4 November 2021 at 4:01 pm Chemistry practice questions 1. A cylinder contains helium gas at a pressure of 1470 kPa. When a quantity of helium gas which occupies a volume of 4.00L at a pressure of 14.7 kPa is withdrawn, the pressure in the tank drops to 1400 kPa. Calculate the volume of the tank. (Assume the temperature remains constant) 2. A bicycle tyre is filled with air to a pressure of 690 kPa at a temperature of 19 C. Riding the bike on asphalt on a hot day increases the temperature of the tyre to 58C. The volume of the tyre increases by 4.0%. What is the new pressure in the bicycle tyre? 3. A Scuba diver inflated a basketball to 10L at the surface and takes it on a dive to play underwater basketball. When the diver descends to a depth of 30m the volume of the ball has changed to 2.5L. Assume the surface pressure is equivalent to standard atmospheric pressure. Calculate the pressure in atmospheres experienced by the diver and the ball at a depth of 30m. 4. It is really unsafe to store a gas bottle in a car in summer. Temperatures in the cabin of a car on a 28 degree day can exceed 45 degrees. The pressure in a gas bottle is 152KPa at OC. What would the pressure be if the gas bottle was in the car on a 28 degree day? The volume of the gas bottle is 16.66L. 5. Potato chip bags are filled with nitrogen gas to preserve the freshness of the chips. A large bag of chips will hold a maximum volume of gas of 750 mL and will burst at this capacity. What temperature change in Celsius is required to burst a bag which has a starting volume of 700ml at 288K. 6. A compressed gas cylinder has an internal pressure of 13.7 MPa at 23C. The room in which the gas cylinder is stored catches on fire raising the temperature to 450C. What is the new pressure in the gas cylinder? (MPa is a mega pascal, mega x10^6) ....... 7. A 420 ml balloon is blown up at standard atmospheric pressure. When a thunderstorm passes over later in the day the atmospheric pressure changes to 700.0 mmHg. Calculate the new volume of the balloon in millilitres. 8. A container is used to collect an unknown volume of gas during an experiment at 0 degrees Celsius. The temperature of the gas is increased to 20 degrees Celsius, a more comfortable working temperature and was found to occupy a volume of 20L. What was the initial volume of gas collected. Assume the mass and pressure remained constant.