For the gas phase reaction, PCl_ 5(g) PCl_ 3(g) + Cl_ 2(g) which … - Vidyadip

MCQ

For the gas phase reaction,

$PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$

which of the following conditions are correct ?

A
$\Delta H < 0$ and $\Delta S < 0$
B
$\Delta H > 0$ and $\Delta S < 0$
C
$\Delta H = 0$ and $\Delta S < 0$
✓
$\Delta H > 0$ and $\Delta S > 0$

✓

Answer

Correct option: D.

$\Delta H > 0$ and $\Delta S > 0$

d
Gas phase reaction

$\mathrm{PCl}_{5(\mathrm{g})}=\mathrm{PCl}_{3(\mathrm{g})}+\mathrm{Cl}_{2(\mathrm{g})}$

$\Delta \mathrm{H}=\Delta \mathrm{E}+\Delta \mathrm{n}_{\mathrm{g}} \mathrm{RT}$

$\Delta n_{g}=$ Change in number of moles of product and reactant species.

since $\Delta n_{g}=+v e,$ hence $\Delta H=+v e$

also one mole of $\mathrm{PCl}_{5}$ is dissociated into two moles of $\mathrm{PCl}_{5}$ and $\mathrm{Cl}_{2}$ in the same phase.

Therefore, $\Delta S=S_{\text {product }}-S_{\text {reactant }}$

$\Delta S=+v e$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 5. Thermodynamics and thermochemistry→5. Thermodynamics and thermochemistry — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Hydrogen bond formation takes place between the hydrogen atom and an atom having high $ .........$

Which one of the following pairs represents the stereoisomerism

Which will have maximum $pH$

The oxide formed by the element on extreme right and in the left of periodic table are generally :

Poisonous gas ‘Lewissite’ is obtained by the reaction of

The oxidation number of chlorine atom in bleaching powder is :

Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species

The geometry of $ClO_3^ - ,$ according to valence shell electron pair repulsion (VSEPR) theory will be

Di-imide $(N_2H_4)$ is used to reduce doubble bond of

Which of the following statement(s) is/are correct in the case of heavy water?