STARR Chemistry Review

NAME __________________________________________PERIOD_______

2013 Chemistry STAAR BENCHMARK review

1.  When preparing to light a gas burner, which of the following should you do first?

A    Determine which burner model you are working with.

B    Connect the burner to the gas supply.

C    Close the air vents.

D    Make sure that flammable chemicals are not being used.

2.  Which of the following phrases apply to scientific theories but NOT to hypotheses?

A    tentative and testable                          

B    well-established and highly reliable

C    based on observation and testing        

D    scientific and proven

3.  Science differs from other disciplines, such as history and the arts, because ONLY science relies on

A    facts.                                                      B    observations.

C    testing explanations.                             D    personal opinion.

4.  Based on observations that you make, you suggest that sugar dissolves faster in warm water than in cool water. This is a(an)

A    conclusion.                                             B   experiment.

C  hypothesis.                                                D.   analysis

5.  To demonstrate that you understand the limitations of science, identify which of the following is NOT a testable scientific hypothesis.

A    The volume of a helium-filled balloon increases as the balloon rises in the atmosphere.

B    Skim milk tastes better than whole milk.  

C    Steel is a more flexible metal than brass.

D    Listening to classical music increases test scores.

Pure water freezes at 0ºC. A student wants to test the effect of adding table salt to the water.

Use the table below to answer Questions 7–10.

Effect of Salt on Freezing Point of Water
Salt added	Freezing point
5 g	–4.8ºC
10 g	–9.7ºC
15 g	–15.1ºC

   6.  Interpret Tables What are the independent and dependent variables?

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   7.  Control Variables Why must the volume of water be the same for each test?

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8.  A theory is a well-established, highly-reliable, and testable explanation that unifies a range of related observations and hypotheses. A hypothesis is much narrower. It is a testable explanation for an observation. Identify whether each statement below is a hypothesis or a theory. For a hypothesis, write “H” on the line. For a theory, write “T.”

        __________         The rate at which a chemical reaction proceeds is related to the surface area of the reactants.

        __________         All matter consists of tiny particles that are in constant motion.

        __________         The universe began about 15 billion years ago.

        __________         New tennis balls bounce higher than old tennis balls.

__________         Caffeine raises blood pressure

9.  Select the appropriate piece of scientific glassware that you would use to measure the volume of a liquid.

A    test tube                                                B    graduated cylinder

C funnel                                                            D    ring stand

10.  An experiment requires exactly 10.5 g of sodium nitrate. Which piece of equipment would   you use to measure this quantity?

A    spring scale                                           B    electronic balance

C    graduated cylinder                                D    volumetric flask

11.  You need to accurately determine the acidity of a solution in which a chemical reaction is occurring. Which device would you use?

A    temperature probe                               B    pH paper

C    pH meter                                               D    voltmeter

12. Which of the following is the BEST description of a hypothesis?

A    a possible explanation for an observation

B    a guess

C    a well-established explanation that unifies many observations

D    a set of observations about one area of study

13. Why does a scientific theory take longer to develop than a hypothesis?

A    Theories must be well-established and highly reliable, which requires many investigations and experiments done by multiple independent researchers.

B    Unlike hypotheses, theories require time-consuming observations.

C    Theories must be well-established and highly reliable, which requires multiple hypotheses to be proven before a theory can be made.

D    Unlike hypotheses, theories need to be tested

14. Which of the following expressions is used to calculate the error of a measurement?

A    accepted value – experimental value   B    experimental value × accepted value

C    experimental value – accepted value   D    accepted value/experimental value

 15. A student measures the temperature of boiling water at standard temperature and       pressure. The measured value is 100.2°C. She repeats the measurement twice and measures 100.3°C both times. Her instructor expects the collected data to be precise within 0.2°C and accurate within 0.5°C. Which describes her result?

A    neither acceptably accurate nor acceptably precise

B    not acceptably accurate but acceptably precise

C    acceptably accurate but not acceptably precise

D    acceptably accurate and acceptably precise

16.  All of the following are extensive properties except:

        A.  volume

        B.  mass

        C.  density

        D.  amount of energy in a substance

17.  All of the following are intensive properties except:

       A.  melting point

B.  boiling point

       C.  density

       D.  mass

18.  Which of the following is a physical change?

       A.  iron rusting

       B.  ice melting

       C.  silver tarnishing

       D.  paper burning

19. Which of the following is a homogeneous mixture?

       A.  air

       B.  blood

       C.  gold

       D.  sand and pebbles

20.  Which of the following is a compound?

       A.  gold

       B.  oxygen

       C.  water

       D.  aluminum

21. Elements with similar chemical properties would be in the same

       A.  period

       B.  property line

       C.  group

       D.  horizontal row

22.  Malleable means

       A.  rolled into a ball

       B.  drawn into a fine wire

       C.  shiny

       D.  hammered into thin sheets

23.  If the accepted value of a measurement is 2.21 g/mL and the measured experimental value is 3.28 g/mL, what is the accuracy expressed as percent error?

