Question

The oxidation number of S in $Na_2S_4O_6$ is

• A. + 2.5 for each S atom
• B. + 2 and + 3 (two S have + 2 and other two have + 3)
• C. + 2 and + 3 (three S have + 2 and one S has + 3)
• D. + 5 and 0 (two S have + 5 and the other two have 0).

Answer 1

Answer: (D)

: The structure of $Na_2S_4O_6$ is The two $S$ atoms which are linked to each other have O.N. of zero. The O.N. of other two $S$- atoms can be calculated as follows : $2x + 2 \times 0 + 6 \times -2 = -2$ or $2 x = 12 — 2 = 10$ or $x = + 5$