Describe how the plum pudding model of the atom was replaced by the nuclear model.
24 marks
Describe how sodium and chlorine atoms form an ionic compound. You may use dot-and-cross diagrams.
32 marks
Calculate the relative formula mass (Mr) of CaCO₃. (Relative atomic masses: Ca = 40, C = 12, O = 16)
43 marks
In paper chromatography, a spot moved 3.6 cm and the solvent moved 8.0 cm. Calculate the Rf value and explain how it could identify the substance.
56 marks
Describe how to prepare a pure, dry sample of copper(II) sulfate crystals from copper(II) oxide and dilute sulfuric acid.
64 marks
Predict the products at each electrode in the electrolysis of copper(II) chloride solution and write the half equation at the cathode.
74 marks
Explain how iron is extracted from iron(III) oxide in a blast furnace and why carbon can be used.
83 marks
Explain what is meant by dynamic equilibrium.
93 marks
An atom of potassium has mass number 39 and atomic number 19. Give the numbers of protons, neutrons and electrons.
103 marks
Explain why sodium chloride has a high melting point and conducts electricity when molten but not when solid.
112 marks
Calculate the relative formula mass (Mr) of Mg(OH)₂. (Relative atomic masses: Mg = 24, O = 16, H = 1)
123 marks
In paper chromatography, a spot moved 2.1 cm and the solvent moved 7.0 cm. Calculate the Rf value and explain how it could identify the substance.
133 marks
Explain the difference between a strong acid and a weak acid.
144 marks
Explain the products of electrolysis of sodium chloride solution (brine).
153 marks
Explain why aluminium is extracted by electrolysis rather than reduction with carbon.
164 marks
N₂ + 3H₂ ⇌ 2NH₃ (forward reaction exothermic). Explain the effect on the yield of ammonia of increasing pressure and increasing temperature.
172 marks
An element has two isotopes: mass 35 (75%) and mass 37 (25%). Calculate its relative atomic mass.
183 marks
Explain why methane has a low boiling point.
191 mark
What is the pH of a neutral solution?
Finished?
Answer every question to finish (19 left), or finish when the time’s up.
Score 0 / 60 · 0 of 19 marked
This paper is written by Plasmo in the style of the Edexcel GCSE Combined Science exam. It is not a past paper and is not produced or endorsed by the exam board.