NEET Chemistry Redox Reactions Questions Solved


If 10 gm of V2O5 is dissolved in acid and is reduced to V2+ by zinc metal, how many mole of I2 could be reduced by the resulting solution if it is further oxidised to VO2+ ions ? [Assume no change in state of Zn2+ions] (V = 51, O =16, I = 127) :

(1) 0.11 mole of 12

(2) 0.22 mole of 12

(3) 0.055 mole of12

(4) 0.44 mole of 12

(1) 6e- + 10H+ + V2O5 → 2V2+ + 5 H2 O

Zn → Zn2+ + 2e- 3 × 3

V2O5 + 3 Zn + 10 H+ → 3Zn2+ + 2V2+ + 5H2O    … (1)

Now H2O + V2+ → VO2+ + 2H+ + 2e-

2e- + I2 → 2r-

V2+ + I2 + H2O → 2I- + VO2+ + 2H+

so we have 1 moles of V2O5 will reduce 2 moles of iodine

so 10102+80× 2 moles of will be reduced by given amount of V2O5 = 0.11moles of 12

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