Which of the following symbols represent heat of reaction at constant volume?

Calculate the entropy change for melting 1 g ice at $0^{\circ} \mathrm{C}$ in $\mathrm{Jg}^{-1} \mathrm{~K}^{-1}$ if heat of fusion of ice at $0^{\circ} \mathrm{C}$ is $80 \mathrm{~J} \mathrm{~K}^{-1}$.

Which of the following set of properties is correct when one mole of a gas is heated keeping volume constant by increasing temperature and supplying 500 J of heat?

Find value of Q from following equations.

(i) $\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \longrightarrow \mathrm{CO}_{2(\mathrm{~g})} \Delta \mathrm{H}=\mathrm{QkJ}$

(ii) $\mathrm{C}_{(\mathrm{s})}+\frac{1}{2} \mathrm{O}_{2(8)} \longrightarrow \mathrm{CO}_{2(8)} \Delta \mathrm{H}=-\mathrm{x} \mathrm{kJ}$

(iii) $\mathrm{C}_{(\mathrm{s})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~s})} \longrightarrow \mathrm{CO}_{2(\mathrm{~g})} \Delta \mathrm{H}=-\mathrm{ykJ}$