The internal energy change when a system goes from state A to B is 40 kJ/mol. If the system goes from A to B by a reversible path and returns to state A by an irreversible path. What would be the change in internal energy?

Change in entropy is negative for:

The mathematical form of the first law of thermodynamics when heat (q) is supplied and W is work done by the system (-ve) is:

Which statements are correct?

     unavailable energy = entropy x temperature

$∆\mathrm{S}°$ will be highest for the reaction:

One mole of ice is converted into the water at 273 K. The entropies of H₂O(s) and H₂O(l) are 38.20 and 60.01 J mol^-1K^-1 respectively. The enthalpy change for the conversion is:

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

has $∆\mathrm{H}$=-25 K cal

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

Entropy decreases in which of the following reactions?

Heat of the neutralization is greater than 13.7 kcal in -

Consider the reaction

N₂(g) + 3H₂(g)$\to$2NH₃(g) carried out at constant temperature and pressure. If $∆$H and $∆$E are enthalpy change and internal energy change respectively, which of the following expression is True?

$$\begin{gathered} 1. ∆\mathrm{H}⩾∆\mathrm{E} \\ 2. ∆\mathrm{H}=∆\mathrm{E} \\ 3. ∆\mathrm{H}<∆\mathrm{E} \\ 4. ∆\mathrm{H}>∆\mathrm{E} \end{gathered}$$

Work done is maximum in -

For exothermic reaction to be spontaneous ($∆\mathrm{S}$=negative) temperature must be -

Which of the following conditions should be satisfied for the given reaction to be spontaneous at 0$°$C and 1 atm?

H₂O(s) $\rightleftharpoons$H₂O(l)

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

An ideal gas expands at a constant external pressure of 2.0 atmosphere by 20 litre and absorbs 10kJ of heat from surrounding. What is the change in internal energy of the system:-

36 ml of pure water takes 100 sec to evaporate from a vessel and heater connected to an electric source which delivers 806 watt. The $∆{\mathrm{H}}_{\mathrm{vaporisation}}$ of H₂O is:-

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:-

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?

Predict which of the following reaction(s) has a positive 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)

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:-

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

For isothermal expanison in case of an ideal gas:-

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:-

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

The standard enthalpy of vaporisation $∆$_vapH$°$ for water at 100$°$C is 40.66 kJ mol^-1. The

internal energy of vaporisation of water at 100$°$C (in kJ mol^-1) is- 

(Assume water vapour to behave like an ideal gas)

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)

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

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 :-

For oxidation of iron, 4Fe(s) + 3O₂(g) $\to$2Fe₂O₃(s), $∆{\mathrm{H}}_{\mathrm{r}}^{°}$=-1648x10³ J mol^-1 and entropy change is -549.4 J k^-1mol^-1 at 298 K:-

The reaction is

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

One mole of methanol when burnt in O₂ gives out 723 kJ mol^-1 heat. If one mole of O₂ is used, what will be the amount of heat evolved?