Gases and Pressure Section 11.1

Vocabulary _____________: the force per unit area on a surface __________________: the force per unit area exerted against a surface by the weight of the air above that surface.

Measuring Pressure Figure 3- page 363 _______________: device used to measure atmospheric pressure First introduced by Evangelista __________ during the early 1600s. Discovered that ____________________ supports a column of mercury about _____ _____above the surface of Hg in a dish

Units of Pressure There are several units for pressure ____________, also called ________in honor of __________ Average atmospheric pressure at sea level at 0°C is __________, or _________ Atmospheres: ___________is defined as being exactly equivalent to ___________

More about Units The SI unit of measurement for pressure is the ___________. _______________is the pressure exerted by a force of _____________acting on an area of ____________________ Usually expressed as ______________ _________= ________________

STP ___________= standard temperature and pressure STP has conditions of exactly ______and _________of pressure.

Dalton’s Law of Partial Pressures The pressure of each __________gas in a mixture of gases is called the ________ pressure of that gas. _________________states that the total pressure of a gas mixture is the sum of the partial pressures of the component gases ______________________________

Problem 1 A mixture of O2, CO2, and N2 has a total pressure of 0.97 atm. What is the partial pressure of O2 if the partial pressure of CO2 is 0.70 atm and the partial pressure of N2 is 0.12 atm?

Problem 2 Find the total pressure for a mixture that contains four gases with partial pressure of 5.00 kPa, 4.56 kPa, 3.02 kPa, and 1.20 kPa

Water Displacement Gas can be collected by water ____________, but some water _______ will be present The _____pressure will be the ____of the ______pressures of the gas collected and partial pressure of water _________ The partial pressure of water vapor is found on a table (dependent on temperature).

Gas Collected by Water Displacement Pgas = Patm – Pwater vapor

Problem 3 O2(g),from the decomposition of KClO3, was collected by water displacement. The barometric (atmospheric) pressure and the temperature during the experiment were 97.5 kPa and 20.0° C. What was the partial pressure of the O2 collected?