Chemistry · Rate of a chemical reaction, factors affecting the rate of reactions: concentration, temperature, pressure and catalyst

For the reaction: . the expression }{d t} \) represents:

For the reaction: \( 2 H I \rightarrow H_{2}+I_{2} \). the expression \( \frac{-1}{2} \frac{d(H I)}{d t} \) represents:

  • A. the rate of formation of \( H I \)
  • B. the rate of disappearance of \( H I \)
  • C. the instantaneous rate of the reaction
  • D. the average rate of reaction

Step-by-step solution

For the reaction 2HI → H₂ + I₂, the rate of reaction is defined as -(1/2) d[HI]/dt, which represents the instantaneous rate of the reaction. Option A is incorrect because HI is a reactant, so its rate of formation is negative. Option B is incorrect because the rate of disappearance of HI is -d[HI]/dt, not divided by 2. Option D is incorrect because the expression uses a derivative, indicating an instantaneous rate rather than an average rate over a time interval.
Practise more in this unitView MCQsSign up for full question bank