Question

How many molecules of nitrogen gas are found in 0.045 L of nitrogen gas at STP

Answer 1

1.2 × 10²¹ molecules

Step-by-step explanation:

Step 1: Given data

• Volume of nitrogen gas (V): 0.045 L

• Conditions: Standard temperature (273.15 K) and standard pressure (1 atm)

Step 2: Calculate the number of moles corresponding to 0.045 L of nitrogen gas at STP

At STP, 1 mole of nitrogen gas occupies 22.4 L.

0.045 L × 1 mol/22.4 L = 2.0 × 10⁻³ mol

Step 3: Calculate the number of molecules in 2.0 × 10⁻³ moles of nitrogen

We will use Avogadro's number: there are 6.02 × 10²³ molecules in 1 mole of molecules of nitrogen gas.

2.0 × 10⁻³ mol × 6.02 × 10²³ molecules/1 mol = 1.2 × 10²¹ molecules