Chapter 1
Scientific Measurements
Multiple Choice Questions
1. A tentative explanation used to explain observed facts or laws is called
a. the scientific method.
b. a scientific law.
c. a theory.
d. a hypothesis.
e. an empirical fact.
Answer: d
Section 1.1
Difficulty Level: easy
2. A broad generalization based on the results of many experiments is called
a. the scientific method.
b. a scientific law.
c. a theory.
d. a hypothesis.
e. an empirical fact.
Answer: b
Section 1.1
Difficulty Level: medium
3. Which of the following is false?
a. Experiments can be used to show that a theory is somewhat limited in scope.
b. A hypothesis which has successfully withstood many tests eventually can become a theory.
c. In general, a theory can be proven to be absolutely true. d. In general, a theory cannot be proven to be absolutely true.
e. A theory is an explanation of general principles which has withstood repeated
testing.
Answer: c
Section 1.1
Difficulty Level: hard
4. A scientific law is
a. a tentative explanation for a set of observations that can be tested by further experimentation.
b. a statement describing a relationship between phenomena that is always the same under the same conditions.
c. a unifying principle that explains a body of facts and relations.
d. a model used to visualize the invisible.
e. a rule that sets the standard units of scientific values.
Answer: b
Section 1.1
Difficulty Level: hard
5. Which of the following gives the best description of what the scientific method is?
a. It is the process of carefully following the steps of a lab procedure.
b. It is the guidelines that are followed during laboratory measurements.
c. It is unifying principle that explains a body of facts and relations.
d. It is the process of making observations and then designing ways to evaluate or explain those observations.
e. It is a guidebook for laboratory techniques that is followed by all chemists.
Answer: d
Section 1.1
Difficulty Level: medium
6. An example of an element is
a. glucose, C6H12O6.
b. table salt, NaCl.
c. gold, Au.
d. an oxide of iron, Fe2O3.
e. limestone, CaCO3.
Answer: c
Section 1.2
Difficulty Level: easy
7. An example of an element is
a. ozone gas, O3.
b. water, H2O.
c. benzene, C6H6.
d. carbon dioxide gas, CO2.
e. ammonium nitrate, NH4NO3.
Answer: a
Section 1.2
Difficulty Level: easy
8. An example of a chemical compound is
a. iron metal, Fe.
b. brass, a solution of Cu and Zn.
c. ozone gas, O3.
d. sand.
e. table salt, NaCl.
Answer: e
Section 1.2
Difficulty Level: easy
9. An example of a chemical compound is
a. silver, Ag.
b. helium gas, He.
c. carbon dioxide gas, CO2.
d. mercury metal, Hg.
e. hydrogen gas, H2.
Answer: c
Section 1.2
Difficulty Level: easy
10. The two types of pure substances are
a. compounds and elements.
b. compounds and solutions.
c. elements and mixtures.
d. mixtures and solutions.
e. solutions and elements.
Answer: a
Section 1.2
Difficulty Level: medium
11. Which is an example of a chemical change?
a. Steam from the boiling water condenses on the ceiling.
b. The solid metal is heated until it melts.
c. The gas is cooled until it finally becomes a liquid.
d. A piece of paper burns in air with a smoky flame.
e. The table salt in the warehouse container had very large chunks in it.
Answer: d
Section 1.2
Difficulty Level: medium
12. Which is an example of a physical change?
a. The milk in the box left on the table becomes sour after a few days.
b. The bit of scrap metal dissolves when placed in the container of acid.
c. The gas is cooled until it finally becomes a liquid.
d. A piece of paper burns in air with a smoky flame.
e. Bubbles are seen on the egg shell after some vinegar is poured on it.
Answer: c
Section 1.2
Difficulty Level: medium
13. Which is an example of a physical change?
a. Water, when heated, forms steam.
b. Bleach turns hair yellow.
c. Sugar, when heated, becomes brown.
d. Milk turns sour over time.
e. Apples, when exposed to air, turn brown over time.
Answer: a
Section 1.2
Difficulty Level: medium
14. Which is an example of a chemical change?
a. The milk in the carton became frozen after the carton was accidentally placed in
the freezing compartment.
b. The bit of scrap metal was crushed by the heavy machine.
c. The gas was cooled until it eventually became a liquid.
d. The piece of paper was cut into many thin strips by the shredding machine.
e. Bubbles were seen on the egg shell after some vinegar was poured on it.
