Calculate the quantity of heat released from system when 2 moles of and ideal gas compressed isothermally from volume $25 \text{ dm}^3$ to $10 \text{ dm}^3$ at constant external pressure 4 bar.

Calculate the standard enthalpy of combustion of carbon monoxide if
$\Delta_f H^\circ (\text{CO}) = -110 \text{ kJ mol}^{-1}$
$\Delta_f H^\circ (\text{CO}_2) = -393 \text{ kJ mol}^{-1}$

Which of the following processes is an endothermic ?

The solubility of sapringly soluble salt $\text{AB}_2$ is $18 \cdot 78 \times 10^{-4} \text{ g/dm}^3$ What is its solubility product ? (Molar mass of $\text{AB}_2 = 187 \cdot 8 \text{ g mol}^{-1}$)