Question

Consider the reaction: 2A(g)+B(g)→3C(g). When A is decreasing at a rate of 0.200 M⋅s−1 , how fast is B decreasing?

Answer 1

The molar ratios are based upon the coefficients in front for each 'chemical'. So, the molar ratio for A to B is 2 to 1. So, if it takes two molecules of A to react with one molecule of B to form C, then if A is decreasing at a rate of 0.200 M/s then B is decreasing by half that rate.