Definition. The partial pressure of a given gas is defined as the pressure exerted by that gas alone. For example, consider the gaseous mixture of oxygen, nitrogen, carbon dioxide, and water vapor, the typical mixture found in alveolar gas.
From Wikipedia, the free encyclopedia. Philadelphia County is a county located in the commonwealth of Pennsylvania. At the 2010 census, the population was 1,526,006, making it the most populous county in the state, despite being the second smallest county in the state by land area.
Donegal was part of Chester County until 1729, when Lancaster County was taken out of Chester County. During the late 1600s and early 1700s this entire area was virgin frontier territory administered from Philadelphia as part of the Proprietary given to William Penn on March 4, 1681 by King Charles II.