chemistry
posted by Tri .
A firstorder reaction initially proceeds at a rate of 0.5 mol/ls. What will be the rate when half the starting material remains? When onefourth of the starting material remains?

Isn't the rate for a first order reaction rate = k[A]?.
rate = 0.5
Make A anything and solve for k.
Then use rate = k[A].
you know k and [A] now is 1/2. Then 1/4. solve for rate for each. Check my thinking. 
I think that is good cause the rate is proportional to [A] as it is first order?