Lab Exam Review Stations

Transcription

1 Chemistry Chapter 5 Lab Exam Review Stations Station : a) Place test tube containing lauric acid (C2H24O2) and a test tube containing sodium bicarbonate into water bath. Wait for one minute and record your observations in the table below. Substance Observations Ionic/Molecular? lauric acid Turns to colourless, molecular transparent liquid sodium bicarbonate No reaction ionic Run lauric acid test tube under cold water for 30 seconds then return both test tubes to test tube rack when you have completed your observations. Station 2: Chemical vs. Physical changes: Part : From the list below determine which are physical and which are chemical changes: Change Physical or Chemical? a. ripping paper Physical b. dissolving salt in water Physical c. milk going sour Chemical d. the baking of a cake Chemical e. ice melting Physical f. food being digested Chemical g. a candle burning Chemical

2 Station 3: Lewis Diagrams for Molecular Compounds Draw the Lewis dot diagram to show how the following compounds are bonded: CF 4 b) H 2O c) NH 3 d) C 2H 6

3 Station 4: In an experiment, 47 g of magnesium reacted with 82 g of hydrogen chloride to produce a gas and 75g of another substance. a) Is it possible for these results to comply with the Law of Conservation of mass? YES (yes/no) b) Explain your answer to part a) Gas is produced which escaped the container. The gas would make up the lost mass so that the reactant mass and product mass are then equal c) What gas is produced? Hydrogen Gas! d) How much of the gas is produced? 54g e) How could you test for this gas? Place a burning splint into a test tube containing the gas and you would hear a pop sound indicating hydrogen gas. f) Write a balanced chemical equation for this reaction. 2Mg + 2HCl! 2MgCl + H 2 (g) g) What type of reaction is this? Single Displacement Station 5: You are given an two aqueous solutions, A and B, when combined form H2O(aq) and NaCl(aq). You are given a selection of indicators to help you identify the two solutions as either acidic or basic. a) For each of the indicators shown below, describe what change, if any, occurs to them when they are added to an acid and a base. Indicator Change in acid Change in Base Methyl Orange Turns red Orange/yellow Blue Litmus Paper Turns red No change Red Litmus Paper No change Turns blue Bromothymol Blue Turns Yellow Blue Phenolphthalein No change pink Universal Indicator Red/Orange/Yellow Blue/Green/Purple

4 b) If solution A causes phenolphthalein to turn pink when added, Solution B is a Acid. Climate change Unit: Station 6: CO 2 Concentrations Graphical Analysis The graph below shows us atmospheric CO 2 concentrations collected over the past 65 years at the National Oceanic and Atmospheric Administration s (NOAA) Mauna Loa Observatory in Hawaii. This data is very valuable to climate scientists around the world, as it helps them to make predictions how Earth s climate will change in the future. Source: National Oceanic and Atmospheric Administration (NOAA) But what is this data telling us? Answer the following questions about the graphed data you see above. Questions. What is the overall trend (pattern) you see in CO 2 concentrations over time, from 958 to 2006? The overall trend is that CO 2 concentrations have been increasing over the past 65 years.

5 2. Why is there a zigzag pattern to the CO 2 concentration data? What could be causing this to occur? The zigzag pattern is associated with seasonal fluctuations in CO 2 concentrations. 3. Recalling what you know about greenhouse gases and the greenhouse effect, why is it important for scientists to maintain and analyze this chart over time? It is important for scientists to maintain and analyze this chart over time because CO 2 is a major greenhouse gas associated with global climate change. The greenhouse effect occurs because of the greenhouse gases in the Earth s atmosphere that help trap in heat to keep our planet warm enough for life to exist. When greenhouse gas levels become too high, the greenhouse effect becomes enhanced and global warming occurs. 4. What factors could be contributing to the overall trend (pattern) you see in the graphed data? Student answers will vary, but some factors could include burning fossil fuels, deforestation, and warming ocean temperatures 5. Make a prediction as to what you think will happen to CO 2 concentrations 0 years into the future. Explain your prediction. Student answer will vary, but should follow the current trend of increasing levels.

