Question

How do i calculate the concentration of H2O2 after 150 mL of distilled water is added to 30 mL of 1.0 M of H2O2?

Answer 1

You can use c1v1 = c2v2

c = concn
v = volume
I prefer just a simple ratio of
1.0M x (30/180) = ? and that assumes the solutions are additive.