Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

s Problem set Gas A.pdf (page 1 of 2) Concept check: Ideal Gas Equation, Avogadr

ID: 571371 • Letter: S

Question

s Problem set Gas A.pdf (page 1 of 2) Concept check: Ideal Gas Equation, Avogadro's hypothesis, gas density, molar volume 1. A balloon is filled with 3.00 L of He gas at 1 atm, 25'C a. How many moles of He gas in the balloon? b. If you need to expand the balloon to 6.00 L at same temperature and pressure, how many more moles of He you need to fill in? c If you released some of the gas, and the balloon size decreased to 1.00L at the same temperature and pressure, how many moles of He will be left in the balloon? 2. What is the density of CO, gas at 2.35 atm and 125 "C?

Explanation / Answer

1)

a)

we have:

P = 1.0 atm

V = 3.0 L

T = 25.0 oC

= (25.0+273) K

= 298 K

find number of moles using:

P * V = n*R*T

1 atm * 3 L = n * 0.0821 atm.L/mol.K * 298 K

n = 0.123 mol

Answer: 0.123 mol

b)

we have:

n1 = 0.123 mol

V1 = 3.00 L

V2 = 6.00 L

we have below equation to be used:

V1/n1 = V2/n2

3.0 L / 0.123 mol = 6.0 L / n2

n2 = 0.246 mol

mol to be added = n2 - n1

= 0.246 - 0.123

= 0.123 mol

Answer: 0.123 mol

c)

we have:

n1 = 0.123 mol

V1 = 3.00 L

V2 = 1.00 L

we have below equation to be used:

V1/n1 = V2/n2

3.0 L / 0.123 mol = 1.0 L / n2

n2 = 0.0410 mol

Answer: 0.0410 mol

Only 1 question at a time please