Question

1.5L of water is boiled to steam at a temperature of 100°C and creates 3.5atm of pressure on the container. How many moles of steam is present?

Answer 1

Answer: 1.7 moles

Explanation:

Given that:

Volume of water V = 1.5L

(since 1 liter = 1dm3

1.5L = 1.5dm3)

Temperature T = 100°C

Convert Celsius to Kelvin

(100°C + 273 = 373K)

Pressure P = 3.5 atm

Number of moles of steam N = ?

Note that Molar gas constant R is a constant with a value of 0.0082 ATM dm3 K-1 mol-1

Then, apply ideal gas equation

pV = nRT

3.5atm x 1.5dm3 = n x (0.0082 ATM dm3 K-1 mol-1 x 373K)

5.25 = n x 3.06

n = 5.25/3.06

n = 1.7 moles

Thus, 1.7 moles of steam is present