Which one of the following is the chemical formula of Washing Soda?

• NaHCO₃

• Na₂CO₃.10H₂O

• Na₂CO₃.5H₂O

• NaOH

Which one of the following is NOT true for bleaching powder?

• It is used as a reducing agent in chemical industries

• It is used for bleaching wood pulp in paper factories

• It is used for disinfecting drinking water

• It is used for bleaching linen in textile industry

Which one of the following is the number of water molecules that share with two formula unit CaSO₄ in Plaster of Paris?

• One

• Two

• Five

• Ten

How is carbon black obtained?

• By heating wood at high temperature in absence of air

• By heating coal at high temperature in absence of air

• By burning hydrocarbons in a limited supply of air

• By heating coal at high temperature in presence of air

Which one of the following properties is NOT true for graphite?

• Hybridisation of each carbon atom is sp³

• Hybridisation of each carbon atom is sp²

• Electrons are delocalized over the whole sheet of atoms

• Each layer is composed of hexagonal rings

Which one of the following is the purest form of Carbon?

• Charcoal

• Coke

• Fullerene

• Carbon black

47.

The Poisonous nature of Carbon monoxide (CO) is due to its

• Insolubility in water

• Ability to form a complex with haemoglobin.

• Ability to reduce some metal oxides

• Property of having one sigma bond

Which one of the following alkali metals has lowest melting point?

• Sodium

• Potassium

• Rubidium

• Caesium

Which one of the following metals is alloyed with sodium to transfer heat in a nuclear reactor?

• Potassium

• Calcium

• Magnesium

• Strontium

Which one of the following metals is used in the filaments of photoelectric cells that convert light energy into electric energy?

• Tungsten

• Copper

• Rubidium

• Aluminium