A laboratory bioreactor uses a small, high-pressure carbon dioxide cylinder to maintain a carbonated environment for cell culture.
The volume of the high-pressure cylinder is 15 cm315\text{ cm}^315 cm3.
The initial pressure of the gas inside the cylinder is 16000 kPa16000\text{ kPa}16000 kPa.
When the valve is opened, the gas expands into the headspace above the liquid culture medium.
The gas expands to a total volume of 480 cm3480\text{ cm}^3480 cm3.
Calculate the new pressure of the gas, assuming the temperature remains constant during this initial expansion.
As the gas expands into the headspace, its temperature decreases. Using ideas about molecules, explain how this temperature decrease affects the pressure of the gas.
Some of the carbon dioxide gas molecules dissolve into the culture medium. Suggest how this affects the pressure of the gas in the headspace and explain your answer.
When a liquid sample is drawn out of the bioreactor through a sampling valve, the pressure outside is less than the pressure inside. Suggest what happens to the dissolved gas as the liquid leaves the bioreactor.
51 exam-style questions on Edexcel IGCSE Physics Ideal gas molecules. Each one has a worked solution and a mark scheme showing where the marks go.