Exam 1 Practice

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Scientific Method, Properties, Classification of Matter

  1. Classify each statement as being either qualitative or quantitative.

    1. This recitation worksheet took a good amount of time to complete
    2. This recitation worksheet took 50 minutes to complete
    3. The University of Georgia is a very large school

    Solution


  2. Which statement best explains the difference between a law and a theory?

    1. A law is truth whereas a theory is mere speculation.
    2. A law summarizes a series of related observations, while a theory gives the underlying reasons for them.
    3. A theory describes what nature does; a law explains why nature does it.

    Solution


  3. A scientific law…

    1. is a statement that summarizes past observations and makes predictions.
    2. is subject to change via legal action.
    3. contains an explanation of observations.
    4. must have a mathematical formula.
    5. cannot be modified.

    Solution


  4. All statements about scientific theories are true except

    1. they explain why nature behaves the way it does.
    2. they must have the ability to make predictions on future behavior.
    3. they should use observations to test the theory.
    4. they are derived from hypothesis.
    5. they are speculation.

    Solution


  5. Which of these represents a hypothesis?

    1. Sodium reacts with water to form sodium hydroxide and hydrogen gas.
    2. Nitrogen gas is a fairly inert substance.
    3. Nickel has a silvery sheen.
    4. When a substance combusts, it combines with air.
    5. When wood burns, heat is given off.

    Solution


  6. Which of the following is a homogeneous mixture?

    1. wine
    2. mud
    3. salad
    4. salsa

    Solution


  7. Which of the following is a heterogeneous mixture?

    1. sports drink
    2. chlorine gas
    3. black coffee
    4. bowl of cereal
    5. carbon (graphite)

    Solution


  8. Which of the following is not an example of a homogeneous mixture?

    1. air
    2. rain
    3. steel
    4. blood
    5. coffee

    Solution


  9. Molecules can be described as

    1. mixtures of two or more pure substances
    2. mixtures of two or more elements that has a specific ratio between components
    3. two or more atoms chemically joined together
    4. heterogeneous mixtures
    5. homogeneous mixtures

    Solution


  10. Which of these separations cannot be achieved using a physical process and, therefore, requires a chemical process?

    1. salt from sea water
    2. water from honey
    3. hydrogen from water
    4. ice from water
    5. fish from water

    Solution


  11. All of the following will lead to a heterogeneous mixture except (select all that apply)

    1. sugar and coffee
    2. mud and water
    3. salt and water
    4. tea and no-pulp lemonade
    5. vinegar and water

    Solution


  12. How are gases different from solids and liquids?

    1. Gases can only be made up of atoms
    2. Particles in a gas attract each other more strongly than in solids and liquids
    3. Gases are compressible
    4. Only gases can take the shape of their container
    5. Gases are colorless

    Solution


  13. Identify the incorrect statement.

    1. Helium in a balloon is an element
    2. Paint is a mixture
    3. Tap water is a compound
    4. Mercury in a barometer is an element

    Solution


  14. Which answer includes all the following that are chemical changes and not physical changes?
     I. freezing of water
     II. rusting of iron
     III. dropping a piece of iron into hydrochloric acid where H2(g) is produced
     IV. burning of a piece of wood
     V. emission of light by a kerosene oil lamp

    1. III and IV
    2. II and V
    3. I, II, III, IV, and V
    4. II, III, and V
    5. II, III, IV, and V

    Solution


  15. Which answer includes all of the following properties of sulfur that are physical properties and not other properties?
     I. It reacts with hydrogen when heated
     II. It is a yellow solid at room temperature
     III. It is soluble in carbon disulfide
     IV. It has a density of 2.97 g cm–3
     V. It melts at 112 °C

    1. II, III, IV, and V
    2. II, IV, and V
    3. I
    4. II, III, and IV
    5. III, IV, and V

    Solution


  16. Which of the following is a chemical change?

    1. forging of metal
    2. boiling water
    3. shattering glass
    4. rust forming on a bike
    5. melting ice

    Solution


  17. Which of the following would you expect to have the highest density?

    1. oxygen
    2. lead
    3. water
    4. helium

    Solution


Measurements, Derived Units, Significant Figures

  1. A student is using a graduated cylinder to measure the volume of a liquid. What reading should be recorded?

    Solution


  2. A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 1.11 g mL–1, 1.81 g mL–1, 1.95 g mL–1, 1.75 g mL–1. The actual value for the density of the sugar solution is 1.75 g mL–1. Determine if the following statements are true or false.

    1. Her results are precise.
    2. Her results are accurate.

    Solution


  3. A student goes to the lab and is tasked with measuring the mass of a block of nickel metal that has a known mass of 15.00 g. The student takes three different measurements in which they collect the following masses: 13.29 g, 13.28 g, and 13.29 g. What statement best describes their results?

