Group 2: the alkaline earth metalsIB MYP Chemistry: Mind map

Exam questions on Group 2: the alkaline earth metals

1. A firework designer in Valencia uses magnesium powder to produce a brilliant white light in a display rocket. Magnesium is a Group 2 metal, and the powder burns in the oxygen of the air.
   Write the balanced symbol equation for magnesium burning in oxygen.2 marks
2. A class adds a small piece of calcium to cold water in a beaker containing universal indicator. The calcium sinks, fizzes steadily, and the water turns cloudy and then purple. In a second beaker, a clean strip of magnesium ribbon in cold water produces only a few tiny bubbles over several minutes.
   Explain why calcium reacts more vigorously with water than magnesium.2 marks
3. A student compares magnesium and calcium by reacting each with dilute hydrochloric acid and collecting the hydrogen in a gas syringe for 60 s. She uses the same mass of metal, 25 cm³ of the same acid and the same temperature, and repeats each test twice. Magnesium gave 16 cm³ and 20 cm³. Calcium gave 58 cm³ and 62 cm³. The magnesium was a ribbon strip and the calcium was small granules. Her hypothesis was that calcium is more reactive than magnesium.
   Calculate the mean volume of hydrogen for each metal and state whether the results support her hypothesis.3 marks