Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
IGCSE CHEMISTRY
CHAPTER 7
| Question | Answer |
|---|---|
| What is the name of these biological catalysts? | Enzymes |
| Freezing does not kill the microbes. Suggest why freezing is still a very effective way of preserving food. | Reduces growth of microbes |
| Describe how the pea plant makes a sugar such as glucose. Name 4 points. | Photosynthesis Light / photochemical Chlorophyll / chloroplasts Carbon dioxide and water needed |
| Predict one physical and one chemical property. Caesium (Cs) | Physical property - soft / can be cut (with a knife) Chemical property - react with water (not steam) |
| Predict one physical and one chemical property. vanadium (V) | Physical property - PHYSICAL hard Chemical property - more than one oxidation state |
| Predict one physical and one chemical property. fluorine (F) | Physical property - colourless gas Chemical property - colourless gas |
| Zinc is extracted from an ore called zinc blende, which consists mainly of zinc sulfide, ZnS. The zinc sulfide in the ore is first converted into zinc oxide. Describe how zinc oxide is made from zinc sulfide. | Heat and in air |
| Explain why the zinc produced inside the furnace is a gas. Name 3 points. | Temperature (inside the furnace) is above 907 °C Temperature (inside the furnace) is above the boiling point (of zinc) 1000 °C is above the boiling point (of zinc); |
| State the name of the physical change for conversion of gaseous zinc into molten zinc | Condensing |
| Rusting of steel can be prevented by coating the steel with a layer of zinc. Explain in 2 points, in terms of electron transfer, why steel does not rust even if the layer of zinc is scratched so that the steel is exposed to air and water. | Zinc is more reactive than iron Zinc is higher in the reactivity series than iron |
| What types of substance cause potassium iodide solution to turn from colourless to brown? | Oxidant; |
| What types of substance cause acidified potassium manganate(VII) solution to turn from purple to colourless? | Reductant |
| Which ion in iron(II) chloride solution causes acidified potassium manganate(VII) solution to turn from purple to colourless? | Iron |
| Which ion in iron(II) chloride solution causes acidified potassium manganate(VII) solution to turn from purple to colourless? | Iron |
| The results of two separate reactions between excess calcium carbonate and hydrochloric acid. Explains the differences between the reactions | The same volume of more concentrated acid was used in the second reaction |
| The effect of temperature on the rate of the reaction between marble chips and hydrochloric acid can be investigated by measuring the production of carbon dioxide. Which item of equipment is not required for the investigation? | Condenser |
| What changes decreases the rate of the reaction between magnesium and dilute hydrochloric acid? Name 2 points. | Diluting the acid Using larger pieces of magnesium |
| A simple way of making bread includes Mixing flour with a small amount of yeast and some water to make a ‘dough’. Leaving the dough in a warm place for the yeast to act Which two factors affecting a reaction rate are involved in bread making? | Temperature Use of an enzyme |
| The rate of a reaction depends on temperature, concentration, particle size and catalysts. Name one statement that is not correct? | Higher concentration decreases the rate of reaction |
| Which changes decrease the rate of reaction between magnesium and air? | Using magnesium ribbon instead of powdered magnesium |
| In separate experiments, a catalyst is added to a reaction mixture and the temperature of the mixture is decreased. What are the two effects of these changes on the rate of the reaction? | Catalyst added faster Temperature decreased faster |
| Calcium carbonate reacts with hydrochloric acid to form carbon dioxide. Which two changes would slow this reaction down? | Decreasing the concentration of hydrochloric acid Decreasing the temperature |
| Which change does not increase the speed of reaction between zinc and hydrochloric acid? | Decreasing the temperature |
| Copper(II) carbonate reacts with dilute sulfuric acid. CuCO3(s) + H2SO4(aq) → CuSO4(aq) + CO2(g) + H2O(l) The speed of the reaction can be changed by varying the conditions. Which conditions would always increase the speed of this chemical reaction? | Increase the concentration of the reactants Increase the temperature |
