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245 questions found · practise this subject as a set Show 20 · 50 per page
#QuestionSubject and topicDifficulty
41 Which product forms at the cathode during electrolysis of aqueous sodium chloride with inert electrodes? Chemistry
Electrolysis		 Easy
42 How many faradays are needed to deposit 1 mol of aluminium from Al³⁺ ions? Chemistry
Electrolysis		 Easy
43 A current of 2 A is passed through CuSO₄ solution for 965 s. What mass of copper is deposited? (Cu = 63.5 g m… Chemistry
Electrolysis		 Medium
44 The same quantity of electricity that deposits 0.635 g of copper from Cu²⁺ is passed through AgNO₃ solution. … Chemistry
Electrolysis		 Hard
45 What happens at the anode when aqueous copper sulphate is electrolysed using copper electrodes? Chemistry
Electrolysis		 Medium
46 Which of these is a secondary (rechargeable) battery? Chemistry
Batteries, fuel cells and corrosion		 Easy
47 What is the overall reaction in a hydrogen–oxygen fuel cell? Chemistry
Batteries, fuel cells and corrosion		 Easy
48 Why does a mercury cell give a nearly constant voltage throughout its life? Chemistry
Batteries, fuel cells and corrosion		 Medium
49 During discharge of a lead storage battery, what is formed at both electrodes? Chemistry
Batteries, fuel cells and corrosion		 Medium
50 A scratched galvanised iron sheet still does not rust easily. What is the best explanation? Chemistry
Batteries, fuel cells and corrosion		 Hard
51 What are the usual units of the rate of a reaction in solution? Chemistry
Rate of reaction		 Easy
52 How is the instantaneous rate of a reaction found from a graph of reactant concentration against time? Chemistry
Rate of reaction		 Easy
53 In 2N₂O₅ → 4NO₂ + O₂, N₂O₅ disappears at 0.02 mol L⁻¹ s⁻¹. At what rate is NO₂ formed? Chemistry
Rate of reaction		 Medium
54 For 2HI(g) → H₂(g) + I₂(g), which expression correctly gives the rate of reaction? Chemistry
Rate of reaction		 Medium
55 Why does powdered marble react faster with dilute HCl than a single lump of the same mass? Chemistry
Rate of reaction		 Hard
56 Which statement about molecularity is correct? Chemistry
Rate law, order and molecularity		 Easy
57 The rate constant of a reaction has units of s⁻¹. What is the order of the reaction? Chemistry
Rate law, order and molecularity		 Easy
58 For 2NO + O₂ → 2NO₂, rate = k[NO]²[O₂]. By what factor does the rate change if [NO] is doubled while [O₂] is … Chemistry
Rate law, order and molecularity		 Medium
59 For a reaction A + B → products, doubling [A] alone doubles the rate, while doubling [B] alone has no effect … Chemistry
Rate law, order and molecularity		 Medium
60 For CHCl₃ + Cl₂ → CCl₄ + HCl, rate = k[CHCl₃][Cl₂]^½. What are the units of k? Chemistry
Rate law, order and molecularity		 Hard