When $50 \ cm^3$ of a strong acid is added to $50 \ cm^3$ of an alkali,the temperature rises by $5 \ ^oC$. If $250 \ cm^3$ of each liquid are mixed,the temperature rise would be $... \ ^oC$.

Given that the bond energy of $H-H$ bonds is $436 \ kJ/mol$,$O-H$ bonds is $464 \ kJ/mol$,and $O=O$ bonds is $496 \ kJ/mol$,what is the approximate heat of reaction for $2H_2 + O_2 \longrightarrow 2H_2O$ in $kJ/mol$?

Calculate the heat of combustion (in $kJ$) of methane from the following data:
$(i)$ $C_{\text{(graphite)}} + 2H_{2(g)} \rightarrow CH_{4(g)} \quad \Delta H = -74.8 \ kJ$
(ii) $C_{\text{(graphite)}} + O_{2(g)} \rightarrow CO_{2(g)} \quad \Delta H = -393.5 \ kJ$
(iii) $H_{2(g)} + 1/2 O_{2(g)} \rightarrow H_2O_{(l)} \quad \Delta H = -286.2 \ kJ$

Calculate the heat of formation for propene $(C_3H_6)$ using the following thermochemical equations:
$(i) C_{(s)} + O_{2(g)} \to CO_{2(g)}; \Delta H_1 = -94.05 \ k.cal/mole$
$(ii) H_{2(g)} + \frac{1}{2} O_{2(g)} \to H_2O_{(l)}; \Delta H_2 = -68.32 \ k.cal/mole$
$(iii) C_3H_{6(g)} + \frac{9}{2} O_{2(g)} \to 3 CO_{2(g)} + 3 H_2O_{(l)}; \Delta H_3 = -499.7 \ k.cal/mole$
(Note: The original question provided propane combustion data; assuming propene combustion data for consistency).

The heat of solution of anhydrous $CuSO_4$ and $CuSO_4 \cdot 5 H_2 O$ are $-70 \ kJ \ mol^{-1}$ and $+12 \ kJ \ mol^{-1}$ respectively. The heat of hydration of $CuSO_4$ to $CuSO_4 \cdot 5 H_2 O$ is $-x \ kJ$. The value of $x$ is:

The heats of combustion of carbon and carbon monoxide are $-393.5 \ kJ \ mol^{-1}$ and $-283.5 \ kJ \ mol^{-1},$ respectively. The heat of formation (in $kJ \ mol^{-1}$) of carbon monoxide per mole is: