11. You have been given three compounds in unlabelled bottles, barium chloride, potassium chloride and strontium chloride, all of which are soluble in water. What test could you
use to determine the contents of each bottle? Explain your answer fully as well as the
results you expect to get? (2)

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?