Exam Review – Chemistry Topics
STRATEGY: Start by reading through your notes to refresh your memory on these topics. Then, use this review sheet as a starting point to identify the areas on which you need to spend more study time. For those areas, go back to homework assignments, quizzes, and reviews to practice more problems. Many of these are available on the Web site – check the lecture notes and old assignments.
FORMAT:
Questions will include multiple-choice and matching. You will need a calculator and a pencil for the Scantron form.
A periodic table and conversion chart will be provided.
The Nature of Science
Identify each of the following examples as PURE or APPLIED sciences.- Development of the computer chip.
- Study of sound waves.
- SONAR mapping of the ocean floor.
- Investigating the properties of silicon.
After reading cooking instructions that said to add salt to water before boiling it, Jose guessed that adding salt must make the water boil at a higher temperature. He decided to test his idea by performing the following experiment.
Jose measured out 1 quart of distilled water and added to it 2 tablespoons of salt. He then brought the water to a boil and measured its maximum temperature. Jose ran two more trials using 2 tablespoons of salt. He then ran 3 trials each with 4 tablespoons of salt and 6 tablespoon of salt. For each trial in his experiment, Jose used 1 quart of distilled water and the same pot and stove. The average temperature for 2 tablespoons of salt was 102.7C. The average temperature for 4 tablespoons of salt was 105.4C. The average temperature for 6 tablespoons of salt was 107.1C. Since Jose knew that the boiling point of water is 100C, he concluded that adding salt to water does cause it to boil at a higher temperature.
- What was Joe’s hypothesis?
- What was Joe’s conclusion?
- What component of experimental design is missing?
- List the dependent and independent variables.
Measurement
- A sample of cork has a mass of 54 g and a volume of 225 cm3. What is its density?
- Osmium is the densest element with a density of 22.57 g/cm3. Find the mass of a sample of osmium that occupies a volume of 6.5 cm3.
- A typical ant is 3 ___ (unit?) long.
- A typical man weighs 85 ___ (unit?).
- A soda can contains 355 ___ (unit?) of soda.
- 230 g = kg
- 4.35 m = cm
- 89.6 mm = m
- How many centimeters long is the proverbial “10-foot pole?”
- How many milliliters are in a 2.0 quart jug of milk?
- Calculate density from the slope of a graph (see test).
Matter
Classify as solid, liquid, gas, or plasma (20-23).- low KE, classified as crystalline or amorphous
- very high KE, positively & negatively charged particles
- high KE, uncharged particles can spread out
- fairly low KE, particles can move around each other
- A balloon inflated in a cooled store pops in a hot car.
- An air bubble released 30 feet underwater, expands in size as it rises to the surface.
- As temperature increases, the liquid in a thermometer rises up the tube.
- A transition from gas to liquid.
- A transition from liquid to gas at the boiling point.
- A transition from liquid to solid.
- A transition from solid to gas.
- A transition from liquid to gas below the boiling point.
- A transition from solid to liquid.
- When atmospheric pressure increases, boiling point __.
- Describe energy and particles during a phase change.
- Describe energy and particles between phase changes.
- steam
- smoke
- liquid nitrogen
- Kool-Aid®
- Compare & contrast solutions, colloids, & suspensions.
- conducts electricity
- explosive
- corrosive
- dissolves in water
- decomposing road kill
- sublimation of dry ice
- grating cheese
- acid rain damage to marble
- Compare and contrast mixtures and compounds.
Atomic Structure & The Periodic Table
Which scientist is responsible for each discovery (50-56)?- Proposed the “billiard ball” model of the atom.
- Proposed the existence of a dense, +charged nucleus.
- Discovered radioactivity.
- Proposed the existence of –charged electrons.
- Proposed the existence of neutrons.
- Developed the “electron cloud” model of the atom.
- Proposed that electrons travel in circular orbits.
- Draw atomic models for billiard ball through electron cloud.
- Draw the Bohr model diagram for magnesium.
- List the subatomic particles & isotope symbol for bromine-80.
- Calculate the average atomic mass of lithium if 1 of 13 atoms is lithium-6 & the other 12 atoms are lithium-7.
- Mendeleev arranged the elements by ___, Mosely arranged them by ___.
- The largest atoms are in the ___ corner of the table. The highest ionization energies are in the ___ corner.
- Which has a larger radius: Li or N?
- Which has a larger radius: Ne or Xe?
- Which has a higher ionization energy: Li or Cs?
- Which has a higher ionization energy: Ba or Rn?
- Draw the electron dot diagrams for Rb and S.
Chemical Bonds
- Why do most atoms form bonds to get 8 valence e-?
- SO3
- FeCl3
- NaNO3
- Form individual molecules.
- Involve the transfer of electrons.
- Form a crystal lattice structure of charged particles.
- Involve the sharing of electrons.
