Chemistry Unit 1 Test Review

Transcription

1 1. Describe what you should do before beginning a lab activity. 2. Describe what you should do after completing a lab activity. 3. Describe how to correctly smell a chemical in the lab. 4. Describe the correct way to dilute an acid. 5. Describe the correct way to heat the contents of a test tube. 6. Mrs. Dyer studies the effects of temperature on the reaction of alka-seltzer and water in a beaker. She adds 1 whole tablet of alka-seltzer and 50 ml of 100 C water to a 100 ml beaker and times how long it takes the alkaseltzer tablet to disappear. To accurately test the effects of temperature, Mrs. Dyer should begin a second test with 1 whole tablet of alka-seltzer with which set of conditions? A. One half tablet of alka-seltzer and 50 ml of 100 C tap water added to a 100 ml beaker. B. One half tablet of alka-seltzer and 50 ml of 0 C tap water added to a 100 ml beaker. C. One whole tablet of alka-seltzer and 50 ml of 0 C tap water added to a 100 ml beaker. D. One whole tablet of alka-seltzer and 50 ml of 100 C tap water added to a 250 ml beaker. 7. Makayla works at the farmer s market after school. She notices that the tomatoes in container 1 have dark the same temperature. Her boss tells her that the tomatoes were all grown from the same plant variety. Lydia discovers, after testing the plants from which the tomatoes came, that although the same type of soil was used, the fertilizer used on the plant that grew the tomatoes in container 1 was generic fertilizer from the feed store, while the fertilizer used on the plant that grew the tomatoes in container 2 was Miracle-Gro fertilizer. What is the independent variable in this scenario? A. The presence of dark spots on the tomatoes B. The type of soil used to grow the tomato plants C. The type of plant used to grow the tomatoes D. The type of fertilizer that was used on the plants

2 8. Makayla works at the farmer s market after school. She notices that the tomatoes in container 1 have dark the same temperature. Her boss tells her that the tomatoes were all grown from the same plant variety. Makayla discovers, after testing the plants from which the tomatoes came, that although the same type of soil was used, the fertilizer used on the plant that grew the tomatoes in container 1 was generic fertilizer from the feed store, while the fertilizer used on the plant that grew the tomatoes in container 2 was Miracle-Gro fertilizer. What is the dependent variable in this scenario? A. The presence of dark spots on the tomatoes B. The type of soil used to grow the tomato plants C. The type of plant used to grow the tomatoes D. The type of fertilizer that was used on the plants 9. Makayla works at the farmer s market after school. She notices that the tomatoes in container 1 have dark the same temperature. Her boss tells her that the tomatoes were all grown from the same plant variety. Makayla discovers, after testing the plants from which the tomatoes came, that although the same type of soil was used, the fertilizer used on the plant that grew the tomatoes in container 1 was generic fertilizer from the feed store, while the fertilizer used on the plant that grew the tomatoes in container 2 was Miracle-Gro fertilizer. What is a constant variable in this scenario? A. The presence of dark spots on the tomatoes B. The type of soil used to grow the tomato plants C. The person who grew the plants D. The type of fertilizer that was used on the plants 10. Makayla works at the farmer s market after school. She notices that the tomatoes in container 1 have dark the same temperature. Her boss tells her that the tomatoes were all grown from the same plant variety. Makayla discovers, after testing the plants from which the tomatoes came, that although the same type of soil was used, the fertilizer used on the plant that grew the tomatoes in container 1 was generic fertilizer from the feed store, while the fertilizer used on the plant that grew the tomatoes in container 2 was Miracle-Gro fertilizer. Makayla conducted this study to most likely answer which question about the tomatoes she observed at the farmer s market? A. What role do genetics play in the condition of tomatoes that come from a plant? B. What type of soil will produce tomatoes that have fewer dark spots? C. How does the amount of light that a tomato is exposed to affect the number of dark spots present on the tomato? D. How does the type of fertilizer used affect the condition of tomatoes that come from a plant?

