Chemistry 8 Chapter 7 Review Kinetic Molecular Theory 1. Define Mass The amount of matter in a substance or object.

Transcription

1 Chemistry 8 Chapter 7 Review Kinetic Molecular Theory 1. Define Mass The amount of matter in a substance or object. 2. Define Volume The amount of space taken up by a substance or object. 3. What are the 3 states of matter? Briefly describe how the particles are arranged in the 3 states. Remember to discuss the movement of the particles and the spaces between them. Solid: Close together and in a very ordered regular arrangement. Liquid: Still close together but slightly further apart (except water compared to ice). Now the particles are free to move around. Gas: Much further apart and moving much faster than the liquid state of the same substance. 4. In terms of the particles movement and spacing, what happens during the following phase changes a. Boiling On heating, when the liquid turns into a gas the particles move much faster and are a lot further apart. b. Solidification On cooling when a liquid turns into a solid, the moving particles become fixed in place and the spacing gets smaller (except in water where ice has a slightly bigger volume than water). 5. What is the formula to calculate density knowing the mass and the volume of an object? Density = Mass Volume The units of mass are usually grams and the volume in cm 3. Note: In a typical exam question the distances provided, which allow you to calculate the volume, will be in metres, so convert them to cm before calculating the volume 6. How does increasing the temperature affect the density of a substance? It may help you to think about the changes that occur in the quantities used in your formula in question 5 When substances are heated they generally expand so the volume increases. The mass stays the same so the ratio of mass to volume (density) must go down 7. How could you quickly show with a simple experiment that two liquids that do not mix have different densities? Place them in the same glass container, the less dense liquid will float on the more dense liquid. 8. How do you experimentally measure the volume of a regular shaped solid object? Measure the length, width and height and then multiply them together 9. How do you experimentally measure the volume of an irregular shaped solid object? Use the displacement method. Place a certain volume of water in a measuring cylinder. Add the irregular object and measure the new volume of the water with the object in it. Subtraction of the two volumes will give you the volume of the object.

2 Additional Material Laboratory procedures / The Bunsen Burner / WHMIS symbols 10. What is the correct sequence for the major components of a laboratory report Purpose, Materials, Procedure, Data (Results), Analysis, Conclusion 11. What is the difference between a qualitative and a quantitative observation? Just ask yourself if there is a number involved qualitative is just descriptive; quantitative (quantity) will have a number in the observation 12. To light a Bunsen burner you should Attach the tube to the gas tap. Close the air valve (on the barrel of the BB) Make sure the gas valve (bottom of the BB) is half open Turn on the gas and light the Bunsen 13. A Bunsen burner has two types of flame. The yellow flame that is produced when you light it and the hot, blue flame used to heat chemicals. How do you change the yellow flame into the blue flame? The hot flame needs lots of oxygen to burn the gas. So open the air valve (on the barrel of the BB) 14. The WHMIS symbols have key parts to them that help you remember which is which. For example the symbol for XX has a skull and cross bones in it. What distinguishing feature is in the symbol for the following a. Oxidizing material A large O with flames around it b. Flammable A flame with a maple leaf in the middle c. Compressed gas Looks like a gas cylinder d. Corrosive material A test tube pouring what looks like acid on a hand and a piece of metal

3 Chemistry 8 Chapter 10 Review The Role of the Water Cycle on Earth 1. Where is most of Earth s fresh water located? Frozen in ice 2. What fraction of the earth s water is available fresh water? About 1% 3. Name the physical processes that occur during the water cycle - when water goes from the ocean, to clouds, to rain, and back to the ocean. Water from the ocean is heated and it evaporates. As it rises the temperature goes down and the water vapor cools and condenses into clouds. If the drops of water are big enough they will fall as rain onto the land. Here the flow into rivers which eventually return the water to the sea. 4. A. Explain why mountains along the coast of British Columbia tend to receive more precipitation than the interior of the province. The wind in Vancouver is predominantly from the west off the Pacific Ocean. Above the ocean, water vapor forms as the ocean water is heated and it evaporates. This wet air is blown towards the land. The air must go up to go over the mountains and it cools and produces rain (see question 3 above). As the air is blown eastward into the interior it has lost most of its moisture on the coastal mountains so the interior will be drier. 5. How is ocean water different from fresh water? Give two differences. Salinity / density / different freezing point 6. What is the main chemical component of sea water Sodium chloride 7. Name two sources of the salts that occur in sea water Dissolved minerals in rocks / under sea volcanoes 8. Why does fresh water float on salt water? Salt water is denser than fresh water due to the dissolved salts. 9. What is run-off and why is it important? It is essential for filling the lakes, streams, and rivers that in turn help to keep the oceans filled with water so it has an important role in the water cycle. 10. Describe three ways to decrease run-off Make land flatter; Plant vegetation; Restrict development 11. What is a drainage basin An area of land on which precipitation falls and works its way into a common river 12. How are the terms porosity, aquifer, water table and ground water related. Write a brief paragraph illustrating the connection. Underground water is found in an aquifer a layer of rock that is porous and allows water to flow through it. A well is dug into the ground down to the water table where the water can be found.

