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SSC CGL 2024 PYQ — Question 27

SSC CGL - 12 Sep 2024 - Shift 1 • General Awareness • Q27

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 Calculate the oxidation number of ‘S’ in H2S2O7.

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Correct answer: C

Explanation

The correct answer is option 3 i.e. 6.

To calculate the oxidation number of sulfur (S) in H2S2O7​ (disulfur heptoxide), we follow these steps:

  1. The oxidation number of hydrogen (H) is +1, and oxygen (O) is -2.
  2. The molecule is neutral, so the sum of oxidation numbers must equal 0.
  3. Let the oxidation number of sulfur be x. The equation becomes:2

2x+2(1)+7(−2)=0

x = 62x+2−14=0 ⇒ 2x=12 ⇒ x=6

Thus, the oxidation number of sulfur in H2S2O7​​ is 6.