Chemistry · Factors affecting equilibrium: concentration, pressure, temperature, the effect of catalyst, Le Chatelier's principle

If the pressure of mixture in a closed apparatus is 100 atm and of the mixture r

If the pressure of \( N_{2} / H_{2} \) mixture in a closed apparatus is 100 atm and \( 20 \% \) of the mixture reacts then the pressure at the same temperature would be:

  • A. 100
  • B. 90
  • C. 85
  • D. 80

Step-by-step solution

Assuming the N2/H2 mixture is in the stoichiometric ratio 1:3 for ammonia synthesis. Initial total moles correspond to 100 atm. For every 4 moles of reactants consumed, 2 moles of product are formed, reducing total moles by 2. If 20% of the mixture reacts (i.e., 20% of initial moles are consumed), then the total moles decrease by half of that (since 2 out of 4 moles are lost), i.e., 10% of initial moles. Thus final pressure = 100 atm × (1 - 0.1) = 90 atm.
Practise more in this unitView MCQsSign up for full question bank