A    32.6%

B    40.3%

C    48.4%

D    67.4%

24. Which describes how opinion and scientific evidence are related?

A    An opinion is an idea that may be formed from evidence. 

B    Evidence is an idea that may be confirmed by an opinion.

C    Scientific evidence and opinion are the same thing.           

D    Scientific evidence and opinion are not related.

25. Express a mass of 5.712 grams in milligrams

       A.  57.12

       B.  5.7 x 10²³

       C.  5712

       D.  571.2

26. Suppose the value seven thousand centimeters is reported to you.  How should the number be expressed if it is intended to contain four significant figures?

       A.  7000 cm

       B.  7000. Cm

       C.  7000.00 cm

       D.  7.0 cm

27. Given: (52.6 cm) (1.214 cm)
What is the product expressed to the correct number of significant figures?

1. 64 cm²
2. 63.9 cm²
3. 63.86 cm²
4. 63.8564 cm²

28. Which measurement contains three significant figures?

1. 0.08 cm
2. 0.080 cm
3. 800 cm
4. 8.08 cm

29. Compared to the charge and mass of a proton, an electron has...

1. the same charge and a smaller mass
2. the same charge and the same mass
3. an opposite charge and a smaller mass
4. an opposite charge and the same mass

30. Which symbols represent atoms that are isotopes?

1. C-14 and N-14
2. O-16 and O-18
3. I-131 and I-131
4. Rn-222 and Ra-222

31. An ion with 5 protons, 6 neutrons, and a charge of 3+ has an atomic number of

1. 5
2. 6
3. 8
4. 11

32. What is the mass number of an atom which contains 28 protons, 28 electrons, and 34 neutrons?

1. 28
2. 56
3. 62
4. 90

33. A student determined the heat of fusion of water to be 366.9 J/g. If the accepted value is

333.3J/g, what is the student's percent error?

1. 8.0%
2. 10.0%
3. 15%
4. 30.0%

34. What occurs as potassium nitrate is dissolved in a beaker of water, indicating that the process is endothermic?

1. The temperature of the solution decreases.
2. The temperature of the solution increases.
3. The solution changes color.
4. The solution gives off a gas.

35. A solid is dissolved in a beaker of water. Which observation suggests that the process is endothermic?

1. The solution gives off a gas.
2. The solution changes color.
3. The temperature of the solution decreases.
4. The temperature of the solution increases.

36. To determine the density of an irregularly shaped object, a student immersed the object in 21.2 milliliters of H₂O in a graduated cylinder, causing the level of the H₂O to rise to 27.8 milliliters. If the object had a mass of 22.4 grams, what was the density of the object.

1. 27.8 g / mL
2. 6.6 g / mL
3. 3.0 g / mL
4. 3.4 g/ mL

37. Which statement describes a chemical property?

1. Its crystals are a metallic gray.
2. It dissolves in alcohol.
3. It forms a violet-colored gas.
4. It reacts with hydrogen to form a gas

38. When a metal atom combines with a nonmetal atom, the nonmetal atom will

1. lose electrons and decrease in size
2. lose electrons and increase in size
3. gain electrons and decrease in size
4. gain electrons and increase in size

39. Which set of elements contains a metalloid?

1. K, Mn, As, Ar
2. Li, Mg, Ca, Kr
3. Ba, Ag, Sn, Xe
4. Fr, F, O, Rn

40. What is the approximate energy of a photon having a frequency of 4 x 10⁷ Hz?

A.3 x 10^-27 J

B.3 x 10^-26 J

C.2 x 10^-41 J

D.3 x 10⁴² J

41. If an atom emitted a narrow band of orange light at a speed of 3.0 x 10⁸ m/s with a

wavelength of 6.2 x 10^–7 m, what would be the frequency of that light?

       A.1.9 x 10² Hz

       B.5.4 x 10^–3 Hz

       C.4.8 x 10¹⁴ Hz

       D.2.1 x 10^–15 Hz

42. To demonstrate that you understand the conclusions used in the development of modern atomic theory, identify the statement that is consistent with Rutherford’s nuclear atom.

A    All atoms have a positive charge.

B    Atoms are mostly empty space.

C    The nucleus of an atom contains protons and electrons.

D    Mass is spread uniformly throughout an atom.

