Question

Consider the following reaction was found to be the 0th order to A and 2nd order to B.

2A(cr) + 3B(aq) -->A2B3(cr)

Write a rate law equation for the reaction rate of A with B.

Answer 1

rate = k*[A]^o[B]²
OR you may omit the A terms since A raised to the zero power is 1. The "trick" to the problem, I suspect, is that many will write it as (A)^2*(B)^3.

Answer 2

Ok, thanks.

Couple follow ups:

Q1: If [A] is doubled how does the reaction rate change?

A: I put no change because 0th order cancels it out.

Q2: If [B] is doubled how does the reaction rate change?

A: I put it increases by a factor of 4 because of the squared term.

Q3: How would increase pressure effect the reaction rate?

A:???

Answer 3

Now that I look at Q3 I am thinking it is going to increase it, but not sure by what factor?

Answer 4

The answer to A is correct since it's zero order with respect to A. The answer to B is correct since 2^2 = 4.
Look at the equation. A is Cr which I assume means crystalline and that means a solid. B is aq which I assume means a liquid and A2B3 is cr which again I assume is a solid. Pressure will have an effect if reactants or products are gases; however, pressure has no effect on solids and essentially no effect on liquids. So increased pressure, I think, will have no effect on the rate of this reaction. .