5 moles of an ideal gas expands isothermally and irreversibly from a pressure of 10 atm to 1 atm against a constant external pressure of 1 atm. find the W_irr at 300 K:-

1. -15.921 kJ

2. -11.224 kJ

3. -110.83 kJ

4. None of these

In the reaction at 300 K

H₂(g) + Cl₂(g)$\to$2HCl(g)       $∆\mathrm{H}°$= -185 kJ

if 2 mol of H₂ completely react with 2 mole of Cl₂ to form HCl. What is $∆\mathrm{U}°$ for this reaction?

(1) 0

(2) -185 kJ

(3) -370 kJ

(4) None of these

Which of the following reactions has/have a positive \(\Delta S\) (entropy change)?

(i) Ag⁺ (aq) + Cl^-(aq) $\to$AgCl(s)

(ii) NH₄Cl(g) $\to$NH₃(g) + HCl(g)

(iii) 2NH₃(g)$\to$N₂(g) + 3H₂(g)

1. (i) & (ii)

2. (iii)

3. (ii) & (iii)

4. (ii)

When two moles of an ideal gas (Cp, m=$\frac{5}{2}$R) heated from 300 K to 600 K at constant pressure the change in entropy of gas ($∆\mathrm{S}$) is:-

(1) $\frac{3}{2}$Rln2

(2) -$\frac{3}{2}$Rln2

(3) 7R ln 2

(4) 5 Rln2

The free energy change $∆\mathrm{G}$=0 when:-

(1) The system is at equilibrium

(2) Catalyst is added

(3) Reactants are initially mixed throughly

(4) The reactants are completely consumed

For isothermal expanison in case of an ideal gas:-

(1) $∆$G=$∆$S

(2) $∆$G=$∆$H

(3) $∆$G=-T$∆$S

(4) None of these

At 25$°$C, for the process H₂O(l)$\rightleftharpoons$H₂O(g);

$∆\mathrm{G}°$ is 8.6 kJ. The vapour pressure of water at this temperature is nearly:

1. 24 torr

2. 285 torr

3. 32.17 torr

4. 100 torr

What will be the standard enthalpy of reaction for the following reaction using the listed enthalpies of reaction?

3Co(s) + 2O₂(g)$\to$Co₃O₄(s);       $∆\mathrm{H}$=?

2Co(s) + O₂(g) $\to$2CoO(s)          $∆{\mathrm{H}}_1$= -475.8 KJ

6CoO(s) + O₂(g) $\to$2Co₃O₄(s)    $∆{\mathrm{H}}_2$ = -355.0 KJ

1. -891.2 KJ

2. -120.8 KJ

3. 891.2 KJ

4. -830.8 KJ

For given following equations and $∆\mathrm{H}°$ values, determine the enthalpy of reaction at 298 K for the reaction:

C₂H₄(g) + 6F₂(g) $\to$ 2CF₄(g) + 4HF(g)

Given:
H₂(g) + F₂(g) $\to$ 2HF(g)       $∆{\mathrm{H}}_1^{°}$= -537 kJ

C(s) + 2F₂(g) $\to$CF₄(g)         $∆{\mathrm{H}}_2^{°}$=-680 kJ

2C(s) + 2H₂(g) $\to$C₂H₄(g)    $∆{\mathrm{H}}_3^{°}$= 52 kJ

1. -1165 

2. -2486

3. +1165

4. +2486

If $∆{\mathrm{H}}_{\mathrm{f}}^{°}$(C₂H₄) and $∆{\mathrm{H}}_{\mathrm{f}}^{°}$(C₂H₆) are x₁ and x₂ kcal/mol then heat of hydrogenation of C₂H₄ is :-

(1) x₁ + x₂

(2) x₁ - x₂

(3) x₂ - x₁

(4) x₁ + 2x₂