| Which change does not increase the speed of reaction between zinc and hydrochloric acid? | Decreasing the temperature |
| Which does not increase the speed of a reaction? | Increasing the particle size of one of the reactants |
| Aluminium reacts with iron(III) oxide as shown. iron(III) oxide + aluminium → iron + aluminium oxide. Name one statement about this reaction? | Aluminium is oxidised |
| The element vanadium, V, forms several oxides. In which change is oxidation taking place? | V2O3 → V2O5 |
| The reaction between magnesium and carbon dioxide is represented by the following equation. 2Mg + CO2 → 2MgO + C Name one statement describes what happens in this reaction? | The carbon in carbon dioxide is reduced |
| Name the equation that the oxidation of the underlined compound occur? | Fe2O3 + 3CO → 2Fe + 3CO2 |
| When copper is heated in air a black coating forms on the copper. What happens to the copper in this reaction? | The copper gains oxygen |
| Name the equation that shows an oxidation reaction? | C + O2 → CO2 |
| Which change is an oxidation? | FeO to Fe2O3 |
| Name the statement describes what happens in the reaction shown? 2Mg + CO2 → 2MgO + C | Magnesium is oxidised and carbon dioxide is reduced |
| The element vanadium, V, forms several oxides. In which change is oxidation taking place? | V2O3 → V2O5 |
| Which reaction is lead(II) oxide, PbO, oxidised? | 2PbO + O2 → 2PbO2 |
| Iron is extracted from iron oxide using carbon monoxide as shown in the equation. iron oxide + carbon monoxide → iron + carbon dioxide What does the equation show? | Carbon monoxide is oxidised to carbon dioxide |
| The equations represent redox reactions. Which equation is the underlined substance acting as a reducing agent? | 3CO + Fe2O3 → 2Fe + 3CO2 |
| Which reaction is reversible? | CuSO4.5H2O → CuSO4 + 5H2O |
| Which reaction is not a reversible reaction? | Combustion of alkanes |
| The equation shows the formation of anhydrous copper(II) sulfate from hydrated copper(II) sulfate. CuSO4.5H2O Name two statements for this equation? | The (II) in the name copper(II) sulfate refers to the oxidation state of the metal. The reaction is reversible |
| Heating pink cobalt(II) chloride crystals forms a blue solid and steam. The blue solid turns pink when water is added. Describe the pink cobalt(II) chloride and the reaction? | pink cobalt(II) chloride is Hydrated The reaction is reversible |
| When pink crystals of cobalt(II) chloride are heated, steam is given off and the colour of the solid changes to blue. CoCl2.6H2O CoCl2 + 6H2O What happens when water is added to the blue solid? | Colour - Changes to pink Temperature decreases |
| Which reaction will result in a decrease in pH? | Adding citric acid to sodium hydrogen carbonate solution |
| When blue copper(II) sulfate is heated, a white solid and water are formed. The white solid turns blue and gives out heat when water is added to it.Describe the blue copper(II) sulfate and the reactions? | The blue copper sulfate is hydrated and the reaction can be reversed |
| The equation shows a reaction that is reversed by changing the conditions. forward reaction CuSO4.5H2O → CuSO4 + 5H2O How can the forward reaction be reversed? | By adding water |
| The experiment was repeated using 0.1 g of finely powdered manganese(IV) oxide. All the other variables were kept the same. On the axes opposite, sketch the graph that would be expected. Explain the shape of this graph | Steeper curve because of a faster rate Faster rate because of increased surface area |
| Describe how you could show that the catalyst, manganese(IV) oxide, was not used up in the reaction. Manganese(IV) oxide is insoluble in water. | Filter (and rinse / wash) Dry manganese (IV) oxide Weigh / measure mass manganese(IV) oxide after reaction The mass should be 0.1 g or unchanged. |
| Why is the reaction between finely powdered aluminium and air very fast? | Large / high surface area High collision rate / Collide more Many collisions (between oxygen molecules and aluminium atoms) |
| Explain why for most reactions the rate of reaction decreases with time | concentration of reactants decreases |
Created by:
Haridus Academy