How many grams of urea, (NH2)2CO is produced if a total of 2.26x10^25 molecules of NH3 was used?

Question

Urea, (NH2)2CO is prepared by reactin ammonia with carbon dioxide.
2NH3 + CO2 = (NH2)2CO +H2O
If a total of 2.26x10^25 molecules of NH3 was used, how many grams of urea will be produced?

Oh, I see where I went wrong. I got 3.75 moles NH3 when dividing 2.26 x10^25 by 6.022 x 10^23 instead of 37.5. Thanks!

Answer 1

2NH3 + CO2 ---> (NH2)2CO +H2O

1. Get the number of moles by diving the number of molecules of NH3 by the avogadro's number.
moles NH3: 2.26x10^25 molecules / 6.022x10^23 molecules/mol
moles NH3: 37.53 moles

2. Since 1 mole of (NH2)2CO is produced for every 2 moles NH3, divide the resulting moles NH3 (#1) by 2 to get moles (NH2)2CO.
moles (NH2)2CO: 37.53 mol / 2 = 18.76 mol

3. Determine the weight of (NH2)2CO by multiplying its number of moles to its molecular weight.
weight (NH2)2CO: 18.76 mol * 60g/mol = 1125.6 grams