Students compare two catalysts for the decomposition of hydrogen peroxide. Each trial lasts 60 s; the same solution volume and concentration are available.
Plan an investigation to compare the rates fairly and assess whether a catalyst is used up.
[6 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A faulty heater produces carbon monoxide. The gas cannot be reliably detected by sight or smell. A student suggests using visible soot as the only warning of danger.
Evaluate this suggestion and explain the health risk of carbon monoxide.
[4 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Chlorine atoms have electron arrangement 2,8,7. Iodine atoms have more occupied electron shells but also seven outer electrons.
.1
Explain why chlorine is more reactive than iodine.
[3 marks]
.2
Compare this trend with the reactivity trend down group 1.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Three noble gases have boiling points: helium −269 °C, neon −246 °C and argon −186 °C.
.1
Calculate the rise in boiling point from helium to argon.
[2 marks]
.2
Describe the trend and predict whether krypton, below argon, boils above or below −186 °C.
[2 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student writes the electron arrangement of calcium, atomic number 20, as 2,8,10.
.1
Explain the correction needed for a neutral calcium atom.
[3 marks]
.2
Explain one incorrect prediction that could follow from the student arrangement.
