# Calculate Gas Properties at Standard Temperature and Pressure (STP)

## What is the volume occupied by 34.06 grams of ammonia (NH3) gas at STP?

a. 44.8 liters

## How many grams of argon (Ar) gas are in 84.4 liters of argon gas at STP?

b. 149.8 grams

## Answer:

a. 44.8 liters

b. 149.8 grams

If you've ever wondered about the properties of gases at Standard Temperature and Pressure (STP), you're in the right place! Let's break down the calculations for the volume of ammonia gas and the mass of argon gas under these conditions.

## Volume of Ammonia Gas at STP:

To determine the volume occupied by 34.06 grams of ammonia (NH3) gas at STP, we first need to convert the grams to moles and then utilize the molar volume at STP.

1 mole of NH3 has a molar mass of 17.03 grams (14.01 g/mol for nitrogen + 3 * 1.01 g/mol for hydrogen).

Number of moles of NH3 = 34.06 g / 17.03 g/mol = 2 moles

Since 1 mole of gas occupies 22.4 liters at STP, 2 moles of NH3 will occupy:

Liters occupied = 2 moles * 22.4 L/mol = 44.8 liters

Therefore, 34.06 grams of ammonia gas at STP will occupy 44.8 liters.

## Mass of Argon Gas at STP:

For calculating the grams of argon (Ar) gas in 84.4 liters at STP, the process involves converting liters to moles and then using the molar mass of argon.

1 mole of any gas occupies 22.4 liters at STP.

Number of moles of Ar = 84.4 L / 22.4 L/mol = 3.75 moles

The molar mass of argon (Ar) is 39.95 g/mol.

Grams of argon gas = 3.75 moles * 39.95 g/mol = 149.8 grams

Therefore, 84.4 liters of argon gas at STP will contain 149.8 grams of argon.