Question

If 10.0g of CaCl2 and 10.0g of NaCl are dissolved in 100.0mL of solution, what is the concentration of chloride ions?

I found the molar mass of CaCl2 is 111.0g/mol; the molar mass of NaCl is 58.44g/mol.

I divided 10g CaCl2/111.0g CaCl2
I divided 10g NaCl/588.44g NaCl and added the figures together and divided by .100L. The answer came out to 2.612057642. After comparing to my answer key, the answer is 3.51M. Can someone tell me what I'm doing wrong?

Answer 1

I thought I worked this for you a couple of nights ago.
moles Cacl2 in 10 g CaCl2 = 10/111 = 0.090 moles CaCl2
moles Cl in that is 0.090 x 2 = 0.180 moles Cl.
moles NaCl in 10 g NaCl = 10/58.44 = 0.171 moles

total moles Cl = 0.171 + 0.180 = 0.351
M = moles/L = 0.351 moles Cl/0.100 L = 3.51 M.

Answer 2

Obtain a clear glass and fill it with water. Or, observe water as it pours from a faucet. List at least five physical properties of the water (five words that describe the water).