Question

Which of the following statements are correct?

• A. The crystal lattice of ice is mostly formed by covalent as well as hydrogen bonds.
• B. The density of water increases when heated from to due to the change in the structure of the cluster of water molecules
• C. Above the thermal agitation of water molecules increases. Therefore, intermolecular distance increases and water starts expanding.
• D. The density of water increases from to a maximum at because the entropy of the system increases.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A

The crystal lattice of ice is mostly formed by covalent as well as hydrogen bonds.

B

The density of water increases when heated from to due to the change in the structure of the cluster of water molecules

C

Above the thermal agitation of water molecules increases. Therefore, intermolecular distance increases and water starts expanding.

D

The density of water increases from to a maximum at because the entropy of the system increases.

Ice is formed by ordered arrangement of $H_{2}O$ molecules. H is bonded to O by covalent bond.

Each water molecule bonds to 4 other $H_{2}O$ molecules via H-bonding. Thus, option A

Because of rigid packing of $H_{2}O$ molecules in ice, $O^{o}C$ is less denser than water.

Once, it is broken by supply of heat, water molecules come closer to each other and density increases till $4^{o}C$.

Beyond $4^{o}C$, because of higher kinetic energy provided by heat, water molecules move away from each other. Thus, density decreases.