Ajinkya J. answered • 6d

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In this case, we're starting with 0.219g N_{2}O. Let's go ahead and convert that to moles by using the molar mass, which is 44.013 g/mol.

.219 g N_{2}O * (1 mol N_{2}O / 44.013 g N_{2}O) = 0.00497 mol N_{2}O

So we got to moles of dinitrogen monoxide - now we need to know how many moles of nitrogen! We see that there's a subscript of 2 after the N, meaning there are two moles of N for every mol of N_{2}O. You can think of it in terms of food -- for every 1 sandwich, there are two pieces of bread.

So let's multiply the number of moles of N_{2}O by 2, to get moles of N!

.00497 mol N_{2}O * ( 2 mol N / 1 mol N_{2}O) = .00994 mol N!