Syllabus: Syllabus Cambridge IGCSE Chemistry 0620
Flashcard IGCSE Chemistry | Quizlet
Syllabus: Syllabus Cambridge IGCSE Chemistry 0620
1. Solder is an alloy of lead and tin. Alloys generally tend to have lower melting
points and lower electrical conductivity when compared to their constituent
metals (they do conduct electricity well). Alloys are also more expensive than
pure metals.
2. All ammonium salts behave as acids so they neutralise bases to form salt, water
and ammonia with a few exceptions. The exceptions are ammonium hydroxide
and ammonium carbonate as both behave as bases and neutralise acids.
3. Methane is a gaseous fuel. U235 is a fuel that does not use oxygen to produce
energy. Carbon dioxide cannot be used as fuel as it is fully oxidised and cannot
burn anymore.
4. Oxygen is used for welding and it is an exothermic process.
5. Adding Mg to HCl, Na to H2O and CaCl2 to H2O is exothermic.
6. Distillation is an endothermic process.
7. In any questions asking about if the volume will have an effect on the rate of
the reaction, think about it this way. If there are 60 molecules of HCl in 30cm3
of water, that means there are 2 molecules of HCl per cm3. If you double the
volume of the HCl, there will be 120 molecules of HCl in 6cm3 of water, which
also means that there will be 2 molecules of HCl per cm3. This proves that the
concentration is not affected by the volume and so it does not have an effect on
the rate of the reaction.
8. Hydration is always exothermic.
9. Breathing difficulties are not caused by acid rain. However, it is the cause of
erosion of statues, trees dying and pH of lakes lowering.
10. Nickel is a silver metal with a high melting point. Many of its compounds are
green.
11. Iron can be used to make cooking utensils.
12. Alloys are made by mixing molten metals together and allowing them to cool.
13. Mild steel is not resistant to corrosion.
14. Ethanol is obtained from the fermentation mixture by fractional distillation.
15. Diamond and graphite both have giant covalent structures. In silicon(IV) oxide,
silicon and oxygen atoms are joined together by covalent bonds throughout the
whole structure. Diamond and silicon(IV) oxide have similar structures.
,16. Methane is produced by the decomposition of vegetation and is also part of the
waste gases produced by animals.
17. Hydrogen is used as a fuel, because when hydrogen burns in the air to form
water, heat energy and electricity can be produced.
18. Stainless steel is harder and has more resistance to corrosion than iron.
19. Mild steel is used in machinery because it is strong.
20. Household water contains dissolved salts.
21. Sulphur occurs naturally as the element sulphur.
22. Coal contains sulphur. Sulphur dioxide causes respiratory problems and
damages limestone buildings.
23. For combustion of hydrocarbons, say steam is produced, not water.
24. The number of moles present in a certain volume is the same for any gas,
meaning that the number of atoms/ions/particles/molecules is the same.
25. Graphite has a giant covalent structure.
26. Lead is found in petrol, sulphur is found in coal and fossil fuels.
27. Rf values are calculated in cm.
28. Catalysts only increase the rate and have no say in the equilibrium yield of a
product.
29. Why do they keep saying there are delocalised electrons between “layers of
carbon atoms” in graphite? - In graphite, each carbon atom is only bonded to
three other carbon atoms within its layer, leaving one extra electron per carbon
atom which is not used in bonding; this "free" electron is considered
delocalized, meaning it can move freely between the layers of carbon atoms,
hence the phrase "delocalized electrons between layers of carbon atoms" in
graphite.
30. Pressure has no effect on the kinetic energy of gas molecules. Gas pressure is
due to the molecules colliding with the walls of the container. The average
kinetic energy of a gas particle is directly proportional to the temperature. An
increase in temperature increases the speed in which the gas molecules move
31. pH 9.3–10.5. Below this pH, it is colourless; above, it is blue. (Thymolphthalein)
32. The concentration of a reactant decreasing does not necessarily mean that the
speed of the reactant molecules decreases
33. If increasing the volume leads to a decrease in the concentration of a reactant,
the reaction rate may slow down. A lower concentration of reactants can result
in fewer collisions between reactant molecules, potentially slowing the
, formation of products. Consequently, the graph representing the amount of
product produced may have a shallower slope
34. Increasing the concentration of a reactant often leads to a steeper graph
representing the amount of product produced over time, and generally results
in more product being produced. This relationship holds true when the reaction
is dependent on the concentration of the reactant.
