Washing Soda is essentially Sodium Carbonate, a sodium salt of carbonic acid (soluble in water). The molecular formula of washing soda is Na₂CO₃.10H₂O. It is used as an agent to soften hard water. It reacts with the calcium and magnesium bonds present in the water, enabling the detergent to work.

Correct Option: C

Washing Soda is essentially Sodium Carbonate, a sodium salt of carbonic acid (soluble in water). The molecular formula of washing soda is Na₂CO₃.10H₂O. It is used as an agent to soften hard water. It reacts with the calcium and magnesium bonds present in the water, enabling the detergent to work.

A pH meter is an electronic device used for measuring the pH (acidity or alkalinity) of a liquid. A typical pH meter consists of a special measuring probe (a glass electrode) connected to an electronic meter that measures and displays the pH reading.

Correct Option: A

A pH meter is an electronic device used for measuring the pH (acidity or alkalinity) of a liquid. A typical pH meter consists of a special measuring probe (a glass electrode) connected to an electronic meter that measures and displays the pH reading.

Plaster of Paris is the common name of Calcium Sulphate hemihydrate, with chemical formula: CaSO_4.1/2H₂O. Plaster of Paris is produced by heating gypsum to about 150°C.

Correct Option: B

Plaster of Paris is the common name of Calcium Sulphate hemihydrate, with chemical formula: CaSO_4.1/2H₂O. Plaster of Paris is produced by heating gypsum to about 150°C.

Light water (ordinary water) is used as the moderator in U.S. reactors as well as the cooling agent. It acts as the means by which heat is removed to produce steam for turning the turbines of the electric generators.

Correct Option: C

Light water (ordinary water) is used as the moderator in U.S. reactors as well as the cooling agent. It acts as the means by which heat is removed to produce steam for turning the turbines of the electric generators.

Galena is the most abundant lead mineral. It is a metallic, lead-gray mineral with cubic cleavage and a distinctly high density. It belongs to the octahedral sulfide group of minerals with metal ions in octahedral positions.

Correct Option: D

Galena is the most abundant lead mineral. It is a metallic, lead-gray mineral with cubic cleavage and a distinctly high density. It belongs to the octahedral sulfide group of minerals with metal ions in octahedral positions.