Which of the following will react faster (i.e., produce more product more product in a given time) and will react at the highest rate ?
(i) 1 mol of A and 1 mol of B in a 1 L flask
(ii) 2 mol of A and 2 mol of B in a 2 L flask
(iii) `0.2` mol of A and `0.2` mol of B in a `0.1` L flask

Options

A. Fastest and highest rate (iii)
B. Fastest (iii) and highest rate (ii)
C. Fastest (ii) and highest rate (iii)
D. Fastest and highest rate (ii)

Answer

C

Explanation

Reaction is fastest (i.e., more products are formed per unit time) when the amount of reactants is more. The rate is more molar concentrations of reactants is more. Here, molar concentrations of A and B in (i) and (ii) are same but molar concentrations of A and B in (iii) are maximum i.e., `[A]=2M and [B]=2M`. As such rate is maximum in (iii). Products formed per unit time will be maximum in (ii) as it contains more of reactions (2 mole each of A and B)