Free Chemistry in Daily Life MCQs with Answers

151. Chemical formula for Water is _______ ?

• A. NaAlO2
• B. H2O
• C. Al2O3
• D. CaSiO3

Explanation: A water molecule contains two hydrogen atoms bonded to one oxygen atom, giving the formula H₂O. The other formulas represent compounds such as sodium aluminate and aluminium oxide.

152. The PH of milk is __________?

• A. 6.0
• B. 6.5
• C. 7.0
• D. 7.5

Explanation: Fresh milk is mildly acidic, with a pH close to 6.5, mainly because of dissolved salts, proteins, and carbon dioxide. A pH of 7.0 would indicate neutrality rather than normal fresh milk.

153. Turpentine is obtained from___________?

• A. Oak tree
• B. Pine tree
• C. Birch tree
• D. Lemon tree

Explanation: Turpentine is obtained mainly by distilling the resin of pine trees. It is a volatile mixture of terpenes and is used as a solvent and in paints.

154. Soap and detergents remove the dirt from clothes due to__________?

• A. Osmosis
• B. Capillary action
• C. Lowering of interfacial tension
• D. Diffusion

Explanation: Soap and detergents lower the interfacial tension between water, fabric, and oily dirt, allowing water to wet the cloth and surround grease particles. Their molecules then keep the loosened dirt suspended in water.

155. Which of the following is a component of soap?

• A. Sodium sulphate
• B. Sodium stearate
• C. Sodium chloride
• D. Sodium nitrate

Explanation: Sodium stearate is a typical soap, formed from stearic acid and sodium hydroxide. Its long hydrocarbon tail attracts grease while its ionic end interacts with water.

156. The temperature at which two conjugate solutions change into one homogeneous solution is called__________?

• A. Azeotrope
• B. Conjugate temperature
• C. Consolute temperature
• D. Eutectic point

Explanation: The consolute temperature is the temperature at which two conjugate liquid phases become one homogeneous phase. It is also called the critical solution temperature.

157. Which of the following type of Coal, has maximum carbon content?

• A. Peat
• B. Lignite
• C. Anthracite
• D. Bituminious

Explanation: Anthracite is the highest-grade coal and contains the greatest percentage of carbon. Peat, lignite and bituminous coal have progressively lower carbon content.

158. What is the molecular formula for Nitric acid ________ ?

• A. HNO2
• B. HNO3
• C. HN2O2
• D. H2NO4

Explanation: Nitric acid contains one hydrogen, one nitrogen and three oxygen atoms, giving the formula HNO3. HNO2 is nitrous acid, a different nitrogen oxyacid.

159. What is the molecular weight of Ammonia (NH3) ________ ?

• A. 17.031 g/mol
• B. 18.031 g/mol
• C. 19.031 g/mol
• D. 27.033 g/mol

Explanation: Ammonia has one nitrogen atom and three hydrogen atoms, so its molar mass is about 14.01 + 3(1.008) = 17.03 g/mol. Therefore 17.031 g/mol is the matching value.

160. What is the molecular formula for Ammonia?

• A. NH
• B. NH2
• C. NH3
• D. NH4

Explanation: Ammonia consists of one nitrogen atom bonded with three hydrogen atoms, giving the molecular formula NH3. NH4 refers to the ammonium ion only when it carries a positive charge.