Chemistry
posted by J.J on .
Hello! I'm doing these questions for my chemistry homework, and I can only figure out the first one, I don't know how to do the rest, I'm completely stuck! Please help!! Thank you!
1.) For the reaction, calculate how many grams of the product form when 18.4g of Ca completely reacts.
Assume that there is more than enough of the other reactant.
Ca(s)+Cl2(g)→CaCl2(s)
answer  50.9 g.
2.) For the reaction, calculate how many grams of the product form when 18.4g of Br2 completely reacts.
Assume that there is more than enough of the other reactant.
2K(s)+Br2(l)→2KBr(s)
answer  ?
3.) For the reaction, calculate how many grams of the product form when 18.4g of O2 completely reacts.
Assume that there is more than enough of the other reactant.
4Cr(s)+3O2(g)→2Cr2O3(s)
answer  ?
4.) For the reaction, calculate how many grams of the product form when 18.4g of Sr completely reacts.
Assume that there is more than enough of the other reactant.
2Sr(s)+O2(g)→2SrO(s)
answer  ?

2.) For the reaction, calculate how many grams of the product form when 18.4g of Br2 completely reacts.
Assume that there is more than enough of the other reactant.
2K(s)+Br2(l)→2KBr(s)
mols Br2 = grams/molar mass = estimated 0.1 but you should be more accurate than that.
Use the coefficients in the balanced equation to convert mols Br2 to mols KBr. That will be about 0.1 x (2 mol KBr/1 mol Br2) = estimated 0.2
Then convert mols KBr to g. g = mols x molar mass = about 0.2 x 119 = about 24.
ALL of these are worked the same way. The way I worked #2 will work all of them. I don't understand how you could do 1 and not do the others. 
wefwef