# Question 47631

Apr 7, 2015

You have 0.00809 moles of nitrogen in that much nitrous oxide.

First, look at the molecular formula of nitrous oxide, ${N}_{\textcolor{red}{2}} O$.

Notice the $\textcolor{red}{2}$ subscript that follows nitrogen in the formula; what that subscript means is that 1 mole of nitrous oxide contains 2 moles of nitrogen.

So, to determine how many moles of nitrogen you have, you must first determine how many moles of nitrous oxide you have. To do that, use the compound's molar mass

0.178cancel("g") * ("1 moleN"_2"O")/(44.013cancel("g")) = "0.004044 moles " ${N}_{2} O$

This means that you get

0.004044cancel("moles"N_2O) * "2 moles N"/(1cancel("mole"N_2O)) = "0.008088 moles N"#

Rounded to three sig figs, the number of sig figs given for .178 g, the answer will be

${n}_{\text{nitrogen") = color(green)("0.00809 moles}}$