Answer: e
Section 1.2
Difficulty Level: medium
15. Which is an example of a physical change?
a. Steam from the boiling water condenses on the cooler part of the ceiling.
b. The crude metal ore was first heated then combined with pure oxygen gas to make
the oxide of the metal.
c. The chef made scrambled eggs for their breakfast.
d. A piece of paper burns in air with a smoky flame.
e. The table salt in the warehouse was used to make some of the polymeric material.
Answer: a
Section 1.2
Difficulty Level: medium
16. Which is an example of a physical change?
a. Water freezing at 0°C.
b. Burning gasoline.
c. A potato turns brown after being cut open and left out.
d. Heating magnesium metal causes it to turn into an off white solid.
e. When exposed to certain metals hydrogen peroxide will bubble and fizz.
Answer: a
Section 1.2
Difficulty Level: medium
17. Which is an example of both a physical and a chemical change?
a. The milk in the carton became frozen after the carton was accidentally placed in
the freezing compartment overnight.
b. The bit of scrap metal was removed to the junkyard after being crushed by the heavy machine.
c. The gas was collected in a flask and cooled until it eventually became a liquid.
d. The old parchment became dry after being placed in the hot oven, but then was charred since it was not removed in the specified time.
e. Bubbles were seen on the egg shell when the vinegar was poured on it.
Answer: d
Section 1.2
Difficulty Level: hard
18. Which is an example of both a physical and a chemical change?
a. The milk in the carton became frozen because the carton was accidentally placed
in the freezing compartment overnight.
b. The bit of scrap metal was removed to the junkyard after being crushed by the heavy machine.
c. The gas was collected in a flask and cooled until it eventually became a liquid.
d. The old parchment became dry when it was placed in the warm oven for ten minutes.
e. Bubbles were seen on the egg shell soon after a sample of the vinegar was poured on it.
Answer: e
Section 1.2
Difficulty Level: hard
19. An example of a chemical change is
a. the mixing of glucose with table salt.
b. the dissolving of table salt in water.
c. sodium combining with chlorine to form table salt.
d. mixing rust with sand.
e. mixing chalk with helium in a balloon.
Answer: c
Section 1.2
Difficulty Level: easy
20. Which of the examples below is a chemical change?
a. A bottle of wine completely evaporates in two weeks.
b. Bleach changes the color of the stain on the white shirt.
c. The ‘dry ice’ (solid CO2) changes to vapor.
d. Bubbles form in the water when He gas is blown into the water.
e. These are all examples of chemical change.
Answer: b
Section 1.2
Difficulty Level: easy
21. Which is an example of a chemical change?
a. the separation of air into oxygen, nitrogen, and other components
b. the separation of a compound into its elements
c. the separation of gases from liquids
d. the separation of a mixture into its components
e. the separation of solids from liquids
Answer: b
Section 1.2
Difficulty Level: easy
22. Which one of the following is a physical change?
a. When ignited with a match in open air, paper burns.
b. In cold weather, water condenses on the inside surface of single pane windows.
c. When treated with bleach, some dyed fabrics change color.
d. When heated strongly, sugar turns dark brown.
e. Grape juice left in an open unrefrigerated container turns sour.
Answer: b
Section 1.2
Difficulty Level: easy
23. Which is an example of a physical change?
a. The ‘dry ice’ (solid CO2) changes to vapor.
b. A bottle of wine turns into vinegar in a few months.
c. Bleach changes the color of the stain on the white shirt.
d. Bubbles form on the egg shell when it is placed in the vinegar.
e. A portion of the figurine dissolves after being placed in the container of acid.
Answer: a
Section 1.2
Difficulty Level: easy
24. Which one of the following examples does not involve a chemical change?
a. A fish that is left for some time in an unrefrigerated place decomposes.
b. Apple juice which is left in an open bottle, ferments.
c. A loaf of bread rises and its volume expands when it is baked in an oven.
d. When a lake starts to freeze in winter, ice is formed on the surface.
e. When sugar is fermented under certain conditions, alcohol is produced.
