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Transcript
Unit 1 Practice Questions Questions 1-4 refer to the following: (A) (B) (C) (D) (E) Volume Temperature Density Pressure Mass 1. Is a quantity that allows one to calculate mass if density is known 2. Always varies with the number of molecules present in a sample of a particular substance 3. Can be expressed as kilograms per liter 4. Is a measure of the average kinetic energy of a substance’s molecules 1 Questions 1-3 refer to the following: (A) The rule is to add concentrated acid to water slowly (B) The rule is to add water to concentrated acid slowly (C) Carefully replace unused or excess chemicals into their properly labeled containers from which they came (D) Flush eyes with water at the eyewash fountain for at least 15 minutes (E) Dispose of chemicals in the proper places and following posted procedures. Do not return them to their original containers 1. The proper way to dilute a concentrated acid 2. How to properly dispose of chemicals not needed 3. What to do if a chemical splatters into your eyes 2 Questions 1-4 refer to the following: (A) (B) (C) (D) (E) Density A solid Volume Weight Matter 1. 2. 3. 4. Gives the mass per unit volume Has mass and a definite size and shape Gives the space occupied Has mass and occupies space 3 Questions 1-2 refer to the following: (A) (B) (C) (D) (E) A molecule A mixture of compounds An isotope An isomer An acid salt 1. The simplest unit of water that retains its properties 2. A commercial cake mix 4 II I If the density of a solid substance and its volume are both known, mass can be calculated For any substance, solid, liquid or gas, mass increases as volume increases BECAUSE For any substance, the relationship between the mass and volume varies directly with sample size BECAUSE Density represents mass per volume 5 II I A substance composed of two or more elements chemically combined is called a mixture A chemical change involves change in the composition and molecular structure of the reactants BECAUSE The properties of the constituents of a mixture are retained BECAUSE In a chemical reaction bonds are broken and new substances are formed 6 II I The burning of paper is a physical change Propane can be decomposed chemically BECAUSE When a chemical change occurs energy is either gained or lost by the reactants BECAUSE Propane is a compound made up of simpler elements 7 II I Methane is defined as a compound 1,100 grams is equal to 1.100 kilograms BECAUSE Methane can be broken down chemically BECAUSE To convert grams to kilograms one must divide by 100 8 II I It is possible to separate a watersoluble salt from a water-insoluble substance When diluting an acid, the acid is added to water BECAUSE BECAUSE The water-soluble substance will be caught in the filter paper, while the insoluble substance passes through filter paper The dilution of concentrated acid can release heat 9 II I The density of a sample of water is doubled by doubling its mass Iron is an element BECAUSE BECAUSE Compared to a gas, the molecules in a liquid are relatively far apart It cannot be broken into smaller units and retain its physical and chemical properties 10 Two solid objects are of equal volume, but object A has density = X, and object B has density = (0.5)X. Which of the following is true concerning objects A and B? (A) (B) (C) (D) (E) Objects A and B are of equal density Object B has twice the density of object A Objects A and B are of equal mass Object A has one half the mass of object B Object A has twice the mass of object B 11 The prefix centi- means (A) (B) (C) (D) (E) One thousand One thousandth One hundred One hundredth One millionth 12 A substance that can be further simplified by ordinary chemical means may be which of the following? I. An element or a compound II. A mixture or a compound III. An element or a mixture (A) (B) (C) (D) (E) I only II only III only I and II only I , II, and III 13 Which of the following would you not do in a laboratory setting? I. Pour acids and bases over a sink II. Wear goggles III. Heat a stoppered test tube (A) (B) (C) (D) (E) I only II only III only I and III only I , II, and III 14 A student conducted an experiment and obtained three values during three repetitive trials: 1.65, 1.68, 1.71. Later, the student discovered that the true value was 2.37. In contrast to the real value, the experimental results should be characterized as: (A) (B) (C) (D) (E) Not accurate and not precise Accurate but not precise Not accurate but precise Accurate and precise Accurate, precise, but unreliable 15 Which of the following is considered to be a dangerous procedure in the laboratory setting? (A) Pouring all liquids, especially acids and bases, over the sink (B) Wearing goggles (C) Pushing glass tubing, thermometers, or glass thistle tubes through a rubber cork (D) Pointing the mouth of a test tube that is being heated away from you and others (E) Knowing where the fire extinguisher and eyewash stations are located 16 The following statements were recorded while preparing carbon dioxide gas in the laboratory. Which one involves an interpretation of the data rather than an observation? (A) No liquid was transferred from the reaction bottle to the beaker. (B) The quantity of solid minerals decreased. (C) The cloudiness in the last bottle of limewater was caused by the product of the reaction of the colorless gas and the limewater. (D) The bubbles of gas rising from the mineral remained colorless throughout the experiment. (E) There was a 4oC rise in temperature in the reaction vessel during the experiment. 17 The property of matter that is independent of its surrounding conditions and position is (A) (B) (C) (D) (E) Volume Density Mass Weight State 18 Which substance can be decomposed chemically? (A) (B) (C) (D) (E) Ammonia Iron Neon Hydrogen Fluorine 19 A book is lifted off the floor and placed on a table that is one meter above the floor. The book has (A) (B) (C) (D) (E) Gained sound energy Lost chemical energy Gained potential energy Gained kinetic energy Lost nuclear energy 20 Which statement is incorrect regarding energy? (A) (B) (C) (D) (E) Energy can be given off in a reaction Energy can be gained in a reaction Energy cannot be created or destroyed Energy can take various forms Energy has mass and takes up space 21 Which type of change is different from the other four? (A) (B) (C) (D) (E) Baking a potato Rusting of an iron nail Burning a piece of paper Melting an ice cube Ignition of propane 22 Which of the following is not a physical property? (A) (B) (C) (D) (E) Color Phase Odor Boiling point Reactivity with oxygen 23 Which substance cannot be decomposed chemically? (A) (B) (C) (D) (E) Ammonia Tellurium Methane Water Lunch 24 Which sample represents a homogeneous mixture? (A) (B) (C) (D) (E) CH3OH (l) CH3OH (aq) CH3OH (g) CH3OH (s) None of the above 25 All of the following involve a chemical change EXCEPT (A) (B) (C) (D) The formation of HCl from H2 and Cl2 The color change when NO is exposed to air The formation of steam from burning H2 and O2 The solidification of vegetable oil at low temperatures (E) The odor of NH3 when NH4Cl is rubbed together with Ca(OH)2 powder 26 Which sample is a homogeneous mixture? (A) (B) (C) (D) (E) KI (aq) Fe (s) CO2 (g) NH3 (l) NaCl (s) 27 A student took a melting point of an organic compound four times. His work produced the following results: 97oC, 99oC, 100oC and 97oC. If the real melting point of the compound is 88oC, then his results can be summarized as (A) (B) (C) (D) (E) Both accurate and precise Neither accurate not precise Accurate but not precise Precise but not accurate extrapolated 28 In the metric system, the prefix kilo- means (A) (B) (C) (D) (E) 100 10-1 10-2 102 103 29 All of the following are compounds EXCEPT (A) (B) (C) (D) (E) Copper sulfate Carbon dioxide Washing soda Air lime 30 An example of a physical property is (A) (B) (C) (D) (E) Rusting Decay Souring Low melting point High heat of formation 31