    1. Their measurements are both precise and accurate
    2. Their measurements are precise, but not accurate
    3. Their measurements are accurate, but not precise
    4. Their measurements are neither precise or accurate

    Solution


  4. Write the following numbers in normalized scientific notation to three significant figures.

    1. 0.000 467 01
    2. 8 973.002
    3. 0.027 902 0
    4. 32.451 3
    5. 0.000 090 999

    Solution


  5. How many significant figures are in each number?

    1. 554 km
    2. 7 pennies
    3. 1.01 × 105 m
    4. 0.00099 s
    5. 1.4500 km
    6. 21 000 m

    Solution


  6. Determine the number of significant figures for each of the following values.

    1. 4 700
    2. 0.470 0
    3. 4 700 pencils
    4. 00.470 0
    5. 4 700.0 g
    6. 4 700.010 0

    Solution


  7. How many significant figures are in the answer to the following calculation?

    \[\left ( 29.0025 + 0.2 \right ) \left (6.134 - 6.101 \right ) / 5.196\times 10^{-2}\]

    Solution


  8. What answer should be reported, with the correct number of significant figures, for the following calculation? Report your answer in scientific notation.

    \[\left ( 433.621 - 333.9 \right ) \times 11.900\]

    Solution


  9. Perform the following conversions below. Report your answers in normalized scientific notation to the appropriate number of significant figures.

    1. 145.21 kg to mg
    2. 0.490 nm to m
    3. 42.1 cm3 to L
    4. 1.73 × 105 m3 to cm3

    Solution


  10. Which of the following options is at the highest temperature?

    1. 71.4 °F
    2. 22.1 °C
    3. 294.65 K

    Solution


  11. The average daytime temperatures on Earth and Jupiter are 72 °F and 313 K, respectively. Which planet is hotter, on average, and by how much (in °C)?

    Solution


  12. What is the length (in mm) of 3.20 cm?

    Solution


  13. If the walls in a room are 955 ft2 in area, and a gallon of paint covers 15 yd2, how many gallons of paint are needed for the room? (3 ft = 1 yd)

    Solution


  14. A piece of metal ore has a mass of 9.25 g. When a student places it into a graduated cylinder containing water, the liquid level rises from 21.25 mL to 26.47 mL. What is the density (in g mL–1) of the ore?

    Solution


  15. A sample containing 33.42 g of metal pellets is poured into a graduated cylinder that initially contains 12.7 mL of water. The final water level in the cylinder is 21.6 mL. What is the density (in g mL–1) of the metal?

    Solution


  16. Nitric acid is a very important industrial chemical and 1.612 × 1010 lb were produced in 1992. If the density of nitric acid is 12.53 lb gal–1, what is the volume (in L)? 1 gal = 3.7854 L

    Solution


  17. A rectangular block has the following dimensions: 2.9 cm × 3.5 cm × 10.0 cm. The mass of the block is 615.0 g. What is the volume (in cm3) and density (in kg m–3) of the block?

    Solution


  18. At room temperature, elemental bromine (Br2) is a liquid with a density of 3.12 g cm–3. What is the mass (in g) of 125 mL of bromine and what volume (in mL) does 85.0 g of bromine occupy?

    Solution


  19. The Hindenburg contained 7.062 × 106 ft3 of a gas. If the gas was helium ( d(He) = 1.78 × 10–4 g mL–1 ), how much lighter (in kg) would it be than if the gas was air (d(air) = 1.293 × 10–3 g mL–1)? (1 ft = 0.3048 m)

    Solution


Atoms, Atomic Theory, Periodic Table

  1. An unused flashbulb contains magnesium and oxygen. After use, the contents are changed to magnesium oxide but the total mass does not change. This observation can best be explained by the…

    1. Law of Constant Composition
    2. Law of Multiple Proportions
    3. Avogadro’s Law
    4. Law of Conservation of Mass

    Solution


  2. Which of the statements about two isotopes is false?

    1. They will have the same charge on the nucleus.
    2. They will have different numbers of neutrons.
    3. They will have essentially the same chemical reactivity.
    4. They will have the same atomic numbers.
    5. They will have the same atomic weights.

    Solution


  3. What is the mass number for 25Mg?

    Solution


  4. Which of the following represents isotopes?
     I. \(^{46}_{21}X\)
     II. \(^{46}_{22}X\)
     III. \(^{46}_{21}X\)
     IV. \(^{46}_{23}X\)

    1. I and II
    2. I and III
    3. I and IV
    4. III and IV

    Solution


  5. Complete the table.


    Solution


  6. Write the group number for each of the following elements.

    1. Ba
    2. Sb
    3. Zr
    4. Tl
    5. Rn

    Solution


  7. Write the period number for each of the following elements.

    1. Hf
    2. Am
    3. Ga
    4. Si
    5. He

    Solution


  8. Which of the following elements is a metal?

    1. Ge
    2. Sb
    3. H
    4. Sn
    5. Cl

    Solution


  9. Which of the following elements is a nonmetal?

    1. Ca
    2. Si
    3. Mo
    4. Cs
    5. Se

    Solution


  10. What quantity did J. J. Thompson determine using a cathode ray tube?

    1. the mass of an electron
    2. the charge-to-mass ratio of an electron
    3. the density of a proton
    4. the charge of a neutron
    5. the charge-to-mass ratio of a proton

