For the combustion reaction $2C_8H_{18}(g) + 25O_2(g) \rightarrow 16CO_2(g) + 18H_2O(g)$,what are the signs of $\Delta H$,$\Delta S$,and $\Delta G$?

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

For silver,$C_P \, (J \, K^{-1} \, mol^{-1}) = 23 + 0.01 \, T$. If the temperature $(T)$ of $3 \, moles$ of silver is raised from $300 \, K$ to $1000 \, K$ at $1 \, atm$ pressure,the value of $\Delta H$ will be close to $kJ$.

For the reaction: $A_{(g)} + B_{(s)} \rightleftharpoons 2C_{(g)} + D_{(g)}$,given $\Delta U = 5.0 \ kcal$ and $\Delta S = 50 \ cal \ K^{-1}$ at $400 \ K$. Calculate $\Delta G$ for the reaction. (in $kcal$)

From the following data,the enthalpy of dilution of $KCl$ will be ............ $kJ$.
$KCl_{(s)} + 20H_2O \to KCl(20H_2O); \Delta H = + 15.90 \ kJ$
$KCl_{(s)} + 200H_2O \to KCl(200H_2O); \Delta H = + 18.58 \ kJ$

At $25$ $^\circ C$ and $1$ $atm$ pressure,the enthalpies of formation of $C_2H_4(g)$,$CO_2(g)$,and $H_2O(l)$ are $52$,$-394$,and $-286 \, kJ \, mol^{-1}$ respectively. The enthalpy of combustion of $C_2H_4$ is ....... $kJ \, mol^{-1}$.