Question

Problem #2: What volume of ammonia at STP is produced if 30.0 g of nitrogen is reacted with an excess of hydrogen? N2 + 3H2 --> 2NH3

Answer 1

The first step to solve this question is to convert the given mass of nitrogen to moles:

`30gN_2\cdot(1molN_2)/(28g)=1.07molN_2`

Use the stoichiometric ratio to find how many moles of NH3 are produced:

`1.07molN_2\cdot(2molNH_3)/(1molN_2)=2.14molNH_3`

Use the ideal gases law to find the volume of ammonia produced:

`Pv=nRT`

Solve the equation for v and replace for the known values (since the gas is at standard temperature and pressure, T is 273K and P is 1atm). Remember that R is the ideal gas constant and has a value of 0.082atmL/molK:

`\begin{gathered} v=(nRT)/(P) \\ v=\frac{2.14\text{mol}\cdot\frac{0.082\text{atmL}}{\text{molK}}\cdot273K}{1\text{atm}} \\ v=47.9L \end{gathered}`

47.9L of ammonia are produced.