[flipyoudork]

I am really confused in how to solve the questions listed below:
1) How many grams of an insect repellent containing 14% N, N-dimethylmetatoluidine, C9H13N, can be prepared from 1.5 mol of C9H13N?

I tried using 1.5mols divided by the molar mass and time it by .14 but my friend insisted that thats wrong...

2) Finding Net Ionic Equations for 2NH3+H3PO4-->(NH4)2HPO4, 2ClO2+2NaOH--> NaClO2+NaClO3H2O
I have balanced the equations out but I'm not sure which can become ions and such...

Another net ionic question I didn't undertsand was : Calcium Carbonate reacts with sulfuric acid to form Calcium Hydrogen Sulfate and another product.

[flipyoudork]

For the first net ionic problem I got 2NH3+2H--->2NH4 but I am not sure if it is right.

[Yggdrasil]

You multiply moles by the molar mass to find the number of grams.  Remember that the units in a calculation need to make sense:

1.5 mol * 135 g/mol = 202.5 g
when you multiply the number of grams by the molar mass, the units here make sense

1.5 mol / (135 g/mol) = 0.0111 mol²/g
when you divide, the units make no sense at all

moral of the story: include units in your equations.  They make life easier.

[flipyoudork]

I did 1.5*135.23g but I don't know how is it right to multiply by .14 to find the grams of Nitrogen?

[Yggdrasil]

(compound/total) = 0.14
total = compound/0.14