Answer: d
Section 1.2
Difficulty Level: easy
25. Which one of the following is a chemical change?
a. When blood is mixed with 3% hydrogen peroxide solution, it changes color.
b. When water is boiled, it forms steam.
c. When a solid stick of butter is heated, it becomes a liquid.
d. When blue paint is mixed with yellow paint, a green colored paint is obtained.
e. When a bar of gold metal is pounded with a hammer, it flattens out.
Answer: a
Section 1.2
Difficulty Level: easy
26. Which of the following is not a chemical change?
a. A nail rusts when exposed to air and moisture.
b. Milk turns sour if left unrefrigerated.
c. Yeast produces carbon dioxide to help bread rise.
d. Copper is molded with heat to form pipes.
e. Mixing baking soda and vinegar causes fizzing and bubbling.
Answer: e
Section 1.2
Difficulty Level: easy
27. Each of the following properties of a sample of a pure substance can be used for identification except its
a. density.
b. freezing point temperature.
c. mass.
d. melting point temperature.
e. solubility in water.
Answer: c
Section 1.3
Difficulty Level: easy
28. A physical property is one that
a. can be observed without changing the chemical identity of a substance.
b. is based on one particular scientific law.
c. describes a chemical reaction that a substance undergoes.
d. cannot be seen with the naked eye.
e. is considered hypothetical in origin.
Answer: a
Section 1.3
Difficulty Level: medium
29. Which is an example of a physical property?
a. corrosiveness of sulfuric acid
b. toxicity of cyanide
c. flammability of gasoline
d. neutralization of stomach acid with an antacid
e. lead become a liquid when heated to 601 °C
Answer: e
Section 1.3
Difficulty Level: easy
30. Which is an example of a physical property?
a. dynamite explodes
b. meat rots if it is not refrigerated
c. honey tastes sweet
d. ice floats on top of liquid water
e. a silver platter tarnishes over time.
Answer: e
Section 1.3
Difficulty Level: medium
31. All of these statements describe properties of sodium. Which one describes a physical property of sodium?
a. Sodium’s surface turns black when first exposed to air.
b. Sodium is a solid at 25°C and changes to a liquid when heated to 98°C.
c. When exposed to water, sodium reacts violently and a gas is formed.
d. When placed in contact with chlorine, sodium forms a compound that melts at 801°C.
e. Sodium is never found as a pure metal in nature.
Answer: b
Section 1.3
Difficulty Level: medium
32. Water can also exist as a gas that is called
a. ice.
b. steam.
c. the melt.
d. molecules.
e. atomic water.
Answer: b
Section 1.3
Difficulty Level: medium
33. Which of the following describes a chemical property?
a. A property based solely on the scientific method.
b. A property which is based on a particular scientific law.
c. A property which describes a change a substance undergoes.
d. A property which cannot be seen.
e. A property which is considered hypothetical.
Answer: c
Section 1.3
Difficulty Level: medium
34. All of these statements describe properties of tin. Which one describes a chemical property of tin?
a. Tin can be hammered into a thin sheet.
b. The density of white tin is 7.365 g cm-3.
c. Tin melts at 231.9°C.
d. When a bar of tin is bent, it emits an audible “cry”.
e. Tin dissolves slowly in cold, dilute hydrochloric acid, but it dissolves readily in concentrated hydrochloric acid.
Answer: e
Section 1.3
Difficulty Level: medium
35. Which is an example of a chemical property?
a. combustibility
b. volatility
c. viscosity
d. malleability
e. ductility
Answer: a
Section 1.3
Difficulty Level: easy
36. Which is an example of an intensive property of matter?
a. color
b. volume
c. mass
d. weight
e. length
Answer: a
Section 1.3
Difficulty Level: medium
37. Which is an example of an intensive property of matter?
a. temperature
b. volume
c. length
d. weight
e. melting point
Answer: e
Section 1.3
Difficulty Level: medium
38. Which is an example of an extensive property of matter?
a. color
b. density
c. mass
d. melting point
e. flash point
Answer: c
Section 1.3
Difficulty Level: medium
39. Which is an example of an extensive property of matter?
a. surface area
b. boiling point
c. density