Chemistry - Partial pressure and mole composition of the gas mixture.

carbon dioxide = 60 kPa, oxygen = 90 kPa.

Total pressure is 100kPa.

Step 1 Calculate the mole of each gas.
Step 2 Solve for total pressure using the expression below.
total pressure X mole of H₂ / total mole = 60 kPa

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Assume you have 100 grams of the mixture of which 20% is CO₂, 55% O₂ and 25% N₂.
Convert the percentages into masses and work out the number of mole of each gas.
Then use the expression
Total pressure X mole of gas / total mole = partial pressure

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carbon dioxide = 58.82 kPa, oxygen = 224.84 kPa and nitrogen = 116.34

Partial pressure

Mole composition

The partial pressure of a gas is proportional to the number of mole of that gas in the gas mixture.

For example. 7 mole of gas "A" is mixed with 3 mole of gas "B" in a sealed vessel. The total pressure of the mixture is 100kPa.

The partial pressure of gas "A" is given by the expression
=> total pressure X (mole of "A")/ (Total number of mole)
=> 100 X 7/10 = 70 kPa.
The partial pressure of gas "B" is
=> 100 X 3/10 = 30 kPa

A gas mixture consists of 66 grams of carbon dioxide(CO₂) and 70 grams of nitrogen(N₂). The pressure of the mixture is 100kPa. What is the pressure that each gas exerts?
Atomic mass C=12,O=16,N=14
Step 1 Find the moles of each gas
Mole =mass/molar mass
Mole of carbon dioxide = 66/44 =1.5 mole
Mole of nitrogen = 70/28 =2.5 mole
Total mole of gas is 4.

The pressure exerted by carbon dioxide is given by the expression
=> Total pressure X mole of CO₂ / total mole = 100 X 1.5/4 = 37.5 kPa

The pressure exerted by nitrogen is given by the expression
=> Total pressure X mole of N₂ / total mole = 100 X 2.5/4 = 62.5 kPa

1) A mixture of gases contains 88 grams of carbon dioxide(CO₂) and 96 grams of oxygen(O₂) gas. If the pressure of the mixture is 150 kPa find the partial pressure of each gas.
Atomic mass C=12,O=16
Answer

2) A gas mixture in a metal cylinder consists of 64 grams of oxygen, 56 grams of nitrogen and 12 grams of hydrogen. If the partial pressure exerted by the hydrogen gas is 60 kPa calculate the total pressure of the mixture.
Atomic mass O=16,C=12,H=1,N=14
Clues
Answer

3) A gaseous mixture consists of 20% CO₂, 55% O₂ and 25% N₂. If the total pressure exerted by the mixture is 400 kPa calculate the partial pressures of each gas.
Atomic masses C=12,O=16,N=14
Clues

Answer

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