Singapore · SEABQ&A
ChemistryQ&A by dot point
A short Q&A bank for every Singapore Chemistry syllabus dot point. Each question and answer is drawn directly from our worked dot-point page, so you can scan key concepts before opening the long-form answer.
Acids, Bases and Salts
- Classify oxides as acidic, basic, amphoteric or neutral, and describe neutralisation as the reaction of hydrogen ions with hydroxide ions to form water4Q&A pairs
- Describe the preparation of soluble and insoluble salts, use solubility rules to choose the method, and carry out crystallisation and precipitation to obtain a pure salt3Q&A pairs
- Describe acids as sources of hydrogen ions and bases as proton acceptors, distinguish strong and weak acids, and describe the characteristic reactions of acids with metals, carbonates and bases4Q&A pairs
- Describe the pH scale as a measure of acidity and alkalinity, relate pH to hydrogen ion concentration, and use indicators and universal indicator to determine pH6Q&A pairs
Atomic Structure and Chemical Bonding
- Describe the structure of the atom in terms of protons, neutrons and electrons, define proton number and nucleon number, explain isotopes, and write the electronic configuration of the first twenty elements5Q&A pairs
- Describe covalent bonding as the sharing of electron pairs, draw dot-and-cross diagrams for simple molecules, and contrast the properties of simple molecular substances with giant covalent structures7Q&A pairs
- Describe ionic bonding as the transfer of electrons to form ions with noble-gas configurations, draw dot-and-cross diagrams, and relate the giant ionic lattice to the properties of ionic compounds5Q&A pairs
- Describe metallic bonding as a lattice of positive ions in a sea of delocalised electrons, relate it to the properties of metals, and explain why alloys are harder than pure metals4Q&A pairs
Electrolysis
- Predict the products of electrolysing aqueous solutions using the selective discharge rules based on ion reactivity and concentration, and write the electrode half-equations7Q&A pairs
- Describe electroplating and the purification of copper using reactive electrodes, explain the electrode reactions, and state industrial uses of electrolysis7Q&A pairs
- Describe electrolysis as the decomposition of a molten or aqueous ionic compound by electricity, identify the electrodes and the movement of ions, and predict the products of electrolysing a molten compound5Q&A pairs
Energetics, Rates of Reaction and Redox
- Explain the action of a catalyst in lowering activation energy, describe enzymes as biological catalysts, and interpret rate graphs of product formed against time4Q&A pairs
- Distinguish exothermic and endothermic reactions by energy change, draw and interpret energy profile diagrams, and explain energy change in terms of bond breaking and bond forming4Q&A pairs
- Define oxidation and reduction in terms of oxygen and electron transfer, identify oxidising and reducing agents, and use colour changes of common reagents to test for them5Q&A pairs
- Describe the effect of concentration, pressure, surface area and temperature on the rate of reaction, and explain these effects using collision theory8Q&A pairs
Experimental Chemistry and Separation Techniques
- Carry out and interpret qualitative analysis tests for common cations, anions and gases, describing the observations and the reagents used6Q&A pairs
- Name common laboratory apparatus and select the correct instrument to measure mass, volume of liquids and gases, time and temperature, reading each to an appropriate precision6Q&A pairs
- Describe paper chromatography, interpret a chromatogram to determine the number and identity of components, and calculate and use the Rf value5Q&A pairs
- Describe and select separation methods (filtration, crystallisation, simple and fractional distillation, use of a separating funnel) according to the properties of the substances, and test for purity using melting and boiling points3Q&A pairs
Metals and the Reactivity Series
- Relate the method of extracting a metal to its position in the reactivity series, describe the extraction of iron in the blast furnace, and explain reduction by carbon and by electrolysis4Q&A pairs
- Describe the conditions needed for iron to rust, explain methods of rust prevention including sacrificial protection, and relate the properties of steel and alloys to their uses5Q&A pairs
- Place metals in order of reactivity using their reactions with oxygen, water and acids, and use the reactivity series to predict displacement reactions of metals from their compounds5Q&A pairs
Organic Chemistry
- Describe the properties and reactions of ethanol and ethanoic acid, including the production of ethanol, the oxidation of ethanol to ethanoic acid, and the formation of an ester6Q&A pairs
- Describe the alkenes as unsaturated hydrocarbons, explain their addition reactions including the bromine test for unsaturation, and describe addition polymerisation7Q&A pairs
- Describe the alkanes as a homologous series of saturated hydrocarbons from crude oil, write their formulae and combustion equations, and explain complete and incomplete combustion8Q&A pairs
The Particulate Nature of Matter
- Name the changes of state and explain them using the particle model, interpret heating and cooling curves, and account for the flat portions at the melting and boiling points6Q&A pairs
- Describe and explain diffusion in gases and liquids, relate the rate of diffusion to the mass of the particles, and use diffusion as evidence for the kinetic particle model5Q&A pairs
- Distinguish between elements, compounds and mixtures, describe the difference between a compound and a mixture in terms of bonding and properties, and classify substances accordingly6Q&A pairs
- Describe the kinetic particle model of solids, liquids and gases and use it to explain their properties, including shape, volume, compressibility and the effect of temperature on particle motion5Q&A pairs
Stoichiometry and the Mole Concept
- Write formulae of ionic compounds from the charges on their ions, construct and balance chemical equations, and add state symbols7Q&A pairs
- Define concentration in mol per dm cubed and g per dm cubed, interconvert the two, and carry out titration calculations to find an unknown concentration6Q&A pairs
- Use mole ratios from balanced equations to calculate reacting masses and gas volumes, identify the limiting reagent, and calculate percentage yield6Q&A pairs
- Define relative atomic and molecular mass, the mole and the Avogadro constant, and interconvert mass, amount in moles and number of particles3Q&A pairs
The Periodic Table
- Describe the arrangement of elements in the Periodic Table by proton number into periods and groups, relate position to electronic configuration, and describe the metal to non-metal trend across a period4Q&A pairs
- Describe the properties and trends of Group I (the alkali metals) and Group VII (the halogens), including reactivity trends down each group and displacement reactions of the halogens6Q&A pairs
- Describe the characteristic properties of the transition elements and contrast them with Group I metals, and explain the unreactivity and uses of the noble gases in terms of full outer shells7Q&A pairs