Question

The molar concentration of chloride ions when 300 ml of 3.0 M NaCl is added to 200 ml of 4.0 M BaCl2 is

Answer 1

1 mole NaCl has 1 mole of chloride ions
1 mole of BaCl₂ has 2 moles of chloride ions
So, number of moles of chloride ions in 3 M, 300ml NaCl = 900 mmol= 0.9 moles
Number of chloride ions in 4 M,200ml BaCl₂ = 800 x 2 mmol = 1600 mmol = 1.6 moles
Total volume of mixture = 300 + 200 = 500 ml = 0.5 L
Concentration of chloride ions in the mixture = number of moles/ volume in litres
= (0.9+1.6)/0.5
= 5 M