chapter 10 Gasses

Question 1

combined gas law

Answer 1

PV/t = PV/t

Question 2

moles and volume proportion

Answer 2

V/n=V/n

Question 3

What is the volume occupied by 14.6 g of argon gas at a pressure of 1.50 atm and a temperature of 444 K ?

Answer 3

this is an ideal gas law questtion

Question 4

A weather balloon is inflated to a volume of 29.8 L at a pressure of 733 mmHg and a temperature of 26.4 ∘C. The balloon rises in the atmosphere to an altitude where the pressure is 385 mmHg and the temperature is -13.9 ∘C.

Assuming the balloon can freely expand, calculate the volume of the balloon at this altitude.

(steps)

Answer 4

1. find the number of moles with pvnrt

2. use that to find the volume at the new temp

Question 5

Which of the following gas samples, all at the same temperature, will have the greatest pressure?

a. 5 medium particles moving around
b. 10 small particles moving around
c. 8 large particles

Answer 5

Box b has the largest number of molecules floating around in it. Consequently it also has the largest velocity for each molecule. Force is mass times acceleration, thus the pressure is the total force due to the collisions of the particles in the wall. Thus b has the largest pressure.

Question 6

volume of gas at stp

Answer 6

22.4

Question 7

Use the molar volume of a gas at STP to calculate the density (in g/L) of carbon monoxide gas at STP.

Answer 7

The standard molar volume of a gas is 22.414 L/mol , and the molar mass of CO is 28.01 g/mol. The density is found by dividing the mass of a gas by its volume: d=m/V. Therefore, you can divide the molar mass of a gas (in grams per mole) by its molar volume (in liters per mole) to determine its density (in grams per liter).

Question 8

An experiment shows that a 110 mL gas sample has a mass of 0.173 g at a pressure of 751 mmHg and a temperature of 31 ∘C.

What is the molar mass of the gas?

Answer 8

The molar mass can be determined from the mass of the sample and the number of moles of the sample. The number of moles is determined by using the ideal gas law.

Question 9

Total pressure

Answer 9

is equal to the sum of the partial pressures

Question 10

A gas mixture contains each of the following gases at the indicated partial pressures: N2, 200 torr ; O2, 100 torr ; and He, 100 torr .

Answer 10

P =
400
torr

Question 11

given the partial pressures,find the total mass of each of the elements

Answer 11

1. use partial pressure and the ideal gas law to find the number of moles of each gas
2. use the molar mass to calculate the mass of each individual element in grams

Question 12

mole fraction

Answer 12

the amount of element X / the total amount of the elements

Question 13

What volume of air contains 11.4 g of oxygen gas at 273 K and 1.00 atm?

Answer 13

find the oxygen in terms of moles
find the volume with that many moles
use the mole fraction to adjust a bit

Question 14

given the EQ and the amount of the reactants

want the final volume of the gas produced

Answer 14

find the amount of product using limiting reaction chemistry

use that to calculate the final volume of the product with the ideal gas law