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500 g impure sample of CaCO 3 on heating gives 70 g of CaO . Percentage impurities in sample is

Options

  1. A25%
  2. B50%
  3. C75%
  4. D80%

Correct answer

C. 75%

Step-by-step solution

C a C O 3 → C a O + C O 2 Let the % purity is x Mol: 500 × X 100 × 100 mol 500 × X 100 × 100 × 56 = 70 X = 25 % Impurities = 100 - 25 = 75 %

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