(c) Let the oxidation state of sulphur in ${Na}_{2}S_{4}O_{6}$ is $x.$ ${Na}_{2}S_{4}O_{6}$ 1$\times 2 + 4 \times x + ( - 2) \times 6 = 0$ $2 + 4x - 12 = 0$ $4x - 10 = 0$ $4x = 10$ $x = \frac{10}{4} = 2.5$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.