Free Anomalous Behaviour of Water MCQs with Answers

• A. loses one of its hydrogen atoms
• B. is hydrogen bonded to four others in an open tetrahedral arrangement
• C. moves faster than in the liquid
• D. is compressed closer to its neighbours

Explanation: Every molecule uses its two hydrogens and its two lone pairs, so a rigid open cage with large empty spaces is formed, and this occupies…

• A. 0 degrees Celsius
• B. 100 degrees Celsius
• C. 4 degrees Celsius
• D. minus 4 degrees Celsius

Explanation: Cooling water from room temperature increases density as normal, but below 4 degrees the open hydrogen bonded structure begins to form and…

• A. it is a very light molecule
• B. it is a good electrical conductor
• C. a large amount of energy is used breaking hydrogen bonds before the temperature rises
• D. it has a low boiling point

Explanation: Much of the heat supplied goes into breaking hydrogen bonds rather than into increasing the kinetic energy of the molecules, so the…

• A. 75%
• B. 81%
• C. 73%
• D. 89%

Explanation: The commonly cited composition for the human brain and heart is about 73% water, so option c matches the stated reference.

• A. Change of bond angles
• B. Cubic structure of ice
• C. Empty space present in the structure of ice
• D. Change of bond length

Explanation: When water freezes, hydrogen bonds arrange its molecules into an open lattice containing empty spaces, so the same mass occupies a larger…

• A. Equal to that of ice
• B. Greater than that of ice
• C. Less than that of ice
• D. All are possible

Explanation: At the same ordinary pressure and near 0°C, liquid water is denser than ice because ice has an open hydrogen-bonded structure with greater…

• A. increases with increasing pressure
• B. decreases with increasing pressure
• C. is independent of pressure
• D. is proportional to pressure

Explanation: Ice, unlike most substances, contracts upon melting. When pressure is applied to ice, it forces the molecules closer together, making it…

• A. -2 °C
• B. -4 °C
• C. None of these
• D. 0 °C

Explanation: Freezing or melting point is defined as the temperature at which the liquid and solid states of a substance are in equilibrium with each…

• A. Ice
• B. Liquid
• C. Vapour
• D. Both ice and liquid

Explanation: 0degree C at 1 atm pressure is the freezing point of pure water where its solid-state and liquid state coesxist in an equilibrium.

• A. Decrease in volume
• B. Decrease in density
• C. Increase in density
• D. Increase in volume

Explanation: Ice is less dense than water. Freezing causes a decrease in density because the water molecules form a more open and less dense structure…

• A. Dipole dipole forces.
• B. Debye forces.
• C. H-bonding.
• D. London dispersion forces.

Explanation: Hydrogen bonding is a type of intermolecular force that occurs between a hydrogen atom bonded to an electronegative atom (such as…

• A. Its structure is similar to diamond
• B. High density
• C. Low density
• D. None

Explanation: Normally, when a substance freezes, it becomes denser. This is because the molecules slow down and pack closer together.

• A. 15
• B. 29
• C. 9
• D. 100

Explanation: The exact amount of volume that ice occupies more than water depends on the temperature and pressure.

• A. Tetrahedral
• B. Octahedral
• C. Cubic
• D. Hexagonal

Explanation: For Fedral Board: The water molecules in ice are arranged in a hexagonal lattice, with each molecule being bonded to four other molecules.

• A. -4 C
• B. - 1 C
• C. 0 C
• D. 4 C

Explanation: As density is inversely proportional to the volume, the density of water increases when the temperature is lowered.

• A. Higher than water
• B. Lower than water
• C. Similar to water
• D. Higher than 1.59/cm3

Explanation: The density of ice is lower than water. The density of water is 1.000 g/cm3 at 0°C, while the density of ice is 0.917 g/cm3 at 0°C.

• A. 273K
• B. 373K
• C. 277K
• D. 509K

Explanation: This is equal to 4 degree celsius mentioned in punjab book page 87 under structure of ice.

• A. 0°C
• B. 2°C
• C. 4°C
• D. 100°C

Explanation: Water has its maximum density at 4°C because hydrogen bonding produces an open structure near freezing, while warming from 0°C to 4°C…

• A. It expands on heating
• B. It contracts on heating
• C. Both
• D. None

Explanation: If we take some water at 0 C and start heating it, we find that in the temperature range 0oC to 4oC, it contracts instead of expanding.on…

• A. 2.98˚C
• B. 3.98 ˚C
• C. 4 ˚C
• D. 4.98 ˚C

Explanation: The maximum density of water is at 4°C as there are two opposite effects that are in balance.