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

One mole of water at $100\,^{\circ}C$ is converted into steam at $100\,^{\circ}C$ at a constant pressure of $1\,atm$. The change in entropy is [heat of vaporisation of water at $100\,^{\circ}C = 540\,cal/g$].

Predict in which of the following,entropy increases or decreases:
$(i)$ $A$ liquid crystallizes into a solid.
$(ii)$ Temperature of a crystalline solid is raised from $0 \, K$ to $115 \, K$.
$(iii)$ $2NaHCO_{3(s)} \to Na_2CO_{3(s)} + CO_{2(g)} + H_2O_{(g)}$
$(iv)$ $H_{2(g)} \to 2H_{(g)}$

Calculate the entropy change when $1 \, \text{mole}$ of ice is converted into water at $0 \, ^\circ\text{C}$. (The enthalpy change for the conversion of ice to liquid at $0 \, ^\circ\text{C}$ is $6.0 \, \text{kJ} \, \text{mol}^{-1}$).

Calculate the entropy change in the surroundings when $1.00 \ mol$ of $H_2O_{(l)}$ is formed under standard conditions. Given: $\Delta_f H^{\theta} = -286 \ kJ \ mol^{-1}$.

What is the entropy change in $J K^{-1}$ during the melting of $27.3 \ g$ of ice at $0^{\circ} C$? (Latent heat of fusion of ice $= 330 \ J g^{-1}$)