Answer:
0.126 mol/L
Explanation:
The chloride ions come to the salts NaCl and KCl, which dissociates completely in water. So let's calculated how much moles of Cl⁻ are formed for each salt, knowing that the molar masses are Cl = 35.5 g/mol, Na = 23 g/mol, and K = 39 g/mol.
MNaCl = 23+ 35.5 = 58.5 g/mol
MKCl = 39 + 35.5 = 74.5 g/mol
The number of moles is the mass divided by the molar mass, and 1 mol of the salts produces 1 mol of Cl⁻ :
nNaCl = 0.50/58.5 = 8.55x10⁻³ mol
nKCl = 0.30/74.5 = 4.03x10⁻³ mol
nCl⁻ = 8.55x10⁻³ + 4.03x10⁻³ = 0.01258 mol
The molar concentration is the number of moles divided by the solution volume (100 mL = 0.1 L):
0.01258/0.1 = 0.126 mol/L
