Chem Test
Chapter 2 – Matter, Properties, and Changes – Flashcards
1. Describe the difference between an extensive property and an intensive property and give an example of each.
An intensive property depends on the type of matter and does not depend on the amount (e.g., density, melting point). An extensive property depends on the amount of matter in the sample (e.g., mass, volume).
2. List three physical properties of copper.
Reddish-yellow color, melting point 1084°C, boiling point 2562°C.
3. Name two physical properties that could be used to distinguish between water and ethanol.
Melting point and boiling point.
4. Name one physical property that could not be used to distinguish chlorine from oxygen. Why?
State of matter, because both are gases at room temperature.
5. What is the state of matter for gold?
Solid.
6. What is the state of matter for gasoline?
Liquid.
7. What is the state of matter for neon?
Gas.
8. What is the state of matter for olive oil?
Liquid.
9. What is the state of matter for oxygen?
Gas.
10. What is the state of matter for mercury?
Liquid.
11. Fingernail polish remover (mostly acetone) is a liquid at room temperature. Would you describe acetone in the gaseous state as a vapor or as a gas?
Acetone is a vapor because it normally exists as a liquid at room temperature; it becomes gas only when heated.
12. Compare the arrangements of individual particles in solids, liquids, and gases.
Solids: tightly packed, vibrate in place, not easily compressed
Liquids: close together, move past each other, not easily compressed
Gases: far apart, move freely, easily compressed
13. Use Table 2.1 to identify four substances that undergo a physical change if the temperature is reduced from 50°C to -50°C. What is the physical change for each?
Chlorine: condenses
Mercury: freezes
Bromine: freezes
Water: freezes
14. Explain why sharpening a pencil is a different type of physical change than freezing water into ice cubes.
Sharpening a pencil is irreversible; freezing water is reversible.
15. What is the difference between homogeneous mixtures and heterogeneous mixtures?
Homogeneous: uniform composition.
Heterogeneous: non-uniform composition with two or more phases.
16. How many phases does a solution have? Explain your answer.
One phase, because solutions are homogeneous mixtures.
17. Classify chocolate chip cookies as homogeneous or heterogeneous.
Heterogeneous.
18. Classify green ink as homogeneous or heterogeneous.
Homogeneous.
19. Classify cake batter as homogeneous or heterogeneous.
Heterogeneous.
20. Classify cooking oil as homogeneous or heterogeneous.
Homogeneous.
21. What is the goal of a distillation?
To separate the components of a solution.
22. How is distillation accomplished?
The liquid mixture is heated to produce a vapor, which is then condensed into a liquid.
23. How could you distinguish an element from a compound?
Compounds can be separated into simpler substances by chemical means; elements cannot.
24. Use the symbols W and Hg to explain the system of symbols for elements.
W: single capital letter; Hg: first letter capital, second letter lowercase.
25. What does the formula H₂O tell you about the composition of water?
Water contains 2 hydrogen atoms and 1 oxygen atom.
26. Use the word equation to explain how a chemical change differs from a physical change.
Iron + sulfur → (heat) → iron sulfide. Chemical changes produce new substances; physical changes do not.
27. Classify a copper wire being bent. Physical or chemical change?
Physical.
28. Classify charcoal burning on a grill. Physical or chemical change? Provide a clue.
Chemical; clue: color change.
29. Classify bread dough rising when yeast is added. Physical or chemical change? Provide a clue.
Chemical; clue: gas is produced.
30. Classify sugar dissolving in water. Physical or chemical change?
Physical.
31. Which type of property cannot be observed without changing the composition of a substance?
Chemical property.
32. When ammonium nitrate explodes, the products are nitrogen, oxygen, and water. If 40 g of ammonium nitrate explode and 14 g of nitrogen and 8 g of oxygen form, how many grams of water form?
18 g of water.
33. If the composition of a material is fixed, the material is called…
A substance.
34. If the composition of a material may vary, the material is called…
A mixture.
35. What is a chemical formula?
Represents compounds; consists of chemical symbols and subscripts indicating the relative proportion of elements (e.g., H₂O).
36. What is a chemical property?
The ability of a substance to undergo a specific chemical change; observed only during a reaction (e.g., iron rusting).
37. Define distillation.
Process in which a liquid mixture is heated to produce vapor, which is condensed back into liquid.
38. Define filtration.
Method to separate a solid from a liquid.
39. Define mixtures.
Physical blends of two or more components; can be homogeneous or heterogeneous.
40. Give an example of separating a mixture using filtration.
Separating sand from saltwater.
41. Give an example of a reversible physical change.
Freezing water into ice.
42. Give an example of an irreversible physical change.
Sharpening a pencil.
43. Give an example of separating a mixture using solubility.
Dissolve salt in water, filter out sand, evaporate water to recover salt.
44. Law of conservation of mass: how does it apply to chemical reactions?
Mass of reactants equals mass of products.
