A sample of a gas at STP has its temperature raised to 510C and its pressure raised to 5 atm. If the initial volume of this gas is 100.0 ml, what will the final volume be?

(P1V1/T1) = (P2V2/T2)

Remember T must be in kelvin.

is the answer .98?

0.98 WHAT? No it isn't. If you will post your work I'll find the error.

p1v1/t1=p2v2/t2

(5)(100.0)/510=...

You have no T1 in your equation. You have not converted 510 C to kelvin for T2.

You have the equal sign in the wrong place. Substituee into the equation as is. Don't rearrange it until all of the numbers are in.
(P1V1/T1) = (P2V2/T2)
Write the down so you can follow what you're doing.
P1 = 1 atm
V1 = 100 mL
T1 = 273
etc

what do i plug in for v2 and p2 then?

Are we reading the same problem?

P1 = 1 atm (STP is standard T and P which is 273 for T and 1 atm for P)
V1 = 100 mL in the problem.
T1 = 273STP again.
P2 = 5 atm from the problem.
V2 = this is what you are to calculate.
T2 = 510 converted to kelvin.