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JEE Main levelSingle correct optionDifficulty 2 of 3pn155

The contact process is operated at about 720 K and not at much lower temperature, although the forward reaction is exothermic, because

  1. A decomposes completely at lower temperature
  2. Bthe catalyst is destroyed below 720 K
  3. Cthe rate of reaction would be too low at lower temperatures
  4. Dthe forward reaction becomes endothermic at lower temperature

Answer: C

Lower temperature favours a higher equilibrium conversion for an exothermic reaction, but the rate becomes very small. A compromise temperature with the V2O5 catalyst gives an acceptable rate and yield.
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