Question

Topic: Practice exercise on gas laws. You must write the equation you are using to solve the exercise.

2. An unknown gas occupies an initial volume of 0.256 L when its temperature equals 121ºC. What will be the final volume if the temperature drops to 25ºC?

3. A sample of a gas has an initial pressure equal to 744 mmHg when its initial temperature is 22ºC. What is the final temperature in degrees Celsius if the pressure increases to 766 mmHg?

4. A diver inhaled 50.0 mL of compressed air from his tank under the sea, which was at 3.00 atm pressure and 8ºC temperature. What is the final pressure in atmospheres (atm) if the gas in the lungs expands to 150.0 mL and the body temperature is 37ºC?

5. A container contains a mixture of the oxygen, nitrogen and helium gases. All these gases exert a total pressure in the container equal to 925 Torr. The partial pressure of oxygen is 425 Torr and that of helium is 75 Torr. What is the partial pressure of nitrogen in the mixture?

Answer 1

Ideal gas equation PV-nRT P= Pressure V. Volume u no of mole R = gas constant O'C = 273k Ta temperahan Charles law, Volume of fixed amount of gas is directly proportional to its absolute temperature at constant pressure - V&T V = V2 Ti Tz V = 0.2561 T1 = 121°C -121 +213=394 K 12 = ? T2= 25°C= 25+273-218k V2= V.T2 = 0.256x298 -0.1946 394 e Gay Lussie's law, fт Ti Tz P = 744 mmily T = 22.2= 22+2732 295k P2 = 766 marts T2=2

744 - 766 295 Ta T2= 295x766 & 303.7k 744 74 303.7 273= 50.76 30² 6 PV = P V₂ ( Combined gas laws) P = 3.00alm V = 500ml Ti= 8C= 8+273-28 1K PA ? V2 = 1500ml T2= 376= 37+272 = 3 lok P₂ H P V Tz , 3x50 x 310 TV 2810 150 1.00 alum » Daltons law of Pastral pressure. Total = Pop + PN + Pne (at const T) PN 2 - Py -( POL + Pue) 925-(425+ 15) 925-500 - 425 torr