IGCSE Chemistry Mock Exam Questions and

IGCSE Chemistry Mock Exam Questions and Verified Answers, 100% Guarantee Pass (Latest 2025) Iron ore - Correct Answers ✅Haematite, Fe2O3 and sand Steps of extraction of iron - Correct Answers ✅1. Filter ore with water

• Crush ore and mix with limestone (CaCO3) and coke and pour into furnace
• Hot air blasted through the furnace)
• Heat generated - C(s) + O2 ===> CO2
• CO2 reacts with more hot coke- CO2 + C===> 2CO (incomplete

combustion)

• CO reduces iron 3 oxide - Fe2O3 (s) + 3CO ===> 2Fe(l) + 3CO2
• Limestone decomposed by heat- CaCO3===> CaO (s) + CO2 (g)
• CaO reacts with sand forming slag(neutralision) - CaO + SiO2 ===>

CaSiO3 End results of extraction iron - Correct Answers ✅-Slag is trapped above molten iron -Iron obtained is pig iron (95% pure). It is very brittle due to high carbon content -Slag is for road construction Extraction of aluminum - Correct Answers ✅1. Bauxite purified to make alumina (Al2O3)

• Ore mixed with cryolite to reduce melting point and increase conductivity

Reaction at the cathode for aluminum - Correct Answers ✅4Al3+ +12e ===> 4Al (reduction) Aluminum sinks to the bottom as atoms are stable now 1 / 4

IGCSE Chemistry Mock Exam Questions and Verified Answers, 100% Guarantee Pass (Latest 2025) Reaction at the anode for aluminum - Correct Answers ✅6O2- -12e ===> 3O2 (oxidation) Anode gets eaten away as it's made of carbon Overall aluminium reaction - Correct Answers ✅2Al2O3(l) ===> 4Al + 3O2 Principle of electrolysis (molten electrolyte) - Correct Answers ✅At the cathode metal is formed At the anode non metal or gas forms Reactivity series acronymn - Correct Answers ✅Please stop calling me a cute zebra, I like her call (me) smart goat Extracting zinc - Correct Answers ✅1. Roast (reduce) zinc blende in air - ZnS +O2 = ZnO

• Zinc is reduced using coke and CO is formed

3.Nitrate ion - Correct Answers ✅NO3- Sulphate ion - Correct Answers ✅SO4 2- salt from insoluble base - Correct Answers ✅add excess base to the acid filter to remove any unreacted base that's been added heat solution or leave in warm place to evaporate the water, allowing crystals of the salt to form 2 / 4

IGCSE Chemistry Mock Exam Questions and Verified Answers, 100% Guarantee Pass (Latest 2025) salt from soluble base - Correct Answers ✅use an acid-base titration to find the exact volume of the soluble base that reacts with the acid mix these correct proportions, which will produce a solution of the salt and water only (as all the acid and base has reacted) warm solution to evaporate the water to leave crystals of the salt preparation of insoluble salts by precipitation - Correct Answers ✅formed as a precipitate, meaning it is a solid in the water/solution

to make:

mix two solutions filter to remove solid salt wash salt with distilled water leave salt to dry on filter paper (faster in oven) how to know which method to use for salts - Correct Answers ✅reactants

are soluble: titration

Insoluble base: add access of it

Soluble salts - Correct Answers ✅all sodium, potassium and ammonium salts all nitrates Chlorides except silver and lead Sulphates except barium, lead and calcium Insoluble salts - Correct Answers ✅all carbonates except potassium, sodium and ammonium. 3 / 4

IGCSE Chemistry Mock Exam Questions and Verified Answers, 100% Guarantee Pass (Latest 2025) Describe the properties of alkenes in terms of addition reactions - Correct

Answers ✅Generally:

Addition reactions Involves the removal of C=C double bond C=C is very reactive and can easily react to form -C-C- alkanes general molecular formula - Correct Answers ✅CnH2n+2 hydrocarbons - Correct Answers ✅Compounds composed of only carbon and hydrogen saturated - Correct Answers ✅single bonds only alkenes general molecular formula - Correct Answers ✅CnH2n cracking - Correct Answers ✅Hydrocarbons can be cracked to produce smaller, more useful molecules. This process involves heating the hydrocarbons to vaporise them.

The vapours are:

Either passed over a hot catalyst (silica or alumina) Mixed with steam and heated to a very high temperature (temperature in the range of 600-700˚C) so that thermal decomposition reactions can occur. The products of cracking include shorter chain alkanes and alkenes (or hydrogen) Distinguish between saturated and unsaturated hydrocarbons - Correct Answers ✅Saturated = contain no C=C double bonds e.g. alkanes Unsaturated hydrocarbons react with bromine in an addition reaction, decolourising it (orange to colourless)

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