For the reaction $2Cl_{(s)} \to Cl_{2(s)}$,the signs of $\Delta H$ and $\Delta S$ respectively are

Calculate the work done in $J$ when $63.50 \ g$ of $Zn$ is dissolved in an open beaker with hydrochloric acid at $300 \ K$. (Atomic mass of $Zn = 63.5 \ amu$)

Which one of the following is always not negative?

One mole of an ideal monoatomic gas at temperature $T$ expands adiabatically in an insulated flask from $1 \ L$ to $2 \ L$ against an external pressure of $1 \ atm$. What is the final temperature?

Enthalpy of combustion of $CH_4, C_2H_6$ and $C_3H_8$ are $-210.8, -368.4$ and $-526.2 \ k \ cal \ mol^{-1}$ respectively. Enthalpy of combustion of hexane can be predicted as........$k \ cal \ mol^{-1}$

For the reaction $2H_{(g)} \to H_{2(g)}$,the signs of $\Delta H$ and $\Delta S$ are: