(A) Vanillin is a natural constituent of vanilla. It is also manufactured for use in artificial vanilla flavoring. The combustion of 1.013 g of vanillin, C₈H₈O₃, in the same bomb calorimeter as in Example 7-3 causes the temperature to rise from 24.89 to 30.09 °C. What is the heat of combustion of vanillin, expressed in kilojoules per mole?

(B) The heat of combustion of benzoic acid, C₆H₅COOH(s), is -26.42 kJ/g. One method of obtaining the heat capacity of a bomb calorimeter is to measure the temperature change produced by the combustion of a given mass of benzoic acid. If the combustion of a 1.176 g sample of benzoic acid causes a temperature increase of 4.96 °C in a bomb calorimeter assembly, what is the heat capacity of the assembly?

Example 7-3

The combustion of 1.010 g sucrose, C₁₂H₂₂O₁₁, in a bomb calorimeter causes the temperature to rise from 24.92 to 28.33 °C. The heat capacity of the calorimeter assembly is 4.90 kJ/°C. 

(a) What is the heat of combustion of sucrose expressed in kilojoules per mole of C₁₂H₂₂O₁₁?

(b) Verify the claim of sugar producers that one teaspoon of sugar (about 4.8 g) contains only 19 Calories.