When gasses are collected by water displacement, there is always water vapor (gaseous water) present. The amount of water vapor present depends on the temperature. The greater the temperature, the more water vapor present (this quantity is called the vapor pressure). A 1.00 L volume of nitrogen gas measured at 290 K and 0.978 atm was collected at 290 K by water displacement. Use Dalton’s Law and the Ideal Gas Law to determine the number of moles of nitrogen gas that were collected. At 290 K, the vapor pressure of water is 14.59 Torr.

Definition Definition Law that is the combined form of Boyle's Law, Charles's Law, and Avogadro's Law. This law is obeyed by all ideal gas. Boyle's Law states that pressure is inversely proportional to volume. Charles's Law states that volume is in direct relation to temperature. Avogadro's Law shows that volume is in direct relation to the number of moles in the gas. The mathematical equation for the ideal gas law equation has been formulated by taking all the equations into account: PV=nRT Where P = pressure of the ideal gas V = volume of the ideal gas n = amount of ideal gas measured in moles R = universal gas constant and its value is 8.314 J.K-1mol-1 T = temperature