Enthalpy Change - Practice Questions & MCQ

Given C_(graphite)+O₂(g) → CO₂(g) ;

_rH⁰=−393.5 kJ mol⁻¹

H₂(g)+ O₂(g) → H₂O(l) ;

rH⁰=−285.8 kJ mol⁻¹

CO₂(g)+2H₂O(l) → CH₄(g)+2O₂(g) ;

_rH⁰=+890.3 kJ mol⁻¹

Based on the above thermochemical equations, the value of _rH⁰ at 298 K for the reaction

C_(graphite)+2H₂(g) → CH₄(g) will be :

The standard enthalpy change  for a reaction is . Calculate the heat (q) released when 2 moles of the reaction take place at constant pressure.

An ideal gas undergoes a reversible isobaric expansion at a constant pressure of . The gas absorbs of heat and its temperature increases by . Calculate the change in heat enthalpy of the gas. Given the heat capacity at constant pressure for the gas is
 

An ideal gas undergoes a reversible isobaric expansion at a constant pressure of . The gas absorbs  of heat and its temperature increases by . Calculate the change in heat enthalpy of the gas. Given the heat capacity at constant pressure for the gas is
 

An ideal gas undergoes a reversible isobaric expansion at a constant pressure of The gas absorbs of heat and its temperature increases by . Calculate the change in heat enthalpy of the gas. Given the heat capacity at constant pressure for the gas is
 

A chemical reaction is carried out in a bomb calorimeter. The temperature of the calorimeter increases from upon the reaction. The heat capacity of the calorimeter (including the water) is . Calculate the heat released by the reaction.
 

When 9 in ice melts at  0⁰ C, x KJ heat is required, then enthalpy of fusion of ice will be 

Using the following reactions and their respective enthalpy changes, calculate the enthalpy change for the reaction:

$
2 \mathrm{C}(\text { graphite })+\mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{CO}(\mathrm{~g})
$

Reactions:
1. C (graphite) $+\mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{CO}_2(\mathrm{~g})$ with $\Delta \mathrm{H}^{\circ}=-393.5 \mathrm{~kJ} / \mathrm{mol}$
2. $\mathrm{CO}_2(\mathrm{~g}) \rightarrow \mathrm{CO}(\mathrm{g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g})$ with $\Delta \mathrm{H}^{\circ}=-283.0 \mathrm{~kJ} / \mathrm{mol}$