Question

A 2.50 L flask was used to collect a 1.65 g sample of propane gas, . After the sample was collected, the gas pressure was found to be 736 mmHg. What was the temperature of the propane in the flask

Answer 1

788.6K

Step-by-step explanation:

First, let us calculate the number of mole propane(C3H8). This can be achieved as shown below:

Molar Mass of C3H8 = (3x12) + (8x1) = 36 + 8 = 44g/mol

Mass of C3H8 obtained from the question = 1.65g

Number of mole = Mass /Molar Mass

Number of mole of C3H8 = 1.65/44 = 0.0375mol

Now we can obtain the temperature of propane gas as shown below:

V = 2.50L

P = 736mmHg

Recall that 760mmHg = 1atm

Therefore 736mmHg = 736/760 = 0.97atm

n = 0.0375mol

R = 0.082atm.L/Kmol

T =?

PV = nRT

T = PV/nR

T = 0.97x 2.5 / 0.0375x0.082

T = 788.6K

The temperature of the propane was 788.6K

Answer 2

The temperature of propane in the flask was 788.9 K or 515.75 °C

Step-by-step explanation:

Step 1: Data given

Volume of the flask = 2.50 L

Mass of propane = 1.65 grams

Molar mass of propane = 44.1 g/mol

Pressure = 736 mmHg = 0.968421 atm

Step 2: Calculate moles propane

Moles propane = mass propane / molar mass propane

Moles propane = 1.65 grams / 44.1 g/mol

Moles propane = 0.0374 moles

Step 3: Calculate temperature

p*V = n*R*T

T = (p*V)/(n*R)

⇒with T = the temperature in the flask

⇒with p = the pressure of propane gas = 0.968421 atm

⇒with V = the volume of the flask = 2.50 L

⇒with n = the number of moles propane gas = 0.0374 moles

⇒with R = the gas constant = 0.08206 L*atm/mol*K

T = (0.968421 * 2.50)/(0.0374*0.08206)

T = 788.9 K

The temperature of propane in the flask was 788.9 K or 515.75 °C