Answer to Question #191300 in Chemistry for Robert

Question

What will be the quantitative concentration of the newly formed solution if we add 800 cm3 of water to 400 cm3 of hydrochloric acid solution, mass concentration of 12.25 g / dm3?

Answer 1

Solution:

hydrochloric acid - HCl

Convert units:

(800 cm³) × (0.001 dm³ / 1 cm³) = 0.8 dm³ H₂O

(400 cm³) × (0.001 dm³ / 1 cm³) = 0.4 dm³ HCl

(0.4 dm³ HCl) × (12.25 g HCl / 1 dm³ HCl) = 4.9 g HCl

New solution volume = 0.8 dm³ + 0.4 dm³ = 1.2 dm³

Hence,

(4.9 g HCl / 1.2 dm³) = 4.08 g/dm³ - the new mass concentration of HCl solution

OR:

(4.08 g/dm³) × (1 mol / 36.458 g) = 0.112 mol/dm³ = 0.112 M - the new molarity of HCl solution

Answer: 4.08 g/dm³ or 0.112 M is the quantitative concentration of the newly formed solution.