Question

For the reaction, \[\ce{3I^-(aq) + S2O^2-_8(aq) -> I^-_3(aq) + 2SO^2-_4(aq)}\]

`(d[SO_4^(2-)])/dt = 2.2 xx 10^(-2)` M/s at a particular time.

Calculate `(a) -(d[I^-])/dt   (b) -(d[S_2O_8^(2-)])/dt   (c) (d[I_3^-])/dt`

Answer 1

 \[\ce{3I^-(aq) + S2O^2-_8(aq) -> I^-_3(aq) + 2SO^2-_4(aq)}\]

Rate of reaction: `- 1/3  (d[I^-])/dt = (d[S_2O_8^(2-)])/dt = (d[I_3^-])/dt = 1/2  (d[SO_4^(2-)])/dt`

(a) `(-d[I^-])/dt = 3/2  (d[SO_4^(2-)])/dt = 3/2 xx 2.2 xx 10^-2 = 3.3 xx 10^-2  "M/s"`

(b) `-(d[S_2O_8^(2-)])/dt = 1/2  (d[SO_4^(2-)])/dt = 1/2 xx 2.2 xx 10^-2 = 1.1 xx 10^-2  "M/s"`

(c) `(d[I_3^-])/dt = 1/2  (d[SO_4^(2-)])/dt = 1/2 xx 2.2 xx10^-2 = 1.1 xx 10^-2  "M/s"`