Thermodynamics ...

$$H^{+}(aq) + NaOH (aq) \to Na^{+} + H_{2}O(l)\ \triangle H_{1} = -1390\ cals$$
$$HCN(aq) + NaOH(aq) \rightarrow Na^{+} + CN^- + H_{2}O(l)\ \triangle H_{2} = -2900\ cals$$.

A vessel contains $$100$$ litres of a liquid X. Heat is supplied to the liquid in such a fashion that, heat given equals change in enthalpy. The volume of the liquid increases by $$2$$ litres. If the external pressure is one atm, and $$202.6$$ Joules of heat were supplied, then $$[$$U $$-$$ total internal energy$$]$$ :

Calculate the heat needed to raise the temperature of $$20\ g$$ iron from $$25^{\circ}C$$ to $$500^{\circ}C$$, if specific heat capacity of iron is $$0.45\ JK^{-1}g^{-1}$$.

$$H_2(g) + Cl_2 (g)  = 2HCl (g)$$;
$$\Delta{H}$$(298K) $$= -22.06 $$kcal. For this reaction, $$\Delta{U}$$ is equal to:

$$9.2g$$ of toulene $${C}_{2}{H}_{8}(l)$$ is completely burnt in air. The difference in heat change at constant pressure and constant volume at $${27}^{o}C$$ is

Ethyl chloride $$\left( { C }_{ 2 }{ H }_{ 5 }Cl \right) $$, is prepared by reaction of ethylene with hydrogen chloride :

For a certain reaction the change in enthalpy and change in entropy are 40.63 kJ $$mol^{-1}$$ and 100 $$JK^{-1}$$. What is the value of $$\Delta$$ at $$27^0C$$ and indicate whether the reaction is spontaneous or not

In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidizer. The reaction is $$CH_{3}OH_{(l)} + \dfrac {3}{2}O_{2}(g) \rightarrow CO_{2}(g) + 2H_{2}O(l)$$ At $$298\ K$$ standard Gibb's energies of formation for $$CH_{3}OH(l), H_{2}O(l)$$ and $$CO_{2}(g)$$ are $$-166.2, -237.2$$ and $$-394.4\ kJ\ mol^{-1}$$ respectively. If standard enthalpy of combustion of methanol is $$-726\ kJ\ mol^{-1}$$, efficiency of the fuel cell will be

For Pt, $${H}_{2}$$($${p}_{1}atm$$) $$\left| { H }^{ \oplus}\left( 1M \right)  \right| { H }_{ 2 }\left( { p }_{ 2 }\ atm \right)$$ , Pt (where, $${p}_{1}$$ and $${p}_{2}$$ are pressures) cell reaction will be spontaneous if?

What is free energy change $$\left( \Delta G \right) $$ when $$1.0$$ mole of water at $${ 100 }^{ o }C$$ and $$1$$ atm pressure is converted into steam at $${ 100 }^{ o }C$$ and $$2\ atm$$ pressure?