Question

(A) List the properties of water.

(B)Explain the anomalous expansion of water.

Answer 1

(A) Properties of water.

• Pure water is transparent, colourless, odourless and tasteless in nature. But the taste of tap water is due to the presence of dissolved solids and gases.
• Water exists in three different states. The solid form of water is called ice, liquid form is called water, and the gaseous form of water is called steam or water vapour.
• Water is called the universal solvent. It dissolves most of the substances like salt and sugar.
• Many liquids like fruit juice, Alcohol, Acetone, and vinegar are miscible with water.
• Water shows different behaviour when heated or cooled between $4°\mathrm{C}$ and$0°\mathrm{C}$. This property of water is called the anomalous expansion of water.
• Freezing point of pure water is $0°\mathrm{C}$. Water freezes on cooling to $0°\mathrm{C}$ and forms ice.
• Boiling point of water is$100°\mathrm{C}$. Water boils on heating to $100°\mathrm{C}$ , form steam under normal pressure.
• Water is a bad conductor of both heat and electricity.

(B) Anomalous expansion of water.

• During the winter season, when liquid like coconut oil freezes, it changes its state from liquid to solid i.e., volume decreases.
• But in the case of water, there is an opposite behaviour. When water is cooled and frozen to form ice, it expands instead of decreasing the volume.
• In other words, we can say that water expands its volume when it freezes to form ice. This is called the anomalous expansion of water.
• Therefore, ice has a maximum volume than water from which it is formed.
• But when an ice piece is dropped into a beaker containing water, we observe that piece of ice floats on the water even though it has more volume.
• This is happening because the density of ice is less than that of water.

$Density=\frac{Mass}{Volume}$