Question

The oxidation number of sulphur is $-4$ in

• A. $H_{2}S$
• B. $CS_{2}$
• C. $Na_{2}SO_{4}$
• D. $Na_{2}SO_{3}$

Answer 1

Answer: (A), (B), (C), (D)

The oxidation number of S in given compounds are as follows :
$(i) H_{2}S$
Let the oxidation state of S be $x$
$\therefore 2 + x = 0$
$x = - 2$
$(ii) CS_{2}$
$4 + 2x= 0\Rightarrow x = - 2$
$(iii) Na_{2}SO_{4}$
$2(+1) + x + 4(-2) = 0$
$2 + x - 8 = 0$
$x = + 6$
$(iv) Na_{2}SO_{3}$
$2(+1) + x + 3(-2) = 0$
$2 + x - 6 = 0$
$x = + 4$