6 Station 7:. Below is a collection of data from 5 different sediment layers. Using the data in Table calculate the percentages of each species present in each layer using this equation: # of pollen type % of pollen type = total pollen collected 00 Table Sediment Layer Plant Species Color or Shape Code Number of each species pollen % of each species (4,500 ybp to present) western cedar western hemlock Douglas fir alder G A B D G- 24% A- 20% B-40% D-6% 2 (4,500 ybp to 9,500 ybp) Douglas fir oak mixed meadow species B J I B-2% J -2% I-76% 3 (9,500 to,200 ybp) Douglas fir grand fir alder B E D B- 28% E-20% D-52% H-28% 4 (,200 ybp to 5,000 ybp) lodgepole pine Engelmann spruce grand fir grasses & sedges alpine sagebrush H F E C K F-2% E-2% C-36% K-2% 2. What was the climate like during the time each sediment layer was deposited? Describe them below using Table 2 to help you. Make sure to comment on precipitation levels and temperature change. *NOTE: ybp = years before present* A. Sediment sample # (4,500 ybp to present) Temperate to cool, moist climate

7 B. Sediment sample #2 (9,500 ybp to 4,500 ybp) Warm, dry climate C. Sediment sample #3 (,200 ybp to 9,500 ybp) Warming to temperate climate conditions D. Sediment sample #4 (5,000 ybp to,200 ybp) Cool to cold sub-alpine/alpine (high altitude) climate conditions Table 2: Code Plant Species Climatic Characteristics A Western hemlock Principle dominant tree of many lowland, temperate sites. Require very moist, temperate conditions for growth B Douglas fir Prefers moderately cool to warm sites. Grows best under temperate, somewhat moist C Grasses & sedges conditions. These grasses and sedges are typically found in very cool alpine/sub-alpine meadow sites characterized by very cool summers, harsh winters, and short growing seasons. D Alder Widespread throughout the Pacific Northwest, prefers abundant water and can grow in cool climates. E Grand fir Grows in cool climates, but not as cold tolerant as trees found at higher altitudes. F Engelmann spruce Found in cold, usually sub-alpine sites. G Western cedar Found only in temperature, very moist climates. H I Lodgepole pine Mixed meadow species Found in areas of very cool climates typically growing on poor soils, often at high altitudes (above 3,500 feet) under the present climate. This pollen is from a mixture of plants common to warm meadowlands. Typically, these species grow in areas of warm summer temperatures and summer drought. J Oak Found in warm, temperate sites characterized by dry, warm summers. K Alpine sagebrush Woody, low growing shrub that s found only at high-altitude, cold sites.

8 SNC2D Station 8: Match the climate graph profiles to the 4 biomes shown below. Record the letternumber pairs below. They are not currently matched correctly(c: 4 marks) A _3_ C _2 B _4 D

9 Optics Unit: Station 9: M =!d i d o M = h i h o f = d i + d o. Use the following diagram and the equations above to answer the following questions. A thin lens with a focal length of 0 cm is positioned on the x-axis as shown below. An object of height 5 cm, represented by the arrow, is positioned 5 cm to the left of the lens. a. What type of lens is shown in the diagram above? Converging Lens or Concave Lens b. On the figure above, draw the necessary rays and sketch the image produced by the lens. c. Using the Thin Lens Equation, at what distance is the image located? (TI: mark) f = 0 cm do = 5 cm di =? f = d i + d o = d i f d o d i = 0 5 d i =

10 d i = d i = 30 cm d. Using the equations given, calculate the height of the image? (TI: mark) h! = 5 cm do = 5 cm d! = 30 cm d! d! = h! h! d! d! (h! ) = h! 30cm 5cm = h! 5cm!!"!"!"!" (5cm) = h! h! = -0 cm e. What is the magnification of this lens? (TI: mark) M = h! h! M = 0cm 5cm M = 2 f. What, if any, change will occur to the image as the object is moved towards the lens? (TI: mark) The closer the object gets to the lens, the larger the image will become. This will continue until the object is located directly over the focal point, F A, where no image will form. When the object is placed between F A and the lens then a virtual image will form that is on the same side of the lens as the object and the image will be larger than the object. Station 0:. Security System (4 marks) " Your challenge is to design the security system in an art gallery using laser light. A diagram of the art gallery is provided. You must meet the following conditions in your diagram: a. The laser may enter the art gallery from wherever you choose and in any direction you choose.

11 b. The laser must bounce off all of the reflectors shown in blue and finally reach the sensor marked in red. c. All angles of incidence and reflection must be labeled correctly, and all the normals must be shown. d. Please label your starting point where your laser will enter the art gallery " Record your answer on the diagram below and show the path of the laser. (C/A: 4 marks)