Chemistry

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans:, option (i), (iii) and (iv)

As, K increases with increase in temperature. K increases, it shows that the reaction must be endothermic. No. of molecules increases thus, there is increase in entropy.

This is a short answer type question as classified in NCERT Exemplar

Because of hydrogen bonding HF is liquid whereas HCl is gas as there is lack of hydrogen bonding in HCl.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (iv) 

Since in all the given reaction, the volume is to be kept constant and an inert gas argon is added which will do not take part in reaction. So, the equilibrium will remain unaffected in all the given cases.

This is a short answer type question as classified in NCERT Exemplar

Dihydrogen reacts with dioxygen to form water. The reaction is highly exothermic.

H₂ (g) + O₂ (g) → H₂O (l)

? H = -285.9KJmol^-1

The isotope of hydrogen which has one proton and one neutron is deuterium. When it reacts with O₂ it forms Deuterium oxide (D₂O). Deuterium reacts in a similar way but the reactivity will be lesser than hydrogen because of high bond dissociation enthalpy of D₂ as compared to hydrogen.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (i) 

If the equation is multiplied by 2, the equilibrium constant for the new equation is the square of K it means we must do the square of 5 that is 25. Then and on reversing the reaction the value of the equilibrium constant is inversed means the value of K comes out to be 1/25= 0.04. 

This is a short answer type question as classified in NCERT Exemplar

D₂O has greater intermolecular force of attraction. This is because D₂O exhibits higher values for melting point, enthalpy of vaporization, and viscosity compared to H₂O, indicating stronger intermolecular interactions needed to overcome these properties. 

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (ii)

 Greater the boiling point, lower will be the vapour pressure.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Option(i)

The given reaction is :-

N₂ (g) + 3H₂ (g) ?2NH₃ (g)

A/C to vart Hoff's eqn,

$\frac{\mathrm{d}\mathrm{l}\mathrm{n}\mathrm{K}}{\mathrm{d}\mathrm{T}\mathrm{}}\mathrm{}$ = $\frac{?\mathrm{M}}{\mathrm{R}\mathrm{T}2}$

K is dependent on temperature. As temperature remains constant at equilibrium, so K will remain constant in the given conditions.

This is a short answer type question as classified in NCERT Exemplar

In H₂O₂ oxygen is in -1 oxidation state which has tendency to become -2 that is why it is a better oxidising agent than water.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Option(i)

When the reaction is half completed, [A] = [B].
Thus, [B][A]=1
?G⁰=−RTInK=−RTIn(1)=0