4 13. Give an example of physical, chemical and biological weathering. Physical weathering: The gradual process of wearing down rock without changing its physical appearance. E.g. Rivers creating valleys over many years. Chemical weathering Breaking down of rock when its minerals react with chemical agents such as oxygen, carbon dioxide, water and acids. E.g. See question 14 below. Biological weathering Physical or chemical weathering caused by plants or animals. E.g. A tree root breaking through a rock 14. Briefly describe how caves form in limestone areas. Rainwater is naturally acidic due to dissolved CO 2. When the water comes into contact with any rock that contains calcium carbonate the acidic water dissolves the rocks at first forming small cracks and gaps and eventually the possibility of large underground caves 15. Valleys can be U shaper or V shaped why is this? Fast moving rivers carve V shaped valleys looks like a letter V. Glaciers are much wider and can carve out entire valleys and the have a U shaped cross section. 16. Describe / Draw See text book page 394 to 395 and explain the formation of each of the following geological features a. Arête b. Erratic Narrow ridge formed between two cirques A large boulder deposited on the ground by a glacier c. Cirque Bowl-shaped valley at the head of a glacier d. Esker Winding ridge of material deposited by a stream running under a glacier e. Fiord A narrow inlet of ocean between steep cliffs formed by glaciers. f. Moraine Ridge of rocky material deposited by a glacier. They can be found at the sides (lateral), middle when two glaciers meet (medial) and the end (terminal) g. Horn Pyramid shaped peak located between three cirques

5 17. How are waves generated Wind action; volcanic eruptions; landslides; underwater earthquakes (creates a tsunami) 18. How are tides generated Gravitational pull from the sun and the moon Chemistry 8 Chapter 11 Review Oceans control the Water Cycle 1. Define the following features found on the ocean floor a. Continental shelf The shallowest part of the continental margin that extends into the ocean from the shore b. Abyssal plane The wide, flat part of the ocean laying between the continental margins and mid-ocean ridges c. Submarine canyon A deep gully carved into the continental shelf or slope by turbidity currents d. Tectonic plates Large rock slabs of the Earth s crust and upper mantle that float on the molten magma. 2. Briefly explain how the following two undersea features are formed a. Mid-ocean ridge When two plates are pushed apart, the underlying magma oozes up into the empty space, solidifies and forms a chain of mountains b. Ocean Trench When an oceanic plate collides with continental plate, the denser oceanic plate is forced to slip under the continental plate. This process is called subduction and it results in an ocean trench. It is a long V shaped groove that marks the boundary between the two plates. They tend to form on the edge of the ocean basin 3. What are the causes of surface ocean currents? Three factors: Uneven heating of the atmosphere - winds, the spinning of the Earth on its axis, and the shape of the Earth s land masses 4. What are the causes of deep-water ocean currents? Here the two main influences are: water temperature and salinity. Cold water is denser, it sinks and moves along the ocean floor, moving large masses of water around. In a similar way, saltier water is denser and it also sinks. Salinity increases occur through evaporation and freezing 5. What is the connection between the Pacific Ocean and the climate of Vancouver The water in the Pacific Ocean has a high Heat Capacity and is therefore able to store a large amount of energy. Compared to a town in the interior with a similar latitude, this energy helps to keep Vancouver warmer in the winter and cooler in the summer