Uses of SO2:
Manufacture of sulfuric acid, bleach or making wood pulp or making paper, food or fruit
juice or wine preservative, fumigant or sterilising.
Uses of sulfuric acid: making fertilisers or pickling metals or making fibres or making
phosphoric acid/phosphates making dyes or making paints/pigments/dyes or making
paper, making plastics or making detergents or tanning leather or battery acid
Metallic Bonding: the electrostatic force of attraction between the positive ions in a
giant metallic lattice and a ‘sea’ of delocalised electrons.
Relative atomic mass (Ar): The average mass of the isotopes of an element compared to
1/12th of the mass of an atom of 12C
Relative molecular mass (Mr): The sum of the relative atomic masses. For ionic
compounds, we use relative formula mass (Mr).
Covalent bond: when a pair of electrons are shared between 2 atoms, leading to noble
gas electronic configuration.
The molecular formula of a compound is the number and type of different atoms in one
molecule. The actual number of atoms of each element in a compound.
The empirical formula of a compound is the simplest whole number ratio of the
different atoms or ions in a compound.
Moles, mol, is the unit of amount of substance and that one mole contains
6.02 × 1023 particles, e.g. atoms, ions, molecules; this number is the Avogadro constant.
Electrolysis: The decomposition of an ionic compound when molten or in aqueous
solution by the passage of an electric current.
Electrolyte: Ionic compound that is in aqueous/molten state and undergoes
electrolysis.
Electrode is a rod of metal or graphite through which an electric current flows into or
out of an electrolyte.
Uses of calcium carbonate: making steel or iron/ in a blast furnace/toothpaste/(making)
glass / building/ (making) cement/treating acidic rivers or lakes/chalk;
Flashcard IGCSE Chemistry | Quizlet
Syllabus: Syllabus Cambridge IGCSE Chemistry 0620
1. Solder is an alloy of lead and tin. Alloys generally tend to have lower melting
points and lower electrical conductivity when compared to their constituent
metals (they do conduct electricity well). Alloys are also more expensive than
pure metals.
2. All ammonium salts behave as acids so they neutralise bases to form salt, water
and ammonia with a few exceptions. The exceptions are ammonium hydroxide
and ammonium carbonate as both behave as bases and neutralise acids.
3. Methane is a gaseous fuel. U235 is a fuel that does not use oxygen to produce
energy. Carbon dioxide cannot be used as fuel as it is fully oxidised and cannot
burn anymore.
4. Oxygen is used for welding and it is an exothermic process.
5. Adding Mg to HCl, Na to H2O and CaCl2 to H2O is exothermic.
6. Distillation is an endothermic process.
7. In any questions asking about if the volume will have an effect on the rate of
the reaction, think about it this way. If there are 60 molecules of HCl in 30cm3
of water, that means there are 2 molecules of HCl per cm3. If you double the
volume of the HCl, there will be 120 molecules of HCl in 6cm3 of water, which
also means that there will be 2 molecules of HCl per cm3. This proves that the
concentration is not affected by the volume and so it does not have an effect on
the rate of the reaction.
8. Hydration is always exothermic.
9. Breathing difficulties are not caused by acid rain. However, it is the cause of
erosion of statues, trees dying and pH of lakes lowering.
10. Nickel is a silver metal with a high melting point. Many of its compounds are
green.
11. Iron can be used to make cooking utensils.
12. Alloys are made by mixing molten metals together and allowing them to cool.
13. Mild steel is not resistant to corrosion.
14. Ethanol is obtained from the fermentation mixture by fractional distillation.
15. Diamond and graphite both have giant covalent structures. In silicon(IV) oxide,
silicon and oxygen atoms are joined together by covalent bonds throughout the
whole structure. Diamond and silicon(IV) oxide have similar structures.
