Question

Question 10 of 23 Submit What is the mass of 15.00 L of propane vapor (C3H8) at STP? (1 2 3 +/- 0 x 100 Tap here or pull up for additional resources

Answer 1

Given:

P = 1.0 atm

V = 15.0 L

T = 273.0 K

find number of moles using:

P * V = n*R*T

1 atm * 15 L = n * 0.08206 atm.L/mol.K * 273 K

n = 0.6696 mol

Molar mass of C3H8,

MM = 3*MM(C) + 8*MM(H)

= 3*12.01 + 8*1.008

= 44.094 g/mol

use:

mass of C3H8,

m = number of mol * molar mass

= 0.6696 mol * 44.09 g/mol

= 29.52 g

Answer: 29.5 g