A is a limiting reagent (LR) problem. You know that when you are given amounts for BOTH reactants. You use BOTH to determine which is the limiting reagent, then use the one that is the LR.
Right. You have 0.05 mol BaCl2 and you have 0.045 mols K2SO4.
a. Convert mols BaCl2 to mols BaSO4. Since that's 1:1 you could get 0.05 mols BaSO4 IF you had all of the K2SO4 you need to do that.
b. Convert mols K2SO4 to mols BaSO4. You can get 0.045 mols BaSO4 from that IF you had all of the BaCl2 needed to do that.
c. in LR problems, the correct value of BaSO4 you get is ALWAYS the smaller number because, in this case, the K2SO4 is the limiting reagent. So you know you get 0.045 mols BaSO4.
d. Convert to grams. mols BaSO4 x molar mass BaSO4 = grams BaSO4; i.e., 0.045 x 233.4 = 10.5 grams.
I didn't work through the others but probably they are the same type.
For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate...?
For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate. (Begin by writing a chemical equation for the reaction):
K2SO4(aq)+BaCl2(aq)=BaSO4(s)+2KCl(aq)
A) 500.0 mL of 0.100 M BaCl2 and 90.0 mL of 0.500 M K2SO4 Answer: 10.5g BaSO4
B) 100.0 mL of 0.100 M BaCl2 and 100.0 mL of 0.500 M K2SO4 Answer: 2.33g BaSO4
C) 100.0 mL of 0.100 M BaCl2 and 500.0 mL of 0.500 M K2SO4 Answer: 2.33g BaSO4
I need to know how to solve this problem, but I don't understand how to actually do it.
For A, I started with finding the mol of BaCl2, which is 0.0500 mol BaCl2, and for K2SO4, 0.045 mol K2SO4.
Then I use Stoichiometry calculations:
0.05 mol BaCl2*1 mol BaSO4/1 mol BaCl2* 208.2g BaSO4/1 mol BaSO4= 10.4g BaSO4.
Then I did the other information given, because I was given information about K2SO4 (mainly because I don't know what I am doing and if I should actually do it.):
0.045 mol K2SO4*1 mol BaSO4/1 mol K2SO4*208.2g BaSO4/1 mol BaSO4= 9.37g BaSO4
For B, 0.01 mol BaCl2 and 0.05 mol K2SO4.
0.01 mol BaCl2*1 mol BaSO4/1 mol BaCl2*208.2g BaSO4/1 mol BaSO4= 2.08g BaSO4
0.05 mol K2SO4*1 mol BaSO4/ 1 mol K2SO4*208.2g BaSO4/1 mol BaSO4= 10.4g BaSO4
I am doing something wrong, maybe I missed a step or something. Do I really need to use both of the information given? Because this is really confusing the hell out of me. Textbook: ISBN:978-0-07-340267-3
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