Question

At stp how many molecules of nitrogen gas are in 2.24 l

Answer 1

STP stands for Standard Temperature and Pressure. It defines approximately 0° C or 32 Fahrenheit for temperature and 1 atm for pressure.

Volume can be used ONLY for gases to determine their mole number at STP.

One mole gas occupies 22.4 liters (L). The type of gas doesn't matter. It may be 1 mole of oxygen gas (O₂), hydrogen gas (H₂), or nitrogen gas (N₂). Though they have different molar mass, their volumes of one mole equals 22.4 L.

Here is the formula of volume-mole relationship for GASES at STP.

mole= Volume given/ 22.4 L ; n= Vgiven/22.4 L

Apply that formula at the question. n=2.24/ 22.4 L= 0.1 mole N₂ gas 

To find out number of molecules, convert mole into number. 

Actually, 1 mole defines 6*10²³ particles but that number (Avogadro's number) is mostly used for atoms and molecules. 

1 mole apples mean  1*6*10²³ apples.
2 mole pens mean   2*6*10² pens.
1 mole iron (Fe) have 1*6*10²³ iron atoms.

By formula;
mole= number of particles / Avogadro's number ; n= N/ NA; n=N/6*10²³

So, N= n*6*10²³ ; N= 0.1*6*10²³ = 6* 10²² nitrogen molecules.

The answer is 6*10²² N₂ molecules.

Answer 2

Answer:

6.02 * 10∧22 number of molecules of nitrogen gas are in 2.24 l.

Explanation:

At standard temperature and pressure which is 0°C (32F) and 1 atm pressure, one mole is equal to 6.02 * 10∧23 number of molecules, atoms or ions.

This is known as Avogadro law.

All phases of matter whether it is liquid, gas or solid, the number of molecules in one mole will be same at STP.

2.24 l is equal to 0.1 mole of nitrogen gas.

Hence 1 mole = 6.02 * 10∧23 number of molecules.

           0.1 mole =  6.02 * 10∧23 × 0.1

                          =   6.02 * 10∧22 number of molecules.