mole of a compound in its standard state is formed from its elements in their standard states.

• The heat change when the number of moles of reactants indicated in the balanced equation for the reaction react completely.

• The heat change when 1 mole of H⁺ ions from an acid reacts with 1 mole of OH^- ions from base.

What is the correct definition for heat of neutralisation?

• The heat change when one mole of the substance is completely burned in excess oxygen.

• The heat change that takes place when one mole of a compound in its standard state is formed from its elements in their standard states.

• The heat change when the number of moles of reactants indicated in the balanced equation for the reaction react completely.

• The heat change when 1 mole of H⁺ ions from an acid reacts with 1 mole of OH^- ions from base.

What is the correct definition for heat of reaction?

• The heat change when one mole of the substance is completely burned in excess oxygen.

• The heat change that takes place when one mole of a compound in its standard state is formed from its elements in their standard states.

• The heat change when the number of moles of reactants indicated in the balanced equation for the reaction react completely.

• The heat change when 1 mole of H⁺ ions from an acid reacts with 1 mole of OH^- ions from base.

Which of the equations below represents the heat of formation of water?

• 2H_2(g) + O_2(g) → 2H₂O_(g)

• H_2(g) + O_2(g) → H₂O_(g)

• H_2(g) + O_2(g) → H₂O_(l)

Thermochemical equations are ​ (a)   chemical equations that include the ​ (b)   of reactants and products and the ​ (c)   , ΔH.

• balanced
• physical state
• heat of reaction

The laboratory apparatus used to measure the heat of combustion of fuels and foodstuff is a bomb calorimeter. Reorder the steps so they are in the correct order.

• Place a known amount of the substance in the crucible of the bomb calorimeter.

• Fill the bomb with excess oxygen under pressure.

• Place the bomb in a known quantity of water.

• Ignite the substance electrically using an ignition coil of wire.

• Find the heat produced using the rising temperature and the heat capacity of the system (i.e., using the equation Q = mcΔT).