Practise

Question bank

Original exam-style questions, mapped to your syllabus. Answers are checked for mathematical equivalence and every attempt updates your mastery.

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2730 questions · page 124 of 137 · choose a topic above to narrow them down

SA-OC-AL-0041 markL2 StandardCalculatorMaking ethanol

Balance:

\mathrm{C_2H_5OH+\_\,O_2\rightarrow2CO_2+3H_2O}

. What is the coefficient of

\mathrm{O_2}

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SA-OC-AL-0051 markL2 StandardCalculatorCarboxylic acids

Ethanol can be oxidised to

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SA-OC-AT-0051 markL2 StandardCalculatorElectron shells

An element has electronic configuration 2,8,7. Which group and period is it in?

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SA-OC-CB-0031 markL2 StandardCalculatorCovalent bonds

How many lone pairs of electrons are on the oxygen atom in a water molecule?

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SA-OC-CE-0031 markL2 StandardCalculatorElectroplating

Steel food cans are plated with tin mainly to

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SA-OC-CE-0041 markL2 StandardCalculatorElectroplating

During copper purification, the impure copper anode

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SA-OC-CE-0051 markL2 StandardCalculatorElectroplating

During electroplating with a silver anode, the concentration of silver ions in solution

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SA-OC-CH-0031 markL2 StandardCalculatorMethod

The solvent level must be below the baseline so that

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SA-OC-CH-0052 marksL2 StandardCalculatorRf values

The solvent front is

8.0

cm from the baseline. A dye has

R_f=0.25

. How far, in cm, did the dye move?

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SA-OC-CO-0041 markL2 StandardCalculatorPreventing rust

Galvanising coats iron with

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SA-OC-CO-0051 markL2 StandardCalculatorPreventing rust

A galvanised bucket is scratched but doesn't rust because

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SA-OC-DF-0041 markL2 StandardCalculatorRate of diffusion

Ammonia and hydrogen chloride diffuse towards each other in a

100

cm tube. The white ring forms

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SA-OC-EL-0031 markL2 StandardCalculatorAqueous electrolytes

The product at the cathode when concentrated aqueous sodium chloride is electrolysed is

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SA-OC-EL-0041 markL2 StandardCalculatorAqueous electrolytes

The product at the anode when dilute sulfuric acid is electrolysed is

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SA-OC-EL-0051 markL2 StandardCalculatorHalf-equations

Which half-equation shows what happens at the cathode in copper(II) sulfate solution?

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SA-OC-EN-0041 markL2 StandardCalculatorBond energies

Bond breaking is

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SA-OC-EN-0051 markL2 StandardCalculatorExo and endo

Activation energy is

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SA-OC-EQ-0031 markL2 StandardCalculatorLe Chatelier

\mathrm{N_2+3H_2\rightleftharpoons2NH_3}

. Increasing pressure

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SA-OC-EQ-0041 markL2 StandardCalculatorLe Chatelier

For an exothermic forward reaction, increasing temperature

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SA-OC-EQ-0051 markL2 StandardCalculatorLe Chatelier

Adding a catalyst to an equilibrium mixture

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