Mastery Quiz #1 Introduction to Chemistry & the Classification of Matter

Transcription

1 Mastery Quiz #1 Introduction to Chemistry & the Classification of Matter 1. Which of the following statements is false? a. A theory is a well tested explanation for a broad set of observations. b. A theory can be proven if substantial amounts of experimental data support it. c. A theory must be consistent with all known information. d. A theory can be used to predict the behavior of matter. 2. In what way were alchemists like modern chemists? a. They changed lead into gold. b. They used the submicroscopic realm to explain macroscopic phenomena. c. They focused on the concept of perfection, or Magnum Opus. d. They developed techniques for working with matter. 3. Which of the following traditional areas of chemistry studies the composition of matter? a. Physical chemistry b. Applied chemistry c. Analytical chemistry d. Biochemistry 4. Which of the following is the proper step to take if one s experimental results differ from that which would be expected given a widely accepted scientific theory? a. Report the results and conclude that the widely accepted theory is wrong. b. Report the results and indicate that experimental results are wrong. c. Report the results in a way that makes them jibe with the widely accepted theory. d. Report the results and note that they might require revision of the widely accepted theory. 5. A hypothesis is a. information obtained from an experiment. b. a proposed explanation for observations. c. a concise statement that summarizes the results of many experiments. d. a thoroughly tested model. 1

2 6. What is the proper classification of air? a. Heterogenous mixture b. Compound c. Homogenous mixture d. Cannot be classified because the air is made up of many different types of matter. 7. Two samples of a given substance should have identical properties, but are likely to have different properties. a. Physical, chemical b. Chemical, physical c. Extensive, intensive d. Intensive, extensive 8. When liquid nitrogen is exposed to room temperature it immediately boils. This is an example of what? a. Chemical change b. Change of phase c. Precipitation d. Extensive change 9. Which of the following is an example of a pure substance? a. Sodium sulfate b. Salt water c. Brass d. Barium chloride dihydrate 10. What macroscopic description depicts the liquid phase of matter? a. Definite shape and definite volume b. Definite shape and indefinite volume c. Indefinite shape and definite volume d. Indefinite shape and indefinite volume 2

3 11. Which submicroscopic explanation best explains why vapors are amorphous and have a changing volume? a. Particles are spread far apart and can therefore move randomly at high velocities. b. Particles are tightly packed such that energy can be transferred from particle to particle rather quickly. c. Particles are loosely packed but ordered such that they can take on any shape without changing the amount of space they collectively occupy. d. Current instruments do not permit chemists to describe accurately vapors at the submicroscopic level. 12. Which of the following best describes the type of knowledge gained from using the scientific method? a. Perfect b. Unbiased c. Tentative d. Untrustworthy 13. Experiments are designed to systematically change. a. Control variables b. Dependent variables c. Extrinsic variables d. Independent variables 14. It is a fact that the amount of energy, under certain conditions, is always observed to be equal to the product of the mass and squared speed of light. This phenomenon can best be described as what? a. A scientific law b. A qualitative observation c. A widely accepted theory d. A well tested hypothesis 15. What is meant when scientists refer to chemistry as the central science? a. Chemistry is the last remaining geocentric science. b. Chemistry studies carbon, which is the most commonly studied element in all sciences. c. Chemistry was the first science to adopt heliocentricity as an explanation for the earth s orbit. d. All sciences involve studying some aspect of matter, which is the topic of chemistry. 3

4 16. Which of the following fields of chemistry tend to study matter relevant to living things? I. Organic chemistry II. Inorganic chemistry III. Biochemistry a. I only b. II and III only c. I and III only d. I, II, and III 17. What would be the best way to obtain a sample of pure water from wet sand at a beach? a. Filtration then distillation b. Distillation then filtration c. Filtration only d. Distillation only 18. Applied chemistry refers to chemistry done with the goal of addressing real world problems. Which of the following most likely can be considered applied chemistry? a. Research on the carbon emissions of automobiles b. Research on the way medicines react with cancer cells c. Research on how exposure to undetonated nuclear weapons affects humans reproductive systems d. Each of the above are equally likely to be considered applied chemistry. 19. Which of the following was not a goal of practical Alchemists? a. Finding a universal solvent b. Constructing, deconstructing, and reconstructing matter c. Going through Magnum Opus d. Converting cheap metals into gold 20. If one comes across a sample of unknown matter and has narrowed the classification of the sample to either a homogenous mixture or a pure substance, then what must be true about the sample? a. The sample has a uniform appearance. b. It is impossible to say because homogenous mixtures and pure substances are completely unalike. c. The sample has multiple, visible layers. d. The sample is not an element. 4

5 21. When sodium a shiny, explosive metal and chlorine a poisonous gas come into contact, table salt is formed. What best explains why? a. The chemicals change physically. b. The chemicals change chemically. c. The chemicals change intensively. d. The chemicals change extensively. 22. Which method is the best approach to separating components that have retained their own chemical identities within a sample of matter that has a uniform appearance? a. Decomposition b. Filtration c. Sublimation d. Distillation 23. What would be the best classification of the un separated sample of matter described in #21? a. Solution b. Element c. Compound d. Heterogenous mixture 24. Salt and sugar both dissolve in water while retaining their chemical identities. Salt conducts electricity when dissolved, but sugar does not. What type of property is this? a. Chemical b. Extensive c. Physical d. Intensive 25. Plasma is a phase of matter very similar to gas. Which of the following distinguishes plasma from gas? a. The particles of plasma are electrically charged, or ionized. b. The particles of plasma are spaced relatively far apart. c. The particles of plasma can travel with high velocities. d. The particles spacing permits plasma to change easily the amount of space it occupies. 5