3 11. Mason is having trouble staying awake during class and decides to participate in a study to determine whether a certain new energy drink helps people stay awake longer. There are 50 volunteers, each of whom is assigned to 1 of 2 groups. Volunteers in Group 1 are given 100 ml of a drink that looks like the new energy drink, but is really just coca-cola, and volunteers in Group 2 are given 100 ml of a drink that contains coca-cola mixed with the new energy drink. Which group is the control group? A. The number of people who are in each group B. The amount of drink each group receives C. The group who receives coca-cola only D. The group who receives coca-cola mixed with the new energy drink 12. A student wants to determine whether concentration affects the rate at which peroxide reacts with dishwashing liquid. The student puts 20 ml of room temperature 3% peroxide in 100 ml beaker, adds 7 ml of dishwashing liquid, and stirs the mixture gently. Which treatment would be the best comparison for this experiment? A. Put 20 ml of room temperature 3% peroxide in a 250 ml beaker, add 7 ml of dishwashing liquid, and stir gently. B. Put 20 ml of room temperature 30% peroxide in a 100 ml beaker, add 7 ml of dishwashing liquid, and stir gently. C. Put 10 ml of room temperature 3% peroxide in a 100 ml beaker, add 7 ml of dishwashing liquid, and stir gently. D. Put 20 ml of room temperature 30% peroxide in a 250 ml beaker, add 7 ml of dishwashing liquid, and do not stir. 13. A lab student mixes 10 grams of compound X with 120 ml of compound Y. The reaction will be the slowest under which set of conditions? A. Concentration Grain Size (mm) Temperature ( C) 2% B. Concentration Grain Size Temperature (mm) ( C) 20% C. Concentration Grain Size Temperature (mm) ( C) 25% D. Concentration Grain Size Temperature (mm) ( C) 10%

4 14. Which of the reactions pictured below would you expect to have the slowest reaction rate and why? A. Case 3 because there are more molecules of A and B and therefore it will take longer for them to react. B. Case 2, because there are more molecules of A and B and therefore more collisions. C. Case 1, because there are fewer molecules, there will be fewer collisions between A and B. D. All of these will react at the same rate. 15. It takes longer for alka-seltzer tablets to disappear in cold water than in warm water? Why? A. There are fewer molecules of alka-seltzer when it s in cold water than when it s in warm water. B. The alka-seltzer particles are not as spread out in cold water, so the water can t get to the particles as quickly to react. C. The concentration of the alka-seltzer is more in the cold water, so the chunks react more slowly. D. The cold temperature causes the particles to move more slowly, causing fewer collisions between particles and, therefore, a slower reaction. 16. When you did the alka-seltzer experiment, you found that your data did not support your hypothesis. What did you do? A. Changed your data so that your hypothesis was correct. B. Throw your data out. C. Concluded that your hypothesis was correct and select only data from your experiment that supported your hypothesis. D. Concluded that your hypothesis was incorrect, explained why, and then developed a new hypothesis that you could test based upon your results from the experiment.

5 Which conclusion below is correct based upon the data provided? A. Mealworms prefer dry conditions over damp conditions. B. Mealworms prefer damp conditions over food. C. Mealworms prefer damp conditions over dry conditions. D. Mealworms have no preferences. According to the data above, which statement is correct? A. 30 day old Strain X has more colonies than new Strain Y on day 5. B. 30 day old Strain Y has more colonies than Strain X on day 2. C. New Strain Y has fewer colonies than 30 day old Strain X on day 2. D. 30 day old Strain Y grows better than New Strain X on days Which reaction above proceeds very quickly then reaches an equilibrium? A. Reaction I B. Reaction II C. Reaction III D. Reaction IV

6 20. Which of the following conclusions is most correct based upon the data provided from the experiment above? A. Zinc reduces enzyme activity the most. B. Lead reduces enzyme activity the least. C. Zinc is bad for enzymes. D. Some heavy metals improve enzyme activity.