Determine the enthalpy change for the specified reaction:

2H₂O₂(l) $\to$ 2H₂O(l) + O₂(g).

(Given the heat of formation of H₂O₂(l) and H₂O(l) are –188 and –286 kJ/mol respectively)       

Enthalpy of the reaction,

CH₄(g) + 1/2O₂(g) $\to$CH₃OH(l), is negative. If the enthalpy of combustion of CH₄ and CH₃OH are x and y respectively, then
which relation is correct?                                 

1. x>y         

2. x<y         

3. x=y           

4. x$⩾$y

What is the resulting change in the internal energy of the system when 50 calories are added to
the system and the system does work of 30 calories on the surroundings?

1. 20 cal                             
2. 50 cal
3. 40 cal                             
4. 30 cal

Which statements are correct?

1. $2.303 \log \frac{{\mathrm{P}}_2}{{\mathrm{P}}_1}=\frac{∆{\mathrm{H}}_{\mathrm{vap}.}}{\mathrm{R}}\frac{\left[{\mathrm{T}}_2-{\mathrm{T}}_1\right]}{{\mathrm{T}}_1{\mathrm{T}}_2}$ is called Clausius-Clapeyron equation

2. $\frac{∆{\mathrm{H}}_{\mathrm{vap}.}}{\mathrm{Boiling} \mathrm{Point}}=88 J mo{l}^{-1}{K}^{-1}$ is called Trouton's rule

3. Entropy is a measure of unavailable energy, i.e.,

     unavailable energy = entropy x temperature

4. All of the above

The reaction CH₄(g) + Cl₂(g)$\to$CH₃Cl(g) + HCl(g)

has $∆\mathrm{H}$=-25 Kcal

From the given data, what is the bond enthalpy of Cl-Cl bond?

1. 70 Kcal 

2.  80 Kcal

3.  67.75 Kcal

4. 57.85 Kcal