The chemical used as a fixer/developer in photography is

• Sodium sulphate

• Sodium sulphide

• Sodium thiosulphate

• Sodium sulphite

Washing Soda is the common name for

• Calcium Carbonate

• Magnesium Carbonate

• Sodium Carbonate

• Potassium Carbonate

Permanent hardness of water is due to the presence of

• sulphates of sodium and potassium

• sulphates of magnesium and calcium

• carbonates of sodium and magnesium

• bicarbonates of magnesium and calcium

In the reaction ZnO + C → Zn + CO, 'C' acts as

• an acid

• a base

• an oxidising agent

• a reducing agent

Consider the following reaction:

CH₄(g) + H₂O(g) $\stackrel{1270 K}{\to }$ CO(g) + 3H₂(g)

In the reaction given above, the mixture of CO and H₂ is:

• natural gas

• water gas

• producer gas

• industrial gas

126.

Ammonia (NH₃) obtained from differentsources always has same proportion of Nitrogen and Hydrogen. It proves the validity of law of:

• Reciprocal proportion

• Constant proportion

• Multiple proportions

• None of the above

Boric acid is an acid because its molecule:

• accepts OH from water releasing proton

• combines with proton from water molecule

• contains replaceable H⁺ ion

• gives up a proton

The main constituent of Vinegar is:

• Acetic acid

• Ascorbic acid

• Citric acid

• Tartaric acid

White Phosphorus glows in the dark due to:

• amorphous character

• slow oxidation

• high ignition temperature

• good conducting property of electricity

Graphite is a much better conductor of heat and electricity than diamond. This is due to the fact that each carbon atom in graphite:

• undergoes sp² hybridization and forms three sigma bonds with three neighbouring carbon atoms

• undergoes sp³ hybridization

• is tetrahedrally bonded

• is free from van der Waals force