Calculate the relative formula mass (Mr) of CaCO₃. (Relative atomic masses: Ca = 40, C = 12, O = 16)
From Paper 9 (Chemistry), Higher
46 marks
Describe how to prepare a pure, dry sample of copper(II) sulfate crystals from copper(II) oxide and dilute sulfuric acid.
From Paper 9 (Chemistry), Higher
54 marks
Predict the products at each electrode in the electrolysis of copper(II) chloride solution and write the half equation at the cathode.
From Paper 9 (Chemistry), Higher
63 marks
Explain the difference between exothermic and endothermic reactions, with an example of each.
From Paper 9 (Chemistry), Higher
92 marks
Calculate the relative formula mass (Mr) of Mg(OH)₂. (Relative atomic masses: Mg = 24, O = 16, H = 1)
From Paper 9 (Chemistry), Higher
103 marks
Explain the difference between a strong acid and a weak acid.
From Paper 9 (Chemistry), Higher
114 marks
Explain the products of electrolysis of sodium chloride solution (brine).
From Paper 9 (Chemistry), Higher
124 marks
Use the bond energies (kJ/mol) H–H 436, Cl–Cl 243, H–Cl 432 to calculate the energy change for H₂ + Cl₂ → 2HCl.
From Paper 9 (Chemistry), Higher
152 marks
Calculate the relative formula mass (Mr) of H₂SO₄. (Relative atomic masses: H = 1, S = 32, O = 16)
From Paper 9 (Chemistry), Higher
162 marks
The pH of an acid changes from 2 to 4. By what factor has the hydrogen ion concentration changed?
From Paper 9 (Chemistry), Higher
173 marks
Explain why ionic compounds must be molten or dissolved to be electrolysed.
From Paper 9 (Chemistry), Higher
184 marks
Use the bond energies (kJ/mol) H–H 436, O=O 498, O–H 464 to calculate the energy change for 2H₂ + O₂ → 2H₂O.
Score 0 / 39 · 0 of 12 marked
This paper is written by Plasmo in the style of the OCR GCSE Combined Science exam. It is not a past paper and is not produced or endorsed by the exam board.