The heat of reaction for $C_2H_2 + H_2 \rightarrow C_2H_4$ is given by the following data:
$(i) \Delta H_f^o \text{ of } H_2O_{(\ell)} = -68.3 \ K \ cal \ mol^{-1}$
$(ii) \Delta H_{comb}^o \text{ of } C_2H_2 = -337.2 \ K \ cal \ mol^{-1}$
$(iii) \Delta H_{comb}^o \text{ of } C_2H_4 = -363.7 \ K \ cal \ mol^{-1}$

For a dimerization reaction,$2 A_{(g)} \rightarrow A_{2(g)}$ at $298 \ K$,$\Delta U^{\ominus} = -20 \ kJ \ mol^{-1}$,$\Delta S^{\ominus} = -30 \ J \ K^{-1} \ mol^{-1}$,then the $\Delta G^{\ominus}$ will be........ $J$

In an irreversible process taking place at constant $T$ and $P$ and in which only pressure-volume work is being done,the change in Gibbs free energy $(dG)$ and change in entropy $(dS)$ satisfy the criteria:

$200 \ mL$ of $0.2 \ M \ HCl$ is mixed with $300 \ mL$ of $0.1 \ M \ NaOH$. The molar heat of neutralization of this reaction is $-57.1 \ kJ \ mol^{-1}$. The increase in temperature in $^{\circ}C$ of the system on mixing is $x \times 10^{-2}$. The value of $x$ is ....... . (Nearest integer)
[Given : Specific heat of water $= 4.18 \ J \ g^{-1} \ K^{-1}$
Density of water $= 1.00 \ g \ cm^{-3}$]
(Assume no volume change on mixing)

Products are favoured in a chemical reaction taking place at a constant temperature and pressure. Consider the following statements: $(i)$ The change in Gibbs energy for the reaction is negative. $(ii)$ The total change in Gibbs energy for the reaction and the surroundings is negative. $(iii)$ The change in entropy for the reaction is positive. $(iv)$ The total change in entropy for the reaction and the surroundings is positive. The statements which are always true are:

$A$ gas present in a cylinder expands against a constant pressure of $1 \, atm$ from a volume of $2 \, L$ to a volume of $6 \, L$. In doing so,it absorbs $800 \, J$ of heat from the surroundings. The change in internal energy of the process is ....... $J$.