1. Which one is correctly matched?
- 1) Acids - pH range 8-9
- 2) Acids - pH range 7 (neutral)
- 3) Acids - pH range below 7
- 4) Acids - pH range above7
Answer: 3)
Explanation: Acids have a pH range less than 7, Water is the only solvent that has a pH of 7 (neutral).
2. A Strong acid is same as concentrated acid. State true or false
Answer: 2)
Explanation: Concentration of an acid depends upon the water content whereas the strength of an acid depends on dissociation power.
3. When an acid reacts with a metal, which one of the following gas is usually liberated?
- 1) Hydrogen gas
- 2) Oxygen
- 3) Chlorine
- 4) Ammonia gas
Answer: 1)
Explanation: When metal reacts with acid, a soap bubble is formed and the bubble contains Hydrogen gas (example: HCl, H₂SO₄).
4. Select the one which is wrongly mapped
- 1) Sodium hydroxide - caustic soda
- 2) Calcium carbonate - slaked lime
- 3) Sodium chloride - common salt
- 4) Sodium carbonate - Washing soda
Answer: 2)
Explanation: Calcium hydroxide is commonly referred as slaked lime.
5. What will be the X in the following equation?
MgO + 2HCl ⟶ X + H₂O
- 1) MgCl₂
- 2) MgCl
- 3) 2MgCl
- 4) Mg₂Cl
Answer: 1)
Explanation: MgCl₂ is the product formed when magnesium oxide reacts with hydrochloric acid and water is formed as a by-product.
6. Select the one which is neither an acid nor base
- 1) CH₃OH
- 2) KCl
- 3) HCl
- 4) CH₃COOH
Answer: 2)
Explanation: CH₃COOH and CH₃OH are organic acids, HCl is strong acid and KCl is a salt.
7. Which one will change from red litmus to blue?
- 1) LiOH
- 2) KOH
- 3) HCl
- 4) NaCl
Answer: 3)
Explanation: Since HCl is a base it turns red litmus to blue.
8. What is the pH of 0.0001 molar HCl solution?
Answer: 1)
Explanation: It has a H+ concentration of 10⁻⁴. The value of negative exponent(^-4) gives pH value to be 4.
9. What will be the product when HNO₃ reacts with NH₄OH ?
- 1) NH₂NO₃
- 2) NH₄ (NO₃)₂
- 3) 2NH₄ NO₃
- 4) NH₄ NO₃
Answer: 4)
Explanation: The reaction takes place as follows:
HNO₃ + NH₄OH ⟶ NH₄ NO₃ + H₂O.
10. Find the odd one out:
- 1) Nonhydrated salt: KNO₃
- 2) Acid salt : CuSO₄.5H₂O
- 3) Basic salt: CuCO₃.Cu(OH)₂
- 4) Neutral salt : NaCl
Answer: 2)
Explanation: CuSO₄.5H₂O is a hydrated salt. An example of acid salt is NaHCO₃.
