Describe the preparation of k2cr2o7 from chromite ore and explain the reaction of k2cr2o7 with acid FeSo4 - KI and H2S -

K2Cr2O7 is prepared from the chromate or ferrochrome ore whose molecular formula is nbsp;FeO.Cr2O3. The steps involved are as follows:(a) Preparation of sodi ...

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Standard XII

Chemistry

Solvation and Dissolution

describe the ...

Question

describe the preparation of k₂cr₂o₇ from chromite ore and explain the reaction of k₂cr₂o₇ with acid FeSo₄, KI and H₂S ?

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Solution

K₂Cr₂O₇ is prepared from the chromate or ferrochrome ore whose molecular formula is FeO.Cr₂O₃. The steps involved are as follows:
(a) Preparation of sodium chromate
4FeO.Cr₂O₃ + O₂ â†’ Fe₂O₃ + 4Cr₂O₃
4Na₂CO₃ + 2Cr₂O₃ + 3O₂ â†’ 4Na₂CrO₄ + 4CO₂
(b) Conversion of sodium chromate into sodium dichromate.
2Na₂CrO₄ + H₂SO₄ â†’ Na₂Cr₂O₇ + Na₂SO₄ + H₂O
(c) Conversion of sodium dichromate into potassium dichromate.
Na₂Cr2O₇ + 2KCl â†’ K₂Cr₂O₇ + 2NaCl
Chemical properties:
- Reaction with Acidic FeSO₄: Ferric sulphate is formed
K₂Cr₂O₇ + 7H₂SO₄ + 6FeSO₄ â†’ K₂SO₄ + Cr₂(SO₄)₃ + 3Fe₂(SO₄)₃ + 2H₂O

- Reaction with KI: Iodine is released
K₂Cr₂O₇ + 7H₂SO₄ + 6Kl â†’ 4K₂SO₄ + Cr₂(SO₄)₃ + 3l₂ + 7H₂O

- Reaction with H₂S: Sulphur is formed.
K₂Cr₂O₇ + 4H₂SO₄ + 3H₂S â†’ K₂SO₄ + Cr₂(SO₄)₃ + 7H₂O + 3S

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Similar questions

Q. Explain the preparation of K2Cr2O7 from chromite ore and write the chemical equations involved?

Q. Indicate the steps in the preparation of

K_{2} {C r}_{2} O_{7}

from chromite ore.

Indicate the steps in the preparation of:

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(ii) KMnO4 from pyrolusite ore.

Q. Indicate the steps in the preparation of:
(i)

K_{2} C r_{2} O_{7}

from chromite ore. (ii)

K M n O_{4}

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Q. Complete and balance the following chemical equations:
(i)

K M n O_{4} + K I + H_{2} S O_{4} \to

_________ + ____________ + __________ + ____________
(ii)

K_{2} C r_{2} O_{7} + H_{2} S O_{4} + H_{2} S \to

__________ + ________ + __________+ _________
(iii)

K M n O_{4} + H_{2} S O_{4} + F e S O 4 \to

__________ + ________ + __________+ _________

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describe the preparation of k2cr2o7 from chromite ore and explain the reaction of k2cr2o7 with acid FeSo4 , KI and H2S ?

describe the preparation of k₂cr₂o₇ from chromite ore and explain the reaction of k₂cr₂o₇ with acid FeSo₄, KI and H₂S ?