Posted by Bob on Monday, February 23, 2009 at 9:39am.
What is the theoretical yield of calcium carbonate if 2.97 grams of calcium chloride dihydrate reacts with excess sodium carbonate according to the balanced chemical reaction shown below?
CaCl2•2H20(aq)+Na2CO3(aq)>CaCO3(aq)+2NaCL(aq)+2H20(I)
Please use molar mass values calculated and rounded to the hundredths place, and round your answer to the hundredths place.
to find the molar mass, i did:
Ca = 40.08
Cl2 = (35.45) x 2 = 70.9
2H2O = (18.02) x 2 = 36.04
40.08 + 70.90 + 36.04 = 147.02 g/mol
To find the theoretical yield, i did:
2.97g CaCl•2H2O x (1 mol CaCl•2H2O/147.02g CaCl•2H2O) x (1 mol CaCO3/1 mol CaCl•2H2O) x (100.09/1 mol CaCO3) = 2.04 g
Did I do the theoretical yield equation correctly?

Chemistry  DrBob222, Monday, February 23, 2009 at 10:59am
Yes, your procedure is correct. I obtained 147.014 for CaCl2.2H2O and 100.087 for CaCO3 but I'm using a calculator on the internet and that may not agree with the numbers on your periodic table. They should agree if both contain the most up to date information. Using my numbr I obtained 2.0219 g for the theoretical yield, which rounds to 2.02. Here is the site I use for molar mass calculations if you wish to compare their numbers versus your numbers. http://environmentalchemistry.com/yogi/reference/molar.html