Which of the following reactions is endothermic?

If for the reaction $CCl_{4(g)} \rightarrow C_{(g)} + 4Cl_{(g)}$ the following data is given:
$\Delta_{vap} H^{\theta} (CCl_{4(l)}) = 30 \ kJ \ mol^{-1}$
$\Delta_{f} H^{\theta} (CCl_{4(l)}) = -136.0 \ kJ \ mol^{-1}$
$\Delta_{a} H^{\theta} (C_{(s)}) = 714.0 \ kJ \ mol^{-1}$
$\Delta_{a} H^{\theta} (Cl_{2(g)}) = 242.0 \ kJ \ mol^{-1}$
Calculate the mean bond enthalpy of $C-Cl$ in $CCl_{4(g)}$.

Equal volumes of methanoic acid and sodium hydroxide are mixed. If $x$ is the heat of formation of water,then the heat evolved on neutralization is

The enthalpy of the reaction,$H_{2(g)} + \frac{1}{2}O_{2(g)} \to H_2O_{(g)}$ is $\Delta H_1$ and that of $H_{2(g)} + \frac{1}{2}O_{2(g)} \to H_2O_{(l)}$ is $\Delta H_2$. Then:

Which of the following statements is correct about the heat of combustion?

$XeF_{2(g)} + H_{2(g)} \to 2HF_{(g)} + Xe_{(g)}$,$\Delta H^o = -430 \ kJ$
Bond energy:
$H-H = 435 \ kJ/mol$
$H-F = 565 \ kJ/mol$
Calculate the average bond energy of the $Xe-F$ bond in $kJ/mol$.