<u>Answer:</u> The concentration of chloride ions in the solution obtained is 0.674 M
<u>Explanation:</u>
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of KCl solution = 0.675 M
Volume of solution = 297 mL
Putting values in equation 1, we get:
![0.675=\frac{\text{Moles of KCl}\times 1000}{297}\\\\\text{Moles of KCl}=\frac{(0.675mol/L\times 297)}{1000}=0.200mol](https://tex.z-dn.net/?f=0.675%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20KCl%7D%5Ctimes%201000%7D%7B297%7D%5C%5C%5C%5C%5Ctext%7BMoles%20of%20KCl%7D%3D%5Cfrac%7B%280.675mol%2FL%5Ctimes%20297%29%7D%7B1000%7D%3D0.200mol)
1 mole of KCl produces 1 mole of chloride ions and 1 mole of potassium ion
Moles of chloride ions in KCl = 0.200 moles
- <u>For magnesium chloride:</u>
Molarity of magnesium chloride solution = 0.338 M
Volume of solution = 664 mL
Putting values in equation 1, we get:
![0.338=\frac{\text{Moles of }MgCl_2\times 1000}{664}\\\\\text{Moles of }MgCl_2=\frac{(0.338mol/L\times 664)}{1000}=0.224mol](https://tex.z-dn.net/?f=0.338%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20%7DMgCl_2%5Ctimes%201000%7D%7B664%7D%5C%5C%5C%5C%5Ctext%7BMoles%20of%20%7DMgCl_2%3D%5Cfrac%7B%280.338mol%2FL%5Ctimes%20664%29%7D%7B1000%7D%3D0.224mol)
1 mole of magnesium chloride produces 2 moles of chloride ions and 1 mole of magnesium ion
Moles of chloride ions in magnesium chloride = ![(2\times 0.224)=0.448mol](https://tex.z-dn.net/?f=%282%5Ctimes%200.224%29%3D0.448mol)
Calculating the chloride ion concentration, we use equation 1:
Total moles of chloride ions in the solution = (0.200 + 0.448) moles = 0.648 moles
Total volume of the solution = (297 + 664) mL = 961 mL
Putting values in equation 1, we get:
![\text{Concentration of chloride ions}=\frac{0.648mol\times 1000}{961}\\\\\text{Concentration of chloride ions}=0.674M](https://tex.z-dn.net/?f=%5Ctext%7BConcentration%20of%20chloride%20ions%7D%3D%5Cfrac%7B0.648mol%5Ctimes%201000%7D%7B961%7D%5C%5C%5C%5C%5Ctext%7BConcentration%20of%20chloride%20ions%7D%3D0.674M)
Hence, the concentration of chloride ions in the solution obtained is 0.674 M