Gas Mixtures and Partial Pressures

# Gas Mixtures and Partial Pressures - And so on for all...

This preview shows pages 1–2. Sign up to view the full content.

Gas Mixtures and Partial Pressures How do we deal with gases composed of a mixture of two or more different substances? John Dalton (1766-1844) - (gave us Dalton's atomic theory ) The total pressure of a mixture of gases equals the sum of the pressures that each would exert if it were present alone The partial pressure of a gas: The pressure exerted by a particular component of a mixture of gases Dalton's Law of Partial Pressures: P t is the total pressure of a sample which contains a mixture of gases P 1 , P 2 , P 3 , etc. are the partial pressures of the gases in the mixture P t = P 1 + P 2 + P 3 + . .. If each of the gases behaves independently of the others then we can apply the ideal gas law to each gas component in the sample: For the first component, n 1 = the number of moles of component #1 in the sample The pressure due to component #1 would be: For the second component, n 2 = the number of moles of component #2 in the sample The pressure due to component #2 would be:

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: And so on for all components. Therefore, the total pressure P t will be equal to: • All components will share the same temperature, T , and volume V , therefore, the total pressure P t will be: • Since the sum of the number of moles of each component gas equals the total number of moles of gas molecules in the sample: At constant temperature and volume, the total pressure of a gas sample is determined by the total number of moles of gas present, whether this represents a single substance, or a mixture Example A gaseous mixture made from 10 g of oxygen and 5 g of methane is placed in a 10 L vessel at 25°C. What is the partial pressure of each gas, and what is the total pressure in the vessel? (10 g O 2 )(1 mol/32 g) = 0.313 mol O 2 (10 g CH 4 )(1 mol/16 g) = 0.616 mol CH 4 V=10 L T=(273+25K)=298K P t = P O2 + P CH4 = 0.702 atm + 1.403 atm = 2.105 atm...
View Full Document

## This note was uploaded on 11/22/2011 for the course CHEMISTRY CHM1025 taught by Professor Laurachoudry during the Fall '10 term at Broward College.

### Page1 / 2

Gas Mixtures and Partial Pressures - And so on for all...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online