Question

What is the number density of the oxygen?

What is the pressure in the tank?

Assignment 1 Problem 18.24- Enhanced-with Video Solution What is the number density of the oxygen? Express your answer using two significant figures. Review A 20-cm-diameter cylinder that is 37 cm long contains 44 g of oxygen gas at 20 C You may want to review (Pages 500-502) For general problem-solving tips and strategies for this topic you may want to view a Video Tutor Solution of Air in warmed tire 7.1.10 In Submit Previous Answers Reauest Answer X Incorrect; Try Again Part D What is the reading of a pressure gauge attached to the tank? Express your answer to two significant figures and include the appropriate units.

Answer 1

Part C -

As we know, one mole of oxygen has a mass of 32g.

So, no. of moles in 44 g of oxygen = 44 / 32 = 1.375 moles

Now, one mole has 6.022x10^23 molecules

So, 1.375 moles has 1.375 x 6.022 x 10^23 = 8.28 x 10^23 molecules.

Diameter of the cylinder, d = 20 cm = 0.20 m

So, radius of the cylinder, r = d/2 = 0.10 m

So, volume of the cylinder, V = pi*r^2*h = 3.141*0.10^2*0.37 =  0.01162 m^3

Therefore, number density of the oxygen = n = N/V

= (8.28 x 10^23) / 0.01162 =  7.12 x 10^25 m^-3

In two significant digits the answer = 7.1 x 10^25 m^-3

Part D -

Use the expression -

P*V = nRT

=> P = nRT/V

= (1.375 * 8.314* (20+273)) / 0.01162 = 2.88 x 10^5 Pa

So, the reading of the pressure gauge = 2.9 x 10^5 Pa (Answer)