A student sets up two reactions. reaction 1 uses 0.230 mol/l of reactant, and reaction 2 uses 0.570 mol/l of reactant. how many times faster is reaction 2 compared to reaction 1?

Assuming that the rate of reaction is of first order, so that the rate is only dependent on the concentration A:

rate = - k A

So to know how much faster is reaction 2 compared to reaction 1, simply take the ratio of concentrations:

0.570 / 0.230 = 2.48

So reaction 2 is about 2.48 times faster.