Chemistry QUIZ

Which one of the following does not form an acidic salt?

• Phosphoric acid

• Carbonic acid

• Hydrochloric acid

• Sulphuric acid

Answer explanation

The correct option is B or Carbonic acid. Carbonic acid, with the chemical formula H₂CO₃, is a carbon-containing compound. This compound is found in small amounts of carbon dioxide solutions in water. As it is a weak acid, it doesn't form acidic salts.

An aqueous solution of Copper sulphate solution shows an acidic character, what does it mean?

• It undergoes Photolysis

• It undergoes Dialysis

• It undergoes Electrolysis

• It undergoes Hydrolysis

Answer explanation

copper sulfate is acidified because Copper sulphate is a salt of a strong acid, H2SO4, and a weak base,Cu(OH)2. Copper sulphate hydrolyse in water to give cupric hydroxide which is weak base and sulphuric acid which is strong acid. CuSO4 + 2 H2O = Cu(OH)2 + H2SO4.

Lime water is?

• CaO

• Ca(OH)2

• CaCo3

• CaCl2

Answer explanation

Limewater is a saturated aqueous solution of calcium hydroxide. Calcium hydroxide, Ca(OH)₂, is sparsely soluble at room temperature in water (1.5 g/L at 25 °C). "Pure" (i.e. less than or fully saturated) limewater is clear and colorless, with a slight earthy smell and an astringent/bitter taste.

The Ph of a solution of HCl is 4. This shows that the molarity of the solution is?

• 0.4M

• 0.2M

• 4.0M

• 0.001M

Answer explanation

[H+]=10−pH=10−4molL−1.
Thus molarity is 10−4 or 0.001.

What is Neela Thotha that refers to?

• Potassium Chloride

• Copper Sulphate

• Hydrochloric acid

• Sodium Hydroxide

Answer explanation

Neela Thotha (Copper sulphate) is a mineral origin drug in Unani system of medicine (USM). Chemically, it is known as copper sulphate that formulated as CuSO_4. It is used by various Unani scholars to manage different ailments in effective and safe manner as Mufrad (single) and Murakkab (compound) form viz.

Which of the following were used to develop photographic plates?

• Silver Iodide

• Sodium Thiosulphate

• Hydrochloric acid

• Bromine

Answer explanation

Sodium Thiosulphate is mostly used as a fixer in photography because of its ability to complex nature.

When an acid reacts with metal which one of the following gas is usually liberated?

• Ammonia gas

• Chlorine gas

• Oxygen gas

• Hydrogen gas

Answer explanation

When an acid reacts with a metal, it forms a salt. Hydrogen which is in all the acids gets displaced and liberated as hydrogen gas.

Which one of the following is the correct classification of Dolomite?

• An acid salt

• A mixed salt

• A normal salt

• A double salt

Answer explanation

A double salt is a crystalline salt with the content of a mixture of two simple salts but a distinct crystal structure. Dolomite is a double salt consisting of calcium carbonate (CaCO₃) and magnesium carbonate (MgCO₃) salts.

Which one of the following phenomena occur, when a small amount of acid is added to water?

• Ionisation and Dilution

• Neutralisation

• Dilution

• Endothermic Reaction

Answer explanation

The correct answer is Both ionisation and Dilution. Both the phenomenon of ionisation and Dilution occurs when a small amount of acid is added to water. When an acid is diluted with water, the concentration of H⁺ ions decreases

What happen when an acid react with metal oxide?

• Salt and water is formed

• Metal hydride is formed

• Oxyacid will be formed

• None of the above

Answer explanation

Since the product of reactions of metal oxide with water is basic hydroxide, the metal oxide is also known as basic oxide. Hence their reaction with acid is like a typical acid-base reaction and forms salt and water. Hence the reaction between an acid and metal oxide is a neutralisation reaction.