The following table gives information about six substances.
Which substance could have a macromolecular structure, similar to that of silicon(IV) oxide?
Which substances are solids at room temperature?
Which substance could be a metal?
Which substance could be aqueous sodium chloride?
Which substance is an ionic compound?
Which substances are liquids at room temperature?
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Explain the following in terms of the kinetic particle theory.
The rate of most reactions increases at higher temperatures.
Explain the following in terms of the kinetic particle theory.
A liquid has a fixed volume but takes up the shape of the container. A gas takes up the shape of the container but it does not have a fixed volume.
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| substance | melting point / oC | boiling point / oC | electrical conductor at room temperature |
electrical conductor of substance dissolved in water |
| A | 961 | 2193 | good | does not dissolve |
| B | 113 | 444 | does not conduct | does not dissolve |
| C | 0 | 100 | very poor | very poor |
| D | 803 | 1465 | does not conduct | good |
| E | -5 to-1 | 102-105 | good | good |
| F | -8 | -6 | does not conduct | does not dissolve |
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Give the name of the process that occurs when a gas turns into a liquid.
1 markGive the name of the process that occurs when a solid turns into a gas without first forming a liquid.
Figure 1.2 shows a coloured crystal of cobalt(II) chloride is placed at the bottom of a beaker containing water.
After two days, the colour has spread throughout the water.
Figure 1.2
Explain these observations.
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Complete Table 1.1 about solids, liquids and gases.
| particle separation | particle arrangement | type of motion | |
| solid | regular | vibrate only | |
| liquid | some touching | random | |
| gas | apart | random |
The graph shows the change in temperature as a sample of a gas is cooled.
Name the change of state taking place between A and B.
A bottle of liquid perfume is left open at the front of a room.
After some time, the perfume is smelt at the back of the room.
Name the two physical processes taking place.
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This question is about bromine and compounds of bromine.
Use the kinetic particle model to describe the arrangement and type of motion of the molecules in:
Liquid bromine:
Bromine gas:
The graph shows how the volume of bromine gas changes with temperature. The pressure is kept constant.
Describe how the volume of the bromine gas changes with temperature.
Calcium melts at 839 °C and boils at 1484 °C.
What is the physical state of calcium at 1600 °C?
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This question is about chlorine and compounds of chlorine.
Use the kinetic particle model to describe the arrangement and type of motion of the molecules in:
Solid chlorine:
Chlorine gas:
1 markThe graph shows how the pressure of chlorine gas changes when temperature increases. The volume is kept constant.
Describe how the pressure of the chlorine gas changes with temperature.
The structure of compound S is shown.
The melting point of pure S is 159 °C.
The boiling point of pure S is 200 °C.
What is the physical state of pure S at 100 °C?
Explain your answer.
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Compound X is a colourless liquid at room temperature.
A sample of pure X was slowly heated from –5.0 °C, which is below its melting point, to 90 °C, which is above its boiling point. Its temperature is measured every minute and the results are represented on the graph.
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....................Compound X is a hydrocarbon. It contains 85.7% of carbon. The mass of one mole of X is 84 g.
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The diagram shows a heating curve for a sample of compound X.
Is X a solid, a liquid or a gas at room temperature, 20 °C?
Write an equation for the equilibrium which exists in region BC.
Name the change of state which occurs in region DE.
Explain how the curve shows that a pure sample of compound X was used.
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Ethanoic acid is a colourless liquid at room temperature. It has the typical acid properties and forms compounds called ethanoates.
A pure sample of ethanoic acid is slowly heated from 0 oC to 150 oC and its temperature is measured every minute. The results are represented on the graph below.
| C to D | E to F | |
|
separation (distance |
||
|
movement of particles |
random and slow | |
|
Can particles move apart to |
[5]
Complete the word equations for the reactions of ethanoic acid.
calcium + ethanoic acid → ................................................ + .........................................
................................................ + ethanoic acid → zinc ethanoate + water
Write the symbol equation for the reaction between ethanoic acid and sodium hydroxide.
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Element X can undergo the following physical changes.
Figure 1.1
Name each of the numbered physical changes shown in Figure 1.
One difference between boiling and evaporation is the rate at which the processes occur.
State one other difference between boiling and evaporation.
Element X can undergo the following physical changes.
Figure 1.1
Describe the separation, arrangement and motion of particles of element X in the solid state.
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This question is about iodine and compounds of iodine.
Use the kinetic particle model to describe the separation between the molecules and the type of motion of the molecules in:
Solid iodine:
Iodine gas:
The graph shows how the volume of iodine gas changes with pressure. The temperature is kept constant.
Describe how the volume of iodine gas changes with pressure.
Sulfur dioxide melts at –73 °C and boils at –10 °C.
What is the physical state of sulfur dioxide at –20 °C?
Explain your answer.
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Nitrogen dioxide, NO2, is a dark brown gas.
When nitrogen dioxide is cooled, it forms a yellow liquid and then pale yellow crystals.
These crystals are heated and the temperature is measured every minute. The following graph can be drawn.
[3]
[1]
Nitrogen dioxide and other oxides of nitrogen are formed in car engines.
[2]
[2]
Nitrogen dioxide, oxygen and water react to form dilute nitric acid.
Describe how lead(II) nitrate crystals could be prepared from dilute nitric acid and lead(II) oxide.
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Z is a covalent substance. In an experiment, a sample of pure solid Z was continually heated for 11 minutes.
The graph shows how the temperature of the sample of pure Z changed during the first 9 minutes.
What is the melting point of pure Z?
The sample of pure Z began to boil at 9 minutes. It was boiled for 2 minutes.
Use this information to sketch on the grid, in part (a), how the temperature of the sample of pure Z changed between 9 minutes and 11 minutes.
The sample of pure Z was continually heated between 2 minutes and 5 minutes.
Explain, in terms of attractive forces, why there was no increase in the temperature of the sample of pure Z between 2 minutes and 5 minutes.
Describe how the motion of particles of pure Z changed from 0 minutes to 2 minutes.
The experiment was repeated using a solid sample of impure Z.
Suggest the differences, if any, in the melting point and boiling point of the sample of impure Z compared to the sample of pure Z.
melting point:
boiling point:
A sample of pure Z was allowed to cool from 120 °C to 20 °C. The total time taken was 8 minutes.
Starting from point ×, sketch on the grid how the temperature of the sample of pure Z changed between 0 minutes and 8 minutes.
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