Class 11th

This is a multiple choice answer as classified in NCERT Exemplar

Option (i), (ii) and (iii)

Ionic hydrides are crystalline, non-volatile and non-conducting in solid state

This is a multiple choice answer as classified in NCERT Exemplar

Option (i) and (iv)

All elements in group 13 are Lewis acids because they form electron-deficient compounds. Excess electrons are found as lone pairs in electron-rich hydrides.

These compounds are made up of elements from groups 15-17. (NH₃ has one lone pair, H₂O has two, and HF has three.) As a result, they act as Lewis bases.

This is a multiple choice answer as classified in NCERT Exemplar

Option (ii) and (iii)

Electron precise hydrides have the required number of electrons to write their conventional Lewis structures. All elements of group 14 form such compounds (e.g., CH₄) which are tetrahedral in geometry.

This is a multiple choice answer as classified in NCERT Exemplar

Option (i) and (ii)

Presence of calcium and magnesium salts in the form of hydrogen carbonate, chloride and sulphate in water makes water 'hard'.

This is a multiple choice answer as classified in NCERT Exemplar

Option (iii) and (iv)

The presence of extensive hydrogen bonding between water molecules gives it remarkable features in the condensed phase (liquid and solid phases). In comparison to H₂S and H₂Se, this results in a high freezing point, high boiling point, high heat of vaporisation, and high heat of fusion.

This is a multiple choice answer as classified in NCERT Exemplar

Option (i) and (ii)

When an electron is removed from a hydrogen atom, the nucleus decreases to 1.5 * 10^-3 pm in size. When compared to usual atomic and ionic sizes of 50 to 200 pm, this is exceedingly small. As a result, H+ does not exist independently and is always bound to other atoms or molecules.

This is a multiple choice answer as classified in NCERT Exemplar

Option (i) and (iii)

Heavy water is utilised as a moderator in nuclear reactors and exchange reactions, and it is more associated with water due to its higher mass.

This is a multiple choice answer as classified in NCERT Exemplar

Option (i) and (ii)

The combination of CO and H₂ is known as water gas. This mixture of CO and H₂ is also known as synthesis gas or 'syngas' since it is used to make methanol and other hydrocarbons.

This is a multiple choice answer as classified in NCERT Exemplar

Option (iii) and (iv)

H⁺ does not exist freely and is always associated with other atoms or molecules. It has an extremely high ionisation enthalpy and does not have metallic properties under normal conditions, unlike alkali metals.

This is a multiple choice answer as classified in NCERT Exemplar

Option (i)

Group 6

From group 6, only chromium forms CrH.