    Solution


  11. Which of the following is found in the nucleus?

    1. cations
    2. neutrons
    3. electrons
    4. anions
    5. none of these

    Solution


  12. Which of these is not found in an atom?

    1. electron
    2. neutron
    3. photon
    4. proton
    5. all of them are

    Solution


  13. True or False: an atom consists mostly of empty space.

    1. true
    2. false, an atom consists primarly of electrons
    3. false, an atom consists primarily of the nucleus
    4. false, an atom consists primarly of neutrons
    5. false, an atom consists primarly of protons

    Solution


  14. Which of the following contribute to the mass of an atom? (select all that apply)

    1. protons
    2. neutrons
    3. electrons
    4. electrons
    5. the nucleus
    6. atomic charge

    Solution


  15. An element consists of four naturally occurring isotopes. The percent abundance and isotope masses are given as:

    1. 1.40 %; 203.973 u
    2. 24.10 %; 205.9754 u
    3. 22.10 %; 206.9759 u
    4. 52.40 %; 207.9766 u

    Find the standard atomic weight (in u) of the element

    Solution


  16. The element rhenium (Re) has a standard atomic weight of 186.207 and exists as two naturally occurring isotopes. Given the following percent abundance and isotope mass

    1. 185Re
    2. 187Re: 62.60 %; 186.956

    find the relative atomic weight of rhenium-185.

    Solution


Ions, Ionic Compounds, Molecules, and Nomenclature

  1. What is the correct charge of a sulfur atom with 16 protons, 16 neutrons, and 18 electrons?

    Solution


  2. What charge will most likely be formed by lithium?

    Solution


  3. Is iodine more likely to gain or lose an electron?

    Solution


  4. What is the atomic mass (in amu) of a magnesium ion containing 12 protons, 13 neutrons, and 10 electrons?

    Solution


  5. Fill out the missing information regarding a binary ionic compound.

    1. Name: sodium chloride
    2. Cation:
    3. Anion:
    4. Formula:

    Solution


  6. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation: Mg2+
    3. Anion: O2–
    4. Formula:

    Solution


  7. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation:
    3. Anion:
    4. Formula: Al2S3

    Solution


  8. Fill out the missing information regarding a binary ionic compound.

    1. Name: iron(III) oxide
    2. Cation:
    3. Anion:
    4. Formula:

    Solution


  9. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation: Sn2+
    3. Anion: Cl
    4. Formula:

    Solution


  10. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation:
    3. Anion:
    4. Formula: PbF4

    Solution


  11. Fill out the missing information regarding a binary ionic compound.

    1. Name: sodium hydroxide
    2. Cation:
    3. Anion:
    4. Formula:

    Solution


  12. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation: Mg2+
    3. Anion: CO32–
    4. Formula:

    Solution


  13. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation:
    3. Anion:
    4. Formula: Na2SO3

    Solution


  14. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation: Fe2+
    3. Anion: OH
    4. Formula:

    Solution


  15. Fill out the missing information regarding a binary ionic compound.

    1. Name:
    2. Cation:
    3. Anion:
    4. Formula: TiPO3

    Solution


  16. Provide the names for the following compounds

    1. N2O
    2. P2O5
    3. SF2
    4. S2O
    5. P2I4

    Solution


  17. What is the proper chemical formula for lithium hypoiodite?

    1. LiIO
    2. LiO2
    3. LiIO3
    4. LiIO3
    5. LiIO4

    Solution


  18. Write the chemical formula for a compound formed between aluminum and sulfur.

    Solution


  19. In which set do all elements tend to form cations in binary ionic compounds?

    1. Na, Al, S
    2. Ca, Mn, Sn
    3. P, As, Sb
    4. S, Cl, Br

    Solution


  20. Which of the following contains both ionic and covalent bonds?

    1. CaBr2
    2. COS
    3. BaSO4
    4. SF6
    5. none of these

    Solution


  21. What is the name of the C3H8?

    1. hexane
    2. propane
    3. decane
    4. butane
    5. ethane

    Solution


  22. What is the name of this compound?

    Solution


  23. What is the chemical formula for magnesium carbide?

    Solution


  24. What is the name of PH3?

    Solution


  25. Write the empirical formulas for the following compounds

    1. iron(II) sulfide
    2. iron(III) sulfide
    3. iron(II) sulfate
    4. iron(III) sulfate
    5. iron (II) sulfite

    Solution


  26. Provide the name for each of the following and identify it as a molecular or ionic compound


    Solution


  27. Provide the name for each of the following and identify it as a molecular or ionic compound


    Solution


  28. Provide the name for each of the following and identify it as an alkane, alcohol, or carboxylic acid.


    Solution


  29. Provide the chemical formulas and identify each as molecular or ionic compound. Include phase labels where necessary.


    Solution


  30. Provide the chemical formulas and identify each as molecular or ionic compound. Include phase labels where necessary.


    Solution





Questions are written by UGA Chemistry unless otherwise indicated and translated with minor tweaks into an online format by Eric Van Dornshuld.