A mixture of 14.0 grams of hydrogen, 84.0 grams of nitrogen, and 2.0 moles of oxygen are placed in a flask. When the partial pressure of the oxygen is 78.00 mm of mercury, what is the total pressure in the flask?

The study of chemicals is called chemistry.

The correct answer is 468mmhg.

Dalton's law defined as partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases  

The formula is stated as follows:-

The partial pressure is the pressure of each gas in a mixture. For partial gas is as follows :

The defined as a mole fraction of gas 1

The mole of each gas is as follows:-

Total moles =

The partial pressure   is as follows:-

.

Hence, the correct answer is 468mmhg.

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Total pressure in the flask : 468 mmHg

Dalton's law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases  

Can be formulated:  

P tot = P1 + P2 + P3 ....  

The partial pressure is the pressure of each gas in a mixture  

For partial gas :

Pgas₁=x₁.P tot

x₁ = mole fraction of gas 1

mol of each gas :

H₂ = 14 g : 2 g/mol= 7 moles

N₂ = 84 g : 28 g/mol = 3 moles

O₂ = 2 moles

Total moles = 7+3+2= 12 moles

Partial pressure of O₂ :