Question

In preparation for a demonstration, your professor brings a 1.50−L bottle of sulfur dioxide into the lecture hall before class to allow the gas to reach room temperature. If the pressure gauge reads 480 psi and the lecture hall is 25°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.

Answer 1

Answer:

n = 2.06 moles

Explanation:

The absolute pressure at depth of 27 inches can be calculated by:

Pressure = Pressure read + Zero Gauge pressure

Zero Gauge pressure = 14.7 psi

Pressure read = 480 psi

Total pressure = 480 psi + 14.7 psi = 494.7 psi

P (psi) = 1/14.696  P(atm)

So, Pressure = 33.66 atm

Temperature = 25°C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15  

So,  

T = (25 + 273.15) K = 298.15 K  

T = 298.15 K  

Volume = 1.50 L

Using ideal gas equation as:

PV=nRT

where,  

P is the pressure

V is the volume

n is the number of moles

T is the temperature  

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the equation as:

33.66 atm × 1.50 L = n × 0.0821 L.atm/K.mol × 298.15 K  

⇒n = 2.06 moles