# Ammonia and oxygen produce nitrogen dioxide and water. What volume of nitrogen dioxide gas will be produced if 30.5 grams of ammonia is reacted with excess oxygen?

##### 1 Answer

40.7 L of

#### Explanation:

There are four steps involved in this stoichiometry problem:

**Step 1. Write the balanced chemical equation.**

**2. Convert grams of #"NH"_3# to moles of #"NH"_3#**

The molar mass of

∴

**Step 3.** Convert moles of

The molar ratio of

∴

**4. Use the Ideal Gas Law to calculate the volume of #"NO"_2#.**

The Ideal Gas Law is

#color(blue)(|bar(ul(color(white)(a/a) PV = nRTcolor(white)(a/a)|)))# , where

#P# = the pressure of the gas,#V# = the volume of the gas,#n# = the number of moles of the gas,#R# = the universal gas constant#T# = the temperature of the gas

You don't give the pressure or temperature of the gas, so I will assume STP (100 kPa and 0 °C).

We can rearrange the Ideal Gas Law to get

#color(blue)(|bar(ul(color(white)(a/a)V= (nRT)/Pcolor(white)(a/a)|)))" "#

The volume of

Here's a useful video on mass-volume calculations.