For the equilibrium $\mathrm{A}(\mathrm{g})+2 \mathrm{~B}(\mathrm{~g}) \rightleftharpoons \mathrm{AB}_2(\mathrm{~g})$ the value of equilibrium constant at $300 \mathrm{k}$ is $3 \times 10^{-3} \mathrm{~mole}^{-2} \mathrm{~L}^2$ and value of equilibrium constant at $500 \mathrm{k}$ is $5 \times 10^{-5} \mathrm{~mol}^{-2} \mathrm{~L}^2$. What is the sign of enthalpy change for this reaction

Both (a) and (b) are possible at lower temperature it is positive and at high temperature it is negative.

NEET UG CHEMISTRY MCQ: Equilibrium

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Analyzing +4 | -1

For the equilibrium

\mathrm{A}(\mathrm{g})+2 \mathrm{~B}(\mathrm{~g}) \rightleftharpoons \mathrm{AB}_2(\mathrm{~g})

the value of equilibrium constant at

300 \mathrm{k}

3 \times 10^{-3} \mathrm{~mole}^{-2} \mathrm{~L}^2

and value of equilibrium constant at

500 \mathrm{k}

5 \times 10^{-5} \mathrm{~mol}^{-2} \mathrm{~L}^2

.

What is the sign of enthalpy change for this reaction

View answer and explanation

Correct option: B

Negative

Option B (Negative) is correct. Since the equilibrium constant decreases as temperature increases, the reaction is exothermic, indicating a negative enthalpy change.

More Questions from Equilibrium

Practice All Chapter MCQs →

Given below are two statements: One is labelled as Assertion A and the other labelled as Reason R.
Assertion A: During the boiling of water having temporary hardness,

Mg{(HC{O_3})_2}

is converted to

MgC{O_3}

.
Reason R The solubility product of

Mg{(OH)_2}

is greater than that of

MgC{O_3}

.
In the light of the above statements, choose the most appropriate answer from the options given below At a certain temperature,

K_{\mathrm{P}}

for the dissociation of solid

\mathrm{CaCO}_3

4.5 \times 10^{-2}

atm and for the reaction

\mathrm{C}(\mathrm{s})+\mathrm{CO}_2(\mathrm{g}) \rightleftharpoons 2 \mathrm{CO}(\mathrm{g}),

the

K_{\mathrm{P}}

value is

2.0 \mathrm{~atm}.

The pressure of carbon monoxide at this temperature, when solid carbon

\mathrm{CaO}

and

\mathrm{CaCO}_3

are mixed together and allowed to attain equilibrium is Phenolphthalein shows … in acid medium. At the state of dynamic equilibrium, for solute

+

solvent

\leftrightharpoons

solution. For

\mathrm{PC}{\mathrm{l}_5}\leftrightharpoons\mathrm{PC}{\mathrm{l}_3} + \mathrm{C}{\mathrm{l}_2}

, initial concentration of each reactant and product is 1 M. If

{K_{\mathrm{eq}}} = 0.41

then Select the

\mathrm{p}{K_a}

value of the strongest acid from the following