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1. In preparation for a demonstration, your professor brings a 1.50L bottle of s

ID: 104442 • Letter: 1

Question

1. In preparation for a demonstration, your professor brings a 1.50L bottle of sulfur dioxide into the lecture hall before class to allow the gas to reach room temperature. If the pressure gauge reads 418 psi and the lecture hall is 22°C, how many moles of sulfur dioxide are in the bottle? In order to solve this problem, you will first need to calculate the pressure of the gas. Hint: The gauge reads zero when 14.7 psi of gas remains.

2. A 98L sample of dry air cools from 146°C to 44°C while the pressure is maintained at 2.00 atm. What is the final volume?

Explanation / Answer

1)

volume = 1.50 L

pressure = 418 + 14.7 = 432.7 psi

1 psi = 0.068 atm

pressure = 29.44 atm

temperature = 22 oC = 295 K

P V = n R T

29.44 x 1.50 = n x 0.0821 x 295

n = 1.823

moles of sulfur dioxide in bottle = 1.82 mol

2)

volume V1 = 98 L

T1 = 419 K

T2 = 317 K

V1 / T1 = V2 / T2

98 / 419 = V2 / 317

V2 = 74 L

final volume = 74 L