Can anyone help with Stoichiometry problems?

Cu + AgNO3 --> Ag + CuNO3 there is a 1:1 ratio here. So you convert 2 25 grams silver into moles (divide by molecular mass) and that is the number of moles of each thing Unless the reaction is Cu + 2AgNO3 --> 2Ag + Cu(NO3)2 then the number of moles of all the copper stuff is half the moles of the silver stuff a. 2 mol is less, so HCl limits b. 2.5 moles zn requires 5 moles HCl, so Znlimits - 5 < 6 c, 4 X 3/2 = 6, so the Fe compound limits - 6 < 6.5

Cu + AgNO3 --> Ag + CuNO3 there is a 1:1 ratio here. So you convert 2 25 grams silver into moles (divide by molecular mass) and that is the number of moles of each thing Unless the reaction is Cu + 2AgNO3 --> 2Ag + Cu(NO3)2 then the number of moles of all the copper stuff is half the moles of the silver stuff a. 2 mol is less, so HCl limits b. 2.5 moles zn requires 5 moles HCl, so Znlimits - 5 < 6 c, 4 X 3/2 = 6, so the Fe compound limits - 6 < 6.5

For the 1st reaction, you need to find the number of moles of each reactant. You do 2.25g x (1 mol/ 107.87 (molar mass of silver)) to get the moles of silver. Since Cu + 2AgNO3 --> Cu(NO3)2 + 2Ag shows that there's a 2/1 mol ratio of Cu and Ag, then the number of Cu moles produced equals twice the Ag moles produced. So whatever you got from the first part x2 is your answer. For the limiting reactants, look at the number of moles needed to carry out the reaction. For part a, you can see you need just 1 mol HCl for every mol of NaOH. So since you have 2 mol of that and 2.5 mol of NaOH, (aka a bit less), HCl is the limiting reactant. For part b, it's a little different since you need 2 mol of HCl for every 1 mol of Zn. So, since you have 6, you can divide that by 2 to get 3. 3 moles of HCl is more than 2.5 mol of Zn, so Zn is the limiting reactant. Just keep dividing what you have by the ratios presented in the reaction equation. I hope I made sense?