If 1.8 l of water is added to 2.5l of a 7.0 molarity koh solution, what is the molarity of the new solution

4.1 mol·L⁻¹

Explanation:

You are diluting the solution with water, so you can use the dilution formula

c₁V₁ = c₂V₂     Divide each side by V₂

 c₂ = c₁ × V₁/V₂

Data:

c₁ = 7.0 mol·L⁻¹; V₁ = 2.5 L

Water added = 1.5 L

Calculations:

(a) New volume

V₂ = 2.5 L + 1.8 L

     = 4.3 L

(b) New concentration

c₂ = 7.0 × 2.5/4.3

    = 7.0 × 0.581

    = 4.1 mol·L⁻¹

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.