Ncert Solutions Chemistry Class 11th

This is a  Short Answers Type Questions as classified in NCERT Exemplar

Rainwater has a pH of 5.6 due to the presence of H+ ions formed by the reaction of rainwater with carbon dioxide present in the atmosphere. The reaction can be shown as-

H₂O (l)+CO₂ (g)→H₂CO₃ (aq)

H₂CO₃ (aq)→H+ (aq)+HCO₃⁻ (aq)

This is a  Short Answers Type Questions as classified in NCERT Exemplar

Apart from carbon dioxide gas other greenhouse gases are methane, water vapour, oxides of sulphur, nitrous oxide, CFCs, and ozone. Methane is found to be produced naturally when vegetation is burnt, digested, or rotted in th

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

Tetrachloroethene (Cl₂C=CCl₂ )was earlier used as solvent for dry cleaning. This compound contaminates the groundwater and is also suspected carcinogen. The process using this compound is now being replaced by a process where

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

Pesticides can be defined as the synthetic toxic chemicals  which are meant to kill pests. Most of the organic toxins are water insoluble and non- biodegradable in nature. These high persistent toxins are transferred from lowe

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

Since the earth's surface is heated by the sunlight, it radiates a part of this energy back to the space as longer Infrared wavelengths and some of the heat gets trapped by CFCs and water vapours present in the atmosphere. They abs

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

CO₂ gas is confined to the troposphere only and it forms nearly 0.03 per cent by volume of the atmosphere. With the increased use of fossil fuels, a large amount of carbon dioxide gets released into the atmosphere. Excess of carbon

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

(i) Many techniques are used to control or reduce the formation of photochemical smog. 

(1) If we control the primary precursors of photochemical smog, such as nitrogen dioxide and hydrocarbons, the secondary precursors

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Option (ii) is the correct answer.

A redox couple is defined as pair of compounds or elements having together the oxidised and reduced forms of it and taking part in an oxidation or reduction half reaction.

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Option (i) is the correct answer.

Here the oxygen of peroxide, which is present in -1 state, is converted to zero oxidation state in O₂ undergoing oxidation and decreases to -2 oxidation state in H₂O undergoing reduction

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Option (iii) is the correct answer

As permanganate ion changes to MnO₂