Question

1. Use the molar volume to calculate each of the following at STP:

A.Calculate the number of moles of CO2 in 1.40 L of CO2 gas. Express your answer to three significant figures and include the appropriate units.

B.Calculate the volume, in liters, occupied by 0.200 mol of He gas.Express your answer to three significant figures and include the appropriate units.

C.Calculate the volume, in liters, occupied by 4.00 g of O2 gas.Express your answer to three significant figures and include the appropriate units.

D.Calculate the number of grams of Ne contained in 8.80 L of Ne gas.Express your answer to three significant figures and include the appropriate units.

2. A 0.208 g sample of carbon dioxide, CO2, has a volume of 527 mL and a pressure of 483 mmHg .

What is the temperature of the gas in kelvins? Express your answer to three significant figures.

3.When sensors in a car detect a collision, they cause the reaction of sodium azide, NaN3, which generates nitrogen gas to fill the air bags within 0.03 s.
2NaN3(s)→2Na(s)+3N2(g)

How many liters of N2 are produced at STP if the air bag contains 139 g of NaN3? Express your answer with the appropriate units

Answer 1

1)

molar volume is 22.4 L/mol

A)

number of mol = volume / molar volume

= 1.40 L / 22.4 L/mol

= 0.0625 mol

Answer: 0.0625 mol

B)

Volume = number of mol * molar volume

= 0.200 mol * 22.4 L/mol

= 4.48 L

Answer: 4.48 L

C)

Molar mass of O2 = 32 g/mol

mass(O2)= 4.00 g

use:

number of mol of O2,

n = mass of O2/molar mass of O2

=(4 g)/(32 g/mol)

= 0.125 mol

Use:

volume = number of mol * molar volume

= 0.125 mol * 22.4 L/mol

= 2.80 L

Answer: 2.80 L

D)

number of mol = volume / molar volume

= 8.80 L / 22.4 L/mol

= 0.393 mol

Molar mass of Ne = 20.18 g/mol

use:

mass of Ne,

m = number of mol * molar mass

= 0.393 mol * 20.18 g/mol

= 7.931 g

Answer: 7.93 g

Only 4 parts at a time