## Test 1, Q1

princessturner1G
Posts: 31
Joined: Fri Apr 06, 2018 11:05 am

### Test 1, Q1

a)A solution of anhydrous iron chloride, FeCl3, is prepared by dissolving 10g of salt to 1L water. What is the concentration of chloride ions of the above solution?
b) The above solution is diluted with 1L of 0.100 M potassium chloride, KCL, solution. What is the concentration of chloride ions after the dilution?

I am having trouble solving part b. I am not sure what equation or what steps I should take to solve this.

Ellie Tsang 1I
Posts: 30
Joined: Fri Apr 06, 2018 11:05 am
Been upvoted: 1 time

### Re: Test 1, Q1

Use the equation M=mol/L to determine how many moles of KCl there are, which is 0.100 mol KCl. In 1 mole of KCl, there is 1 mole of Cl-, so there are 0.100 mol Cl-. Because the question asks for the concentration of Cl- after the dilution, take your answer from part a (0.185 mol Cl-) and add it to 0.100 mol Cl-. Because 1.00 L is added to the solution in part a, which is also 1 liter, the total volume of the solution is now 2.00 L. Use M-mol/L again to get 0.142 mol/L Cl-.

Karyn Nguyen 1K
Posts: 72
Joined: Fri Apr 06, 2018 11:04 am

### Re: Test 1, Q1

I'm a little confused on how we're supposed to know KCl --> K+ + Cl- . Also for CaCl2 --> Ca2+ + 2Cl-