,16. Methane is produced by the decomposition of vegetation and is also part of the
waste gases produced by animals.
17. Hydrogen is used as a fuel, because when hydrogen burns in the air to form
water, heat energy and electricity can be produced.
18. Stainless steel is harder and has more resistance to corrosion than iron.
19. Mild steel is used in machinery because it is strong.
20. Household water contains dissolved salts.
21. Sulphur occurs naturally as the element sulphur.
22. Coal contains sulphur. Sulphur dioxide causes respiratory problems and
damages limestone buildings.
23. For combustion of hydrocarbons, say steam is produced, not water.
24. The number of moles present in a certain volume is the same for any gas,
meaning that the number of atoms/ions/particles/molecules is the same.
25. Graphite has a giant covalent structure.
26. Lead is found in petrol, sulphur is found in coal and fossil fuels.
27. Rf values are calculated in cm.
28. Catalysts only increase the rate and have no say in the equilibrium yield of a
product.
29. Why do they keep saying there are delocalised electrons between “layers of
carbon atoms” in graphite? - In graphite, each carbon atom is only bonded to
three other carbon atoms within its layer, leaving one extra electron per carbon
atom which is not used in bonding; this "free" electron is considered
delocalized, meaning it can move freely between the layers of carbon atoms,
hence the phrase "delocalized electrons between layers of carbon atoms" in
graphite.
30. Pressure has no effect on the kinetic energy of gas molecules. Gas pressure is
due to the molecules colliding with the walls of the container. The average
kinetic energy of a gas particle is directly proportional to the temperature. An
increase in temperature increases the speed in which the gas molecules move
31. pH 9.3–10.5. Below this pH, it is colourless; above, it is blue. (Thymolphthalein)
32. The concentration of a reactant decreasing does not necessarily mean that the
speed of the reactant molecules decreases
33. If increasing the volume leads to a decrease in the concentration of a reactant,
the reaction rate may slow down. A lower concentration of reactants can result
in fewer collisions between reactant molecules, potentially slowing the
, formation of products. Consequently, the graph representing the amount of
product produced may have a shallower slope
34. Increasing the concentration of a reactant often leads to a steeper graph
representing the amount of product produced over time, and generally results
in more product being produced. This relationship holds true when the reaction
is dependent on the concentration of the reactant.
Uses of SO2:
Manufacture of sulfuric acid, bleach or making wood pulp or making paper, food or fruit
juice or wine preservative, fumigant or sterilising.
Uses of sulfuric acid: making fertilisers or pickling metals or making fibres or making
phosphoric acid/phosphates making dyes or making paints/pigments/dyes or making
paper, making plastics or making detergents or tanning leather or battery acid
Metallic Bonding: the electrostatic force of attraction between the positive ions in a
giant metallic lattice and a ‘sea’ of delocalised electrons.
Relative atomic mass (Ar): The average mass of the isotopes of an element compared to
1/12th of the mass of an atom of 12C
Relative molecular mass (Mr): The sum of the relative atomic masses. For ionic
compounds, we use relative formula mass (Mr).
Covalent bond: when a pair of electrons are shared between 2 atoms, leading to noble
gas electronic configuration.
The molecular formula of a compound is the number and type of different atoms in one
molecule. The actual number of atoms of each element in a compound.
The empirical formula of a compound is the simplest whole number ratio of the
different atoms or ions in a compound.
Moles, mol, is the unit of amount of substance and that one mole contains
6.02 × 1023 particles, e.g. atoms, ions, molecules; this number is the Avogadro constant.
Electrolysis: The decomposition of an ionic compound when molten or in aqueous
solution by the passage of an electric current.
Electrolyte: Ionic compound that is in aqueous/molten state and undergoes
electrolysis.
Electrode is a rod of metal or graphite through which an electric current flows into or
out of an electrolyte.
Uses of calcium carbonate: making steel or iron/ in a blast furnace/toothpaste/(making)
glass / building/ (making) cement/treating acidic rivers or lakes/chalk;