43. Show that you understand the conclusions used in the development of modern atomic theory by completing the following statement: Bohr’s contribution to the development of atomic structure

A    was referred to as the “plum-pudding model.”

B    was the discovery that electrons surround a dense nucleus.

C    was the proposal that electrons travel in specific circular paths around the nucleus.

D    was the quantum mechanical model.  

44. To demonstrate that you understand the conclusions used in the development of modern atomic theory, identify the statement that is NOT part of Dalton’s postulates.

A    All elements are composed of atoms.

B    Atoms of the same element are alike.

C    Atoms are always in motion.

D    Atoms that combine do so in simple whole-number ratios.

45. To demonstrate that you understand the conclusions used in the development of modern atomic theory, identify how Bohr’s nuclear atom differs from Rutherford’s nuclear atom.

A    Bohr’s model proposed that electrons occupy orbits of different shapes.

B    Rutherford’s model explained the physical and chemical properties of elements, whereas Bohr’s model only explained the physical properties.

C    Bohr’s model states that electrons occupy orbits with fixed energy levels.

D    In Bohr’s model, electrons occupy space within a “cloud” surrounding the nucleus.

46. An atom of which of the following elements has the greatest ability to attract electrons?

1. silicon
2. sulfur
3. nitrogen
4. chlorine

47. At STP, which substance is the best conductor of electricity?

1. nitrogen
2. neon
3. sulfur
4. silver

48. Which substance cannot be decomposed into simpler substances?

1. ammonia
2. aluminum
3. methane
4. methanol

49. Which three groups of the Periodic Table contain the most elements classified as metalloids (semimetals)?

1. 1, 2, and 13
2. 2, 13, and 14
3. 14, 15, and 16
4. 16, 17, and 18

50. A strontium atom differs from a strontium ion in that the atom has a greater

1. number of electrons
2. number of protons
3. atomic number
4. mass number

51. What is the total number of atoms represented in the formula CuSO₄ ^. 5H₂O?

1. 8
2. 13
3. 21
4. 27

52. What is the molar mass of K₂CO₃?

1. 138 g
2. 106 g
3. 99 g
4. 67 g

53. What is the percent by mass of oxygen in magnesium oxide, MgO?

1. 20%
2. 40%
3. 50%
4. 60%

54. According to Hund’s rule, when electrons occupy orbitals of equal energy, one electron enters each orbital until

A    all the orbitals contain one electron, with spins parallel.

B    all the orbitals contain one electron, with opposite spins.

C    there are two electrons in each orbital.

D    electron velocities become constant.

55. Three isotopes of oxygen occur in nature: oxygen-16, oxygen-17, and oxygen-18. If the atomic mass of oxygen is 15.9994 amu, which of the three isotopes, if any, is the most abundant?

A    oxygen-16                                              B    oxygen-17

C    oxygen-18                                              D    All are equally abundant.

56. How many valence electrons does an atom of any element in Group 6A have?

A    2                                                             B    4

C    6                                                             D    8

57. What is the mass in grams of 3.50 mol of the element Copper?

       A.  222 g Cu

       B.  2.2 X 10²² g Cu

       C.  125 g Cu

       D.  7.0 g Cu

58. What is the electron configuration of the calcium ion?

A.1s²2s²2p⁶3s²3p⁵4s¹

B.1s²2s²2p⁶3s²3s²

C.1s²2s²2p⁶3s²3p⁶

D.1s²2s²2p⁶3s²3p⁴4s²

59. Which of the following elements forms an ion with a 1– charge?

A. fluorine

B. sodium

C. potassium

D. hydrogen

60. A chemist produced 11.9 g of aluminum.  How many moles of Al were produced?

       A. 26.98 mol Al

       B. 0.441 mol Al

       C. 44.1 mol Al

       D. 6.02 X 10²³ mol Al

61. What is the mass in grams of 1.20 x 10⁸ atoms of Cu?

       A. 1.27 x 10¹⁴ g Cu

       B. 1.27 g Cu

       C. 1.27 x 10^-14 g Cu

       D. 127 g Cu

62. What is the total number of moles of hydrogen gas contained in 9.03 x 10²³

1. 1.5 moles
2. 2.00 moles
3. 6.02 moles
4. 9.03 moles

63. What is the empirical formula of the compound whose molecular formula is P₄O₁₀?

1. PO
2. PO₂
3. P₂O₅
4. P₈O₂

64.  A compound is 86% carbon and 14% hydrogen by mass. What is the empirical formula for this compound?

1. CH
2. CH₂
3. CH₃
4. CH₄

65. At STP, 32.0 liters of O₂ contain the same number of molecules as

1. 22.4 L Ar
2. 28.0 L of N₂
3. 32. 0 L of H₂
4. 44.8 L of He

66. Given the reaction CH₄ + 20₂ --> C0₂ + 2H₂0,
What amount of oxygen is needed to completely react with 1 mole of CH₄?

1. 2 moles
2. 2 atoms
3. 2 grams
4. 2 molecules

67. Write the chemical formula for each of the following common
polyatomic ions:

A    phosphate ion                            ______________________________________________

