Is this equation balanced? 2h2s+3o2→2so2+2h2o

Yes and you can check the balance by doing the following (check explanation):

Explanation:

(1) Count how much of each element you'll need and if they are grouped together as one

(2) When I was in Chemistry a while ago, I found it helpful to write down the number of atoms per element.

(3) See how much multiple you need to get from the before and after

(4) Check out some practice problems for more: Balancing Chemical Equations Practice Problems by Tyler DeWitt