# Question #2ed61

##### 1 Answer

#### Explanation:

The idea here is that you need to use the molar volume of a gas at STP to determine what the *molar mass* of nitrogen gas is.

Next, you meed to use the ideal gaas law equation to find how many moles of nitrogen gas you have in that volume and at those specific conditions for pressue and temperature.

So, at **STP**, or Standard Temperature and Pressure, *one mole* of any ideal gas occupies exactly

This means that if *molar mass* of nitogen gas is

The ideal gas law equation looks like this

#color(blue)(PV = nRT)" "# , where

*universal gas constant*, usually given as

You need to find the mass of sample of nitrogen gas that

- occupies a volume of
#"5.6 L"# - has a pressure of
#"38 mmHg"# - has a temperature of
#273^@"C"#

Plug in your values and solve the ideal gas law equation for **do not** forget to convert the pressure from *mmHg* to *atm* and the temperature from *degrees Celsius* to *Kelvin*!

#n = (38/760color(red)(cancel(color(black)("atm"))) * 5.6color(red)(cancel(color(black)("L"))))/(0.082(color(red)(cancel(color(black)("atm"))) * color(red)(cancel(color(black)("L"))))/("mol" * color(red)(cancel(color(black)("K")))) * (273.15 + 273)color(red)(cancel(color(black)("K"))))#

#n = "0.00625 moles"#

Now use nitrogen's molar mass to determine how many grams would contain this many moles

#0.00625color(red)(cancel(color(black)("moles"))) * "28 g"/(1color(red)(cancel(color(black)("mole")))) = color(green)("0.18 g")#