20,0g MgCl2 and 20,0g NaCl are mixed together and dissolved in water to make up 2,00dm cube of solution. Calculate the concentration of the chloride ions in the solution

1 answer

To calculate the concentration of chloride ions in the solution, we need to determine the moles of chloride ions present in the solution first.

First, let's calculate the moles of MgCl2:
Molar mass of MgCl2 = 24.305 g/mol + 2 * 35.453 g/mol = 95.211 g/mol

Moles of MgCl2 = 20.0 g / 95.211 g/mol = 0.20990 mol

Next, let's calculate the moles of NaCl:
Molar mass of NaCl = 22.990 g/mol + 35.453 g/mol = 58.443 g/mol

Moles of NaCl = 20.0 g / 58.443 g/mol = 0.342019 mol

Now, let's calculate the total moles of chloride ions in the solution:
Total moles of chloride ions = 2 * (0.20990 mol + 0.342019 mol) = 1.103818 mol

Finally, let's calculate the concentration of chloride ions in the solution:

Concentration (mol/dm^3) = Total moles of chloride ions / Volume of solution
Concentration (mol/dm^3) = 1.103818 mol / 2.00 dm^3

Concentration (mol/dm^3) ≈ 0.5519 mol/dm^3

Therefore, the concentration of the chloride ions in the solution is approximately 0.5519 mol/dm^3.