Chemistry MCQs for NEET — Practice Questions with Answers

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

'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:-

The temperature of an ideal gas expansion increases in an:-

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:-