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SSC MTS 2024 PYQ — Question 48

SSC MTS - 30/09/2024 - (12:30 PM - 2:30 PM) • General Awareness • Q48

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Select the INCORRECT pair of molecule/formula units and their molar mass from the following.

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Correct answer: D

Explanation

The correct answer is Option  4 i.e. HNO3.

  1. HCl
    H = 1 g/mol
    Cl = 35.5 g/mol
    Total = 1 + 35.5 = 36.5 g/mol ✔️

  2. NaCl
    Na = 23 g/mol
    Cl = 35.5 g/mol
    Total = 23 + 35.5 = 58.5 g/mol ✔️

  3. CH₄ (Methane)
    C = 12 g/mol
    H = 1 g/mol × 4 = 4 g/mol
    Total = 12 + 4 = 16 g/mol ✔️

  4. HNO₃ (Nitric acid)
    H = 1 g/mol
    N = 14 g/mol
    O = 16 g/mol × 3 = 48 g/mol
    Total = 1 + 14 + 48 = 63 g/mol, not 62 g/mol

The incorrect pair is HNO₃ - 62 (should be 63 g/mol).