For which one of the following equations is $\Delta H_{react}^o$ equal to $\Delta H_f^o$ for the product?

Explain the standard enthalpy of combustion $\left( \Delta_{c} H^{\theta} \right)$.

If heat of neutralization is $-13.7 \, KCal$ at $25 \, ^oC$ and $\Delta H_f^o (H_2O) = -68 \, KCal$,then the standard enthalpy of formation of $OH^{-}$ will be.....$KCal$. (in $.3$)

Fill in the blanks:
$(i)$ The enthalpy change that occurs when one mole of a compound is formed from its constituent elements in their standard states is called the ....... of that compound.
$(ii)$ The total heat change in a chemical reaction is equal to the algebraic sum of the heat changes of the individual steps of the reaction. This law was given by .......... .
$(iii)$ $A$ process during which there is no exchange of heat between the system and the surroundings is called an ........... process.

The standard enthalpy of formation of $H_2O_{(g)}$ at $298 \ K$ is $-241.82 \ kJ \ mol^{-1}$. Calculate the enthalpy of formation of $H_2O_{(g)}$ at $373 \ K$,assuming $C_p$ is independent of temperature.
$C_p$ of $H_2O_{(g)} = 33.58 \ J \ K^{-1} \ mol^{-1}$
$C_p$ of $H_{2(g)} = 28.84 \ J \ K^{-1} \ mol^{-1}$
$C_p$ of $O_{2(g)} = 29.37 \ J \ K^{-1} \ mol^{-1}$

Which of the following reactions satisfies the following conditions?
$(a)$ Heat of combustion reaction
$(b)$ Heat of formation reaction
$(c)$ An exothermic reaction
$(d)$ Not a neutralization reaction