Thermodynamics Test

What is the mole composition of the mixture of oxygen and steam on being passed over coke at 1273K, to keep temperature constant ?

$$C\left( graphite \right) +{ 1 }/{ 2 }{ O }_{ 2 }\left( g \right) \longrightarrow CO\left( g \right) ; \ { \Delta H }/{ kJ }=-110.5kJ$$

$$CO\left( g \right) +{ 1 }/{ 2 }{ O }_{ 2 }\left( g \right) \longrightarrow C{ O }_{ 2 }\left( g \right) ;\ { \Delta H }/{ kJ }=-282.9kJ$$

$${ H }_{ 2 }\left( g \right) +{ 1 }/{ 2 }{ O }_{ 2 }\left( g \right) \longrightarrow { H }_{ 2 }O\left( l \right) ;\ { \Delta H }/{ kJ }=-285.8kJ$$

$$C\left( graphite \right) +2{ H }_{ 2 }\left( g \right) \longrightarrow C{ H }_{ 4 }\left( g \right) ;\ { \Delta H }/{ kJ }=-74.8kJ$$

Determine change in Gibb's energy (in Joule) if entropy of gas $$S = 10 + 10^{2} T (J/K)$$.

$$Br_2(l) + Cl_2(g) \rightarrow 2BrCl(g)$$. For the reaction $$\Delta H^o = 29.3 kJ$$ & the entropies of

$$Br_2(l), Cl_2(g)$$ & BrCl(g) at the $$298 K$$ are $$152.3, 223.0, 239.7$$ $$J mol^{1} K^{1} $$ respectively

Directions For Questions

Chemist seemingly insatiable need to measure heat has led to a broad spectrum of measurement methods. A special calorimeter is the ice calorimeter, in which the heat released in an exothermic reaction is trapped in an ice -water mixture at 273 K, causing ice to melt which result in contraction of volume.

A student employs this method to determine the heat of combustion of methanol. He finds that when a sample of methanol weighing 0.320g is burnt in excess oxygen in an ice calorimeter at constant volume and 273 K, according to the reaction,

$$2CH_{3}OH(l)+3O_{2}(g)\rightarrow 2CO_{2}(g)+4H_{2}O(l)$$

the volume of ice and water surrounding the sample decreased by 1.82 ml.

[Given: specific volume of ice $$=1.091\:ml/gm$$, specific volume of $$H_{2}O(l)=1\:ml/gm,\:\Delta H_{fusion}$$ of ice$$ =340\:J/gm$$ and $$R=8.314\ J/(mol.K)$$].

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