To how much water should 100mL of 18M sulfuric acid be added to prepare a 1.5M solution?

Answer 1

Again here, we'll use the equation, C₁V₁ = C₂V₂ , Where the left side is the original solution (C₁V₁), and the right is the dilution or working solution (C₂V₂). Note that concentration and volume are inversely related. This time, we need to find out the new volume (V₂).

1. C₁ - original concentration
2. V₁ - original volume
3. C₂ - new concentration
4. V₂ - new volume

Plug it in, solving for new volume (V₂):

1. C₁V₁ = C₂V₂
2. (18 M)(100mL) = (1.5 M)(V₂)
3. (V₂) = (18 M • 100mL) / (1.5 M)
4.  V₂ = 1200 mL

Since you're adding water, make sure to subtract the 100mL volume you already have.

1. 1200mL - 100mL = 1100mL H2O added