B    nitrite ion                                   _____________________________________________

C    ammonium ion                          ______________________________________________

D    carbonate ion                            ______________________________________________

68. Write the chemical formulas for the following ionic compounds containing main group or transition metals:

A    lithium fluoride                         ______________________________________________

B    aluminum chloride                    ______________________________________________

C    iron(III) oxide                             ______________________________________________

D    sodium nitride                           ______________________________________________

69. Write the chemical formulas for the following covalent compounds:

A    dinitrogen tetroxide                  ______________________________________________

B    xenon tetrafluoride                   ______________________________________________

C    disulfur decafluoride                 ______________________________________________

D    iodine heptafluoride                  ______________________________________________

70. Covalent bonds usually form between

A    two nonmetals.                                      B    a metal and a nonmetal.

C    two metals.                                            D    two metalloids

71. Which of the following molecular formulas are also empirical formulas?

A    ribose (C₅H₁₀O₅)                                     B    ethyl butyrate (C₆H₁₂O₂)

C    chlorophyll (C₅₅H₇₂MgN₄O₅)                  D    DEET (C₁₂H₁₇ON)

72. Magnesium nitride is formed in the reaction of magnesium metal with nitrogen gas.

3Mg(s) + N₂(g) ® Mg₃N₂(s)

        The reaction of 4.0 mol of nitrogen with 6.0 mol of magnesium produces

        A  2.0 mol of Mg₃N₂ and no excess N₂.

        B  2.0 mol of Mg₃N₂ and 2.0 mol of excess N₂.

        C  4.0 mol of Mg₃N₂ and 1.0 mol of excess Mg.

        D  6.0 mol of Mg₃N₂ and 3.0 mol of excess N₂.

73. The equation for the complete combustion of methane is

CH₄(g) + 2O₂(g) ® CO₂(g) + 2H₂O(l)

        What is the first conversion factor needed to calculate the number of grams of CO₂ produced by the reaction of 29.5 g of CH₄ with O₂?

A                                                 B   

C                                                  D   

74. According to kinetic molecular theory, gases consist of particles that

A    occupy considerable volume.

B    are relatively close together.

C    exert attractive and repulsive forces on other particles.

D    have motion that is constant, random, and rapid.

75. Which of these statements are not true, according to kinetic molecular theory?

A    There is no attraction between particles of a gas.

B    Only particles of matter in the gaseous state are in constant motion.

C    The particles of a gas collide with each other and with other objects.

D    All collisions between particles of a gas are perfectly elastic.

76. Which of these statements are characteristic of matter in the gaseous state?

A    Gases fill their containers completely.

B    Gases exert pressure.

C    Gases have mass.

D    The pressure of a gas is independent of the temperature.

E    Gases are compressible.

77. Which sequence has the states of methanol (CH₄O) correctly ordered in terms of increasing average kinetic energy?

A    CH₄O(s), CH₄O(g), CH₄O(l)

B    CH₄O(g), CH₄O(l), CH₄O(s)

C    CH₄O(l), CH₄O(g), CH₄O(s)

D    CH₄O(s), CH₄O(l), CH₄O(g)

78. What Kelvin temperature is equal to 25°C?

1. 248 K
2. 298 K
3. 100 K
4. 200 K

79. As the pressure of a gas at 2 atm is changed to 1 atm at constant temperature, the volume of the gas

1. decreases
2. increases
3. remains the same
4. is directly proportional

80. Why does increasing the volume of a given amount of gas at a constant temperature cause the pressure to decrease?

A    The molecules are striking a larger area with the same force.

B    There are fewer molecules.

C    The molecules are moving more slowly.

D    There are more molecules.

81. A breathing mixture used by deep-sea divers contains helium, oxygen, and carbon dioxide. Calculate the total pressure of the gas mixture, as described by Dalton’s law of partial pressures, if the partial pressures of helium, oxygen, and carbon dioxide are 84.0 kPa, 17.2 kPa, and 0.10 kPa, respectively.

A    66.7 kPa                                                 B    66.9 kPa

C    101.1 kPa                                               D    101.3 kPa

82. Calculate the volume in liters of 5.00 moles of gas that has a pressure of 150. kPa at a temperature of 295. K .

83. You have 5.03 x 10²¹ moles of CaCl₂ .  Calculate how many ions of Cl^- you have.