Question

What is the mass of 3 L of water vapor at

125°C and 383 torr?
O 1. 0.666583 g
O 2. 1.04154 g
O 3. 1.24984 g
O 4. 0.555486 g
5. 0.833229 g

Answer 1

5. 0.8334 g

Step-by-step explanation:

Given data:

Volume of water vapors = 3 L

Temperature = 125°C

Pressure = 383 torr

Mass of water vapors = ?

Solution:

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K

T = temperature in kelvin

Now we will convert the temperature.

125+273 = 398 K

383torr × 1 atm /760 torr = 0.503947 atm

PV = nRT

0.503947 atm × 3L = n × 0.0821 atm.L/ mol.K × 398 K

1.5111841 atm.L = n ×32.68 atm.L/ mol

n = 1.512 atm.L /32.6758 atm.L/ mol

n = 0.0463 mol

Mass of water vapors:

Mass = number of moles × molar mass

Mass = 0.0463 × 18 g/mol

Mass = 0.8334 g