How many moles of h2so4 are in 2.50 l of 4.25 m aqueous solution?

The formula for molarity is:
M = n/V
or
M = mol/L

All you need to do is substitute the values you are given.
M = 4.25
L = 2.5
n = ?

4.25 = n/2.5
Multiply both sides by 2.5 to isolate n.

10.625 = n

There are 10.6 moles of H2So4 in the aqueous solution.