Relations between percent, molar and normal concentration
Answers are for parents and teachers.
1
A 20 % NaOH solution has a density of 1.2 g/mL. What is its molar concentration (M = 40)?
6
2
A 3 M NaOH solution has a density of 1.2 g/mL. What is its percent concentration (M = 40)?
10
3
A 2 M NaOH solution is 7.4 %. What is its density (M = 40)?
ρ = 2·40/(7.4·10) ≈ 1.08 g/mL
4
Find the molar concentration of 36.5 % HCl (ρ = 1.2 g/mL) (M = 36.5).
12
5
Why can 1 M H₃PO₄ be taken as 3 N for complete neutralisation?
H₃PO₄ can give three H⁺, so E = M/3 and C_N = 3·C_M.