Question

The reaction a+3b→products has an initial rate of 0.0345 m/s, and the rate law is rate=k[a]2[b]. What will the initial rate be if [a] is quadrupled and [b] is halved?

a) 0.069 m/s
b) 0.103 m/s
c) 0.017 m/s
d) 0.207 m/s

Answer 1

To calculate the new initial rate when [a] is quadrupled and [b] is halved, substitute the new concentrations into the rate law equation and solve for k.

Step-by-step explanation:

The initial rate of a reaction can be calculated using the rate law equation and the given concentrations of reactants. In this case, the rate law is given as rate = k[a]^2[b]. To find the initial rate when [a] is quadrupled and [b] is halved, we can substitute the new concentrations into the rate law equation. Quadrupling [a] means multiplying it by 4, and halving [b] means dividing it by 2. So the new rate would be rate = k(4[a])^2(0.5[b]), which simplifies to rate = 16k[a]^2[b]. Since we know the initial rate is 0.0345 m/s, we can set up the equation 0.0345 m/s = 16k[a]^2[b] and solve for k, which will give us the new rate.