Hi, I need to determine how many significant figures for k in this expression:

. I already got the question wrong by using 4 significant figures. I've concluded it must be temperature because I had originally used 298.15K (5 SF). I believe this is the error because I don't know if 25C (2SF) equals 298.15K (5SF).

The given parameters are:

A = 1

-E

_{a} = -5kcal / mol (-20920 J)

R = 8.314 J / K * mol

T = 25C (? K)

Before we can solve, we need to convert C to K. Using additive SF rules, the temperature in K should be 29

8.15K = 298. This means the final answer should have 3 SF because it was carried in from a previous operation. However, what if I punch in the entire operation (including the C--->K conversion factor) into my calculator? At first glance, it is not obvious why it wouldn't be 2SF as the temperature was originally taken at 25C and not 25.0C.

If the explanation of my problem is unclear, I can create a better visual. Thanks for the help.