Ncert Solutions Chemistry Class 11th

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans: According to Le Chatelier's principle, when we raise the temperature, it shifts the equilibrium to left and decreases the equilibrium concentration of ammonia since it is an exothermic reaction. In other words, low temperature and high pressure is favourable for high yield of ammonia. There will be no change in equilibria on addition of argon (Ar).

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans: The values of K_c and Q_c are itself sufficient to explain the direction of reaction and less than or greater than one another decides the direction in which reaction will proceed as follows-

(i) As Qc < Kc, the reaction proceeds in the forward direction. 

(ii) If Qc > Kc, the reaction will proceed in the direction of reactants (reverse reaction). 

(iii) If Qc = Kc, no net reaction occurs.

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

D₂O can be prepared by prolonged electrolysis of water. Due to high molecular mass D₂O differs from water.

NaOH+D₂O → NaOD+HOD

HCl+D₂O → DCl+ HOD

NH₄Cl+D₂O → NH₃DCl+HOD

Physical Properties of H₂O and D₂O

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

Atomic hydrogen is highly reactive, whereas molecular hydrogen is rather inert. Bond dissociation enthalpy determines the chemical behaviour of dihydrogen (and, for that matter, any molecule) to a great extent. For a single bond between two atoms of any element, the H-H bond dissociation enthalpy is the highest. As a result, molecular hydrogen reacts only with a few elements.

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

Atomic hydrogen is highly reactive, whereas molecular hydrogen is rather inert. Bond dissociation enthalpy determines the chemical behaviour of dihydrogen (and, for that matter, any molecule) to a great extent. For a single bond between two atoms of any element, the H-H bond dissociation enthalpy is the highest. As a result, molecular hydrogen reacts only with a few elements.

This is a Assertion Type Questions as classified in NCERT Exemplar

Ans: Option (iv)

Both the statements given in the assertion and reason are false.

The energy required to break the first O-H bond is not same than that of the second O-H bond in water molecule, that means the bond enthalpies of the two O-Hare different. This is because the electronic environment around the oxygen atom in water molecules is not the same even after the O-H bond breaks.

This is a Assertion Type Questions as classified in NCERT Exemplar

Ans: Option (i) 

Both the statements given in assertion and reason are correct and the reason given is the correct explanation for the assertion. The sodium chloride formed by the action of chlorine gas on the sodium metal has a complete octet. The valence shells of both the atoms are fulfilled, that is why attains an octet.