Second Chapter Solved Exercise MCQs Of FSC Second Year Chemistry
written by Almas AnwarThe Second Chapter Solved Exercise MCQs of FSC 2nd-year Chemistry provides a complete set of solved multiple-choice questions (MCQs). Each MCQ comes with a brief explanation to help you understand the correct answer. These solutions are designed to support students in preparing for their exams, making complex concepts easier to grasp and ensuring a solid foundation for success.”
Second chapter solved MCQs with explanation
1.Which one of the following does not belong to alkaline earth metals?
(a) Be
(b) Ra
(c) Ba
(d) Rn
Explanation: Option (d) is correct. Because: Be (Beryllium), Ra (Radium), and Ba (Barium) are all alkaline earth metals, which are in Group 2 of the periodic table. Rn (Radon) is a noble gas, located in Group 18. It does not belong to the alkaline earth metals group.
2. The oxide of beryllium is:
(a) acidic
(b) basic
(c) amphoteric
(d) none of these
Explanation: Option (c) is correct. Because Beryllium oxide (BeO) is considered amphoteric because it can react both as an acid and as a base. It can react with acids to form beryllium salts and with strong bases to form beryllates. This dual behavior is characteristic of amphoteric oxides.
3. Which ion will have the maximum value of heat of hydration?
(a) Na⁺
(b) Cs²⁺
(c) Ba²⁺
(d) Mg²⁺
Explanation: Option (d) is correct. Because the heat of hydration depends on two main factors: the charge density of the ion and its size. The higher the charge density (charge/size ratio), the greater the heat of hydration.
- Mg²⁺ has a high charge density because it has a +2 charge and a relatively small ionic radius.
- Na⁺ has a lower charge density due to its smaller charge and larger size compared to Mg²⁺.
- Cs²⁺ is incorrectly listed as it should be Cs⁺, and it has a much larger size and lower charge density.
- Ba²⁺ also has a lower charge density compared to Mg²⁺ because of its larger ionic radius.
Thus, Mg²⁺ has the highest charge density and therefore the maximum heat of hydration among the options.
4. Which of the following sulphates is not soluble in water?
(a) sodium sulphate
(b) potassium sulphate
(c) zinc sulphate
(d) barium sulphate
Explanation: Option (d) is correct. Because Barium sulphate (BaSO₄) has a very low solubility in water due to the strong lattice energy of its crystalline structure, which outweighs the hydration energy.
5. The element caesium bears resemblance with
(a) Ca
(b) Cr
(c) both of these metals
(d) none of these metals
Explanation: Option (d) is correct. Because:
- Caesium (Cs) is in Group 1 of the periodic table, which contains alkali metals.
- Let’s check the options:
- Calcium (Ca) is in Group 2 (alkaline earth metals), not Group 1.
- Chromium (Cr) is a transition metal, and it’s also not in Group 1.
- Saying both would mean Ca and Cr are similar to Cs, but that’s not true.
Since Caesium is an alkali metal and belongs to a different group, it does not resemble either Ca or Cr.
6. Chile saltpetre has the chemical formula:
(a) NaNO₃
(b) KNO₃
(c) Na₂B₄O₇
(d) Na₂CO₃.H₂O
Explanation: Option (a) is correct. Because Chile saltpetre, also known as sodium nitrate, has the chemical formula NaNO₃. It is a naturally occurring mineral used in fertilizers and explosives.
7. The mineral (CaSO₄•2H₂O) has the general name:
(a) gypsum
(b) dolomite
(c) calcite
(d) epsom salt
Explanation: Option (a) is correct. Because CaSO₄•2H₂O is the chemical formula for gypsum, which is a hydrated form of calcium sulfate. The other options are different minerals:
- Dolomite is CaMg(CO₃)₂.
- Calcite is CaCO₃.
- Epsom salt is MgSO₄•7H₂O.
8. Down’s cell is used to prepare:
(a) sodium carbonate
(b) sodium bicarbonate
(c) sodium metal
(d) sodium hydroxide
Explanation: Option (c) is correct. Because Down’s cell is used for the electrolysis of molten sodium chloride (NaCl). In this process, sodium metal is obtained at the cathode, and chlorine gas is produced at the anode. This method is primarily used for producing sodium metal.
9. Which element is deposited at the cathode during the electrolysis of brine in diaphragm cell?
(a) H₂
(b) Na
(c) Cl₂
(d) O₂
Explanation: Option (a) is correct. Because during the electrolysis of brine (a concentrated NaCl solution) in a diaphragm cell, water is reduced at the cathode, producing hydrogen gas (H₂) and hydroxide ions (OH⁻). Sodium (Na) ions remain in the solution, and chlorine (Cl₂) is released at the anode.
