The reduction of peroxydisulphate ion by I- ion is expressed by S2O-28+3I-→2SO2-4+I-3 If rate of disappearance of I- is 9/2 × 10-3 mol L-1 S-1, what is the rate of formation of SO2-4 during same time?

Question

The reduction of peroxydisulphate ion by I- ion is expressed by S2O-28+3I-→2SO2-4+I-3 If rate of disappearance of I- is 9/2 × 10-3 mol L-1 S-1, what is the rate of formation of SO2-4 during same time? (A) 10-3 mol/L-1 s-1 (B) 2 × 10-3 mol/L-1 s-1 (C) 3 × 10-3 mol/L-1 s-1 (D) 4 × 10-3 mol/L-1 s-1

Tardigrade Admin · Accepted Answer

(1/2)(d[SO2-4]/dt)=(1/3)((d[I-]/dt)) (1/2)(d[SO2-4]/dt)=(1/3)×(9/2)×10-3 ∴ (d[SO2-4]/dt)=3×10-3mol L-1s-1

Q. The reduction of peroxydisulphate ion by $I^{-}$ ion is expressed by $S_{2} O_{8}^{- 2} + 3 I^{-} \to 2 S O_{4}^{2 -} + I_{3}^{-}$ If rate of disappearance of $I^{-}$ is $9/2 \times 1 0^{- 3} m o l L^{- 1} S^{- 1,}$ what is the rate of formation of $S O_{4}^{2 -}$ during same time?

$1 0^{- 3} m o l / L^{- 1} s^{- 1}$

$2 \times 1 0^{- 3} m o l / L^{- 1} s^{- 1}$

$3 \times 1 0^{- 3} m o l / L^{- 1} s^{- 1}$

$4 \times 1 0^{- 3} m o l / L^{- 1} s^{- 1}$

$\frac{1}{2} \frac{d [ S O _{4}^{2 -} ]}{d t} = \frac{1}{3} (\frac{d [ I ^{-} ]}{d t})$
$\frac{1}{2} \frac{d [ S O _{4}^{2 -} ]}{d t} = \frac{1}{3} \times \frac{9}{2} \times 1 0^{- 3}$
$∴ \frac{d [ S O _{4}^{2 -} ]}{d t} = 3 \times 1 0^{- 3} m o l L^{- 1} s^{- 1}$

Q. The reduction of peroxydisulphate ion by I− ion is expressed by S2​O8−2​+3I−→2SO42−​+I3−​ If rate of disappearance of I− is 9/2×10−3molL−1S−1, what is the rate of formation of SO42−​ during same time?

10−3mol/L−1s−1

2×10−3mol/L−1s−1

3×10−3mol/L−1s−1

4×10−3mol/L−1s−1