Posted by **Casey** on Sunday, July 11, 2010 at 12:57pm.

If 10.0g of CaCl2 and 10.0g of NaCl are dissolved in 100.0mL of solution, what is the concentration of chloride ions? (the molar mass of CaCl2 is 111.0g/mol; the molar mass of NaCl is 58.44g/mol.

I found individual molar mass of:

Ca-40.08

Cl-35.45

Na-22.99

So I divided 10g CaCl2/111.0g CaCl2 + 10g NaCl/58.44g NaCl = .262205764. I than divided by .100L = 2.61205764.

I than divided 70.9g/111.0g and 35.45g/58.44g, added them together and came up with 1.245305065.

The final answer is 3.51M.

I cannot figure out where this answer came from. Help please.

- Chemistry -
**DrBob222**, Sunday, July 11, 2010 at 2:05pm
I expect if I look really hard I could find exactly where you went off track but it is easier to show you how to do the problem.

Plan: Determine molarity CaCl2 and molarity NaCl, then multiply M CaCl2 by 2 (to find M Cl) and add to molarity NaCl.

mols CaCl2 = 10/111 = 0.09

M = moles/L = 0.09/0.1 = 0.9 M CaCl2

M Cl in CaCl2 is 2 x 0.9 = 1.8

moles NaCl = 10/58.44 = 0.171

M = moles/L = 0.171/0.1 = 1.71 M NaCl.

then 1.8 + 1.71 = 3.51 M to three s.f.

## Answer This Question

## Related Questions

- Chemistry - If 10.0g of CaCl2 and 10.0g of NaCl are dissolved in 100.0mL of ...
- chemistry - 1. How many grams of calcium chloride (CaCl2) are there in 600.0 mL ...
- chemistry - If you know that the mass concentration of a NaCl solution is 58.5 g...
- chemistry - What mass (in grams) of CaCl2(s) must be dissolved in pure water at ...
- chemistry URGENT (1) - What mass (in grams) of CaCl2(s) must be dissolved in ...
- chem - How many grams of CaCl2 (molar mass = 111.0 g/mol) are needed to prepare ...
- Chemistry - If there are 0.625 g of NaCl left in a beaker that originally ...
- AP Chem - An aqueous solution contains 4.50 g of calcium chloride, CaCl2, per ...
- chemistry - If there are 0.561 g of NaCl left in a beaker that originally ...
- chemistry - I have two that I can not figure out: #1: calculate the MOLALITY of ...

More Related Questions