45. List clues that a chemical change has occurred.
Transfer of energy (heat/light), color change, gas production, formation of a precipitate.
46. Compare properties of solids, liquids, and gases.
Solids: definite shape & volume
Liquids: definite volume, indefinite shape
Gases: indefinite volume & shape
47. Explain how filtration differs from distillation.
Filtration separates solid from liquid without changing the liquid; distillation separates based on boiling points.
48. What is an example of a chemical property in iron?
Ability to rust when combined with oxygen.
49. Lesson 2.1: Explain intensive properties.
Intensive properties do not depend on amount; all samples of a pure substance share them (e.g., density, melting point).
50. Lesson 2.1: Identify states of matter.
Solid, liquid, gas, plasma.
51. Lesson 2.1: Classify physical changes.
Reversible: can be undone (e.g., melting, freezing).
Irreversible: cannot be easily undone (e.g., cutting, breaking).
52. Lesson 2.1: Classify properties.
Intensive: independent of amount (e.g., hardness, melting point).
Extensive: dependent on amount (e.g., mass, volume).
53. Lesson 2.1: Distinguish sodium chloride.
Melting point 801°C or boiling point is the most distinguishing property.
54. Lesson 2.1: Compare liquids, gases, and solids.
Liquids & gases: fluids, take container shape.
Liquids & solids: solids have definite shape/volume; liquids definite volume, indefinite shape.
55. Lesson 2.1: Freezing of mercury.
Reversible physical change; frozen mercury can melt back without changing chemical identity.
56. Lesson 2.1: Extensive vs. intensive properties.
Extensive (mass, volume) depend on amount; intensive (density, melting point) depend on type of substance.
57. Lesson 2.1: Applications (big idea).
Used in engineering (material selection), medicine (drug composition), geology (mineral identification).
58. Lesson 2.2: Separating iron and salt.
Magnetism separates iron; solubility in water separates salt.
59. Lesson 2.2: Separating gases in air.
Fractional distillation based on differences in boiling points.
60. Lesson 2.2: Phases and mixtures.
Phase: part of sample with uniform properties.
Homogeneous: 1 phase.
Heterogeneous: 2+ phases.
61. Lesson 2.2: Classify mixtures.
Food coloring: homogeneous
Ice cubes in water: heterogeneous
Mouthwash: homogeneous
Mashed, unpeeled potatoes: heterogeneous
62. Lesson 2.2: Substance vs. solution.
Similar: both homogeneous.
Different: substance has fixed composition; solution variable composition.
63. Lesson 2.2: Filtration vs. distillation.
Filtration: separates undissolved solid from liquid.
Distillation: separates dissolved solid or two liquids with different boiling points.
64. Lesson 2.2: Separate sand and salt.
Dissolve salt in water, filter to collect sand, evaporate water to recover salt.
65. Lesson 2.3: Substance vs. mixture.
Substance: fixed composition, unique properties.
Mixture: variable composition, physically separable.
66. Lesson 2.3: Symbols and formulas.
Symbols (O, Fe) represent elements.
Formulas (H₂O) show elements and number of atoms in a compound.
67. Lesson 2.3: Usefulness of periodic table.
Organizes elements, groups similar chemical properties, predicts behavior.
68. Lesson 2.3: Breaking down compounds.
Use heating (thermal decomposition) or electrolysis.
69. Lesson 2.3: Classify matter.
Table sugar: compound
Tap water: mixture
Cough syrup: mixture
Nitrogen: element
70. Lesson 2.3: Chemical symbols.
Lead: Pb
Oxygen: O
Silver: Ag
Sodium: Na
Hydrogen: H
Aluminum: Al
71. Lesson 2.3: Element names.
C: Carbon
Ca: Calcium
K: Potassium
Au: Gold
Fe: Iron
Cu: Copper
72. Lesson 2.3: Acetaminophen (C₈H₉NO₂).
Elements: C, H, N, O. Hydrogen in greatest proportion (9 atoms).
73. Lesson 2.3: Elements similar to calcium.
Beryllium (Be) and magnesium (Mg) – same group 2A.
74. Lesson 2.4: Chemical change and composition.
Chemical changes alter chemical composition; atoms rearranged to form new substances.
75. Lesson 2.4: Clues for chemical change.
Energy transfer, color change, gas production, precipitate formation.
76. Lesson 2.4: Law of conservation of mass.
Mass of reactants equals mass of products.
77. Lesson 2.4: Physical vs. chemical changes.
Physical: form changes, composition same.
Chemical: new substances formed.
78. Lesson 2.4: Classify changes.
Waxing skis: physical
Salt dissolves in water: physical
Milk turns sour: chemical
Metal rusts: chemical
79. Lesson 2.4: Mass calculation example.
4.8 g + 38.4 g = 43.2 g of water.