Question

Calculate the energy change per gram of sucrose for this combustion reaction.

a) ∆H = mcΔT
b) ∆H = q/m
c) ∆H = nΔH°
d) ∆H = ∆U + P∆V

Answer 1

The enthalpy change per gram of sucrose in a combustion reaction is calculated using the thermochemical equation provided from the combustion of 2.67 g of sucrose, resulting in -16.378 kJ/g.

Step-by-step explanation:

To calculate the energy change per gram of sucrose for a combustion reaction, we can use the concept of enthalpy change. This process will involve the use of a balanced chemical equation and thermochemical data.

First, we would write the balanced chemical equation for the combustion of sucrose. The reaction of one mole of sucrose with potassium chlorate is given by:

C12H22O11 (aq) + 8KClO3(aq) → 12CO2(g) + 11H2O(l) + 8KCl(aq)

To determine the enthalpy change (ΔH comb) per gram of sucrose, we use the thermochemical equation. From the example given, we know that the combustion of 2.67 g of sucrose releases 43.7 kJ of heat:

ΔH comb = -43.7 kJ / 2.67 g = -16.378 kJ/g

This result represents the energy change per gram of sucrose during the combustion reaction.