In the reaction, both $∆$H and $∆$S are positive. The condition(s) under which the reaction would not be spontaneous are/is:

1. $∆$H>T$∆$S                             

2. $∆$S=$∆$H/T

3. $∆$H=T$∆$S                               

4. All of the above

'The free energy change due to a reaction is zero when-

1. The reactants are initially mixed.

2.  A catalyst is added

3. The system is at equilibrium

4. The reactants are completely consumed

18 g of ice is converted into water at 0$°$C and 1 atm. The entropy of H₂O_(s) and H₂O_(l) are 38.2 and 60 J K^-1 mol^-1 respectively. the enthalpy for this conversion will be

(1) 5951.4 J/mol

(2) 595.14 J/mol

(3) -595.14 J/mol

(4) None of these

For a given reaction, if ΔH = 35.5 kJ/mol and ΔS = 83.6 J/K·mol, at what temperature is the reaction spontaneous?
(Assume ΔH and ΔS remain constant with temperature.)

The correct thermodynamic conditions for the spontaneous reaction at all temperatures is

$\left(\mathrm{a}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}>0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}<0$
$\left(\mathrm{b}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}<0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}>0$
$\left(\mathrm{c}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}<0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}<0$
$\left(\mathrm{d}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}<0<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>∆\mathrm{S}=0$

For the reaction, X₂O₄(l) $\to$2XO₂(g)

$∆$U = 2.1 kcal, $∆$S = 20 cal K^-1 at 300 K. Hence, $∆$G is

1. 2.7 kcal

2. -2.7 kcal

3. 9.3 kcal

4. -9.3 kcal

The values of $∆$H and $∆$S for the given reaction are 170 kJ and 170 JK^–1, respectively.
\(\mathrm{C} \text { (graphite) }+\mathrm{CO}_2(\mathrm{~g}) \rightarrow 2 \mathrm{CO}(\mathrm{g})\)
This reaction will be spontaneous at:

1. 710 K

2. 910 K

3. 1110 K

4. 510 K

Identify the correct statement for change of Gibbs energy for a system ($∆$G_system) at constant temperature and pressure:

(1) If $∆$G_system > 0, the process is spontaneous

(2) If $∆$G_system = 0, the system has attained equilibrium

(3) If $∆$G_system = 0, the system is still moving in a particular direction

(4) If $∆$G_system < 0, the process is not spontaneous

The enthalpy and entropy change for a chemical reaction are

–2.5 × 10³ cal and 7.4 cal deg^–1 respectively.  Predict the reaction at 298 K is

1. Spontaneous

2. Reversible

3. Irreversible

4. Non-spontaneous

Which of the following is true for the reaction $H_{2}O\left(l\right)\underset{}{\overset{}{\rightleftharpoons }}{H}_{2}O\left(g\right)$ at 100°C and 1 atmosphere

1. ΔE = 0

2. ΔH = 0

3. ΔH = ΔE

4. ΔH = TΔS