Types of chemical reactionIB MYP Chemistry: Mind map

Exam questions on Types of chemical reaction

1. A teacher in Ghana heats green copper(II) carbonate powder, CuCO₃, in a test tube. The powder turns black as copper(II) oxide forms, and a gas that turns limewater milky is given off.
   Explain what is meant by thermal decomposition, and describe how the mass of the solid in the test tube changes.2 marks
2. A metalworker in Peru places a clean iron nail in blue copper(II) sulfate solution. After some minutes the nail is coated with a brown solid and the blue solution fades to pale green as iron(II) sulfate forms.
   Write the balanced symbol equation, with state symbols, for the reaction.2 marks
3. A student tests three metals, magnesium, zinc and copper. She places a strip of each metal into separate solutions of the sulfates of the other two metals and records what happens. Magnesium in zinc sulfate solution: a grey coating forms. Magnesium in copper(II) sulfate solution: a brown coating forms and the blue colour fades. Zinc in copper(II) sulfate solution: a brown coating forms and the blue colour fades. Zinc in magnesium sulfate solution: no change. Copper in zinc sulfate solution: no change. Copper in magnesium sulfate solution: no change. Each test used the same volume of solution at room temperature.
   State a testable hypothesis for the student's investigation, give a scientific reason, and identify the independent variable.3 marks