N = given mass/ molar mass.
n = number of moles
given mass = 2.47 g
molar mass = 197 g/mol
n = 2.47 / 197
n = 0.01253 moles.
I'm sure you wanted to ask more than this. Just put some comments in. I can do the same.
You multiply 32 by 2, since there are two hydrogens in every water molecule.
The chemical reaction is expressed as:
3Ba(NO3)2 + 2Na3PO4 = Ba3(PO4)2 + 6NaNO3
To determine the percent yield, we need to determine the theoretical yield of the reaction from the given amounts of the reactants. We do as follows:
0.3 mol 3Ba(NO3)2 ( 2 mol Na3PO4 / 3 mol Ba(NO3)2) = 0.2 mol Na3PO4
Therefore, the limiting reactant would be Ba(NO3)2 since it is consumed completely in the reaction.
Theoretical yield = 0.3 mol 3Ba(NO3)2 ( 1 mol Ba3(PO4)2 / 3 mol Ba(NO3)2) = 0.1 mol Ba3(PO4)2
Percent yield = actual yield / theoretical yield = 0.095 mol Ba3(PO4)2 / 0.1 mol Ba3(PO4)2 x 100 = 95%
