MIDLE EAST TECHNICAL UNIVERSITY
NORTHERN CYPRUS CAMPUS
CHM 107 – Recitation 5
1. What would be the pressure on an underwater vessel at 1.5 km below sea level in atm? Take the density of seawater to be 1.12.
The vessel is 1.5 km below the surface, has a surface area of A. The volume of seawater above the vessel is V with a mass of m. Thus
2. A sample of a gas has a pressure of 75.2 mmHg in a 150-mL flask. If the gas is transferred to a 275-ml flask at the same temperature, what would be its pressure?
Since temperature is constant, . Therefore
Since volume has gone up, final pressure must be lower.
3. A newly discovered gas has a density of 2.39 at 23.0C and 715 mmHg. What is the molar mass of the gas?
4. In an experiment, a mixture of gasses occupied a volume of 3.00 L at a temperature of 22.5C. The mixture contained 14.0 g water vapour, 11.5 g oxygen and 37.3 g nitrogen. What is the total pressure of the gas. What are the partial pressures of the constituent gases?
. is given by
5. If you need to prepare 400.00 mL of H2 at 20.5C and 748 torr, what mass of zinc must be reacted with excess of HC(aq) to get it?
The balanced reaction is
LR is Zn since HCl is in excess.
Mole ratio is
Let number of grams of Zn required for reaction
6. Calculate the pressure of 15.g of methane gas in a 1.50-L container at 40C, using van der Waals’ equation and compare it with the ideal gas pressure. For methane,
Making pressure the subject of the formula, we have
Pressure calculated from the ideal gas equation, which should be higher, is