- Have low melting points and strong odors.
- Conduct electricity in solution.
- Usually formed between identical atoms.
- Involve the unequal sharing of electrons.
- Create partial + and – charges within the molecule.
- Involve the equal sharing of electrons.
- Name these molecular compounds: PCl3, SO2, N2O5.
- Name these ionic compounds: LiBr, MgSO4, NaNO2.
- Name these acids: H2SO4, HClO2, HF.
- Write molecular formulas for: carbon tetrachloride, sulfur hexafluoride, dinitrogen monoxide.
- Write ionic formulas for: calcium chloride, aluminum oxide, copper(II) nitrate.
- Write acid formulas for: nitrous acid, phosphoric acid, hydrobromic acid.
Chemical Reactions
- Translate into words: 2SO2(g) + O2(g) 2SO3(g).
- Bond breaking ___ energy, bond making ___ energy.
- 2KClO3 + energy 2KCl + 3O2
- 2Li + 2H2O 2LiOH + H2 + energy
- When substances are mixed, the test tube feels cold.
- Green CuCO3 must be heated in order to break it down in black CuO and CO2 gas.
- In your car’s engine, fuel is burned to produce energy.
- When substances are mixed, the test tube feels warm.
- SiCl4 Si + Cl2
- Li + O2 Li2O
- C3H8 + O2 CO2 + H2O
- H2SO4 + Al Al2(SO4)3 + H2
- Fe + Cl2 FeCl3
- H2CO3 + Ba(NO3)2 HNO3 + BaCO3
- Aluminum sulfide plus chlorine yields aluminum chloride plus sulfur.
- Copper(II) chloride and silver nitrate produce copper(II) nitrate and silver chloride.
Rev. 10/1/01
Exam Review – ANSWER KEY
Rev. 10/1/01
- applied
- pure
- applied
- pure
- Adding salt makes the water boil at a higher temperature.
- Adding salt to water does cause it to boil at a higher temperature.
- Joe correctly tested a single variable and ran repeated trials, but he did not have a control (water without salt) for comparison.
- dependent variable-boiling temperature, independent variable-amount of salt
- 0.24 g/cm3
- 146.7 g
- mm (millimeters)
- kg (kilograms)
- mL (milliliters)
- 0.23 kg
- 435 cm
- 89,600 m
- 304.8 cm
- 1892 mL
- 0.8 g/cm3
- solid
- plasma
- gas
- liquid
- Charles’ law (V&T)
- Boyle’s law (P&V)
- thermal expansion
- condensation
- vaporization (boiling)
- freezing
- sublimation
- evaporation
- melting
- increases
- Potential energy increases since temperature is constant. The spacing between particles increases.
- Kinetic energy increases since temperature is increasing. The particles move faster.
- compound
- heterogeneous mixture
- element
- solution
- Solutions and colloids have particles that don’t settle, whereas particles in a suspension do settle. Colloids and suspensions are heterogeneous mixtures that scatter light, whereas solutions are homogeneous mixtures that don’t scatter light. Solutions have the smallest particles, suspensions have the largest particles.
- physical
- chemical
- chemical
- physical
- chemical
- physical
- physical
- chemical
- Both mixtures and compounds contain more than one element. Mixtures can be physically separated and have a random composition. Compounds can only be chemically separated and have a definite composition.
- Dalton
- Rutherford
- Becquerel
- Thomson
- Chadwick
- Schrödinger
- Bohr
- see Atomic Structure Timeline Lecture Handout
- , atomic# 35, mass# 80, 35 protons, 45 neutrons, 35 electrons
- 6.92 u
- atomic mass, atomic number
- bottom-left, top-right
- Li
- Xe
- Li
- Rn
- Having 8 valence electrons gives most atoms a full outer energy level which makes the atoms more stable.
- covalent
- ionic
Rev. 10/1/01
- ionic
- covalent
- ionic
- ionic
- covalent
- covalent
- ionic
- nonpolar
- polar
- polar
- nonpolar
- phosphorus trichloride, sulfur dioxide, dinitrogen pentoxide
- lithium bromide, magnesium sulfate, sodium nitrite
- sulfuric acid, chlorous acid, hydrofluoric acid
- CCl4, SF6, N2O
- CaCl2, Al2O3, Cu(NO3)2
- HNO2, H3PO4, HBr
- Two molecules of sulfur dioxide gas react with one molecule of oxygen gas to form two molecules of sulfur trioxide gas.
- requires, releases
- endothermic
- exothermic
- endothermic
- endothermic
- exothermic
- exothermic
- decomposition: SiCl4 Si + 2Cl2
- synthesis/combustion: 4Li + O2 2Li2O
- combustion: C3H8 + 5O2 3CO2 + 4H2O
- single replacement: 3H2SO4 + 2Al Al2(SO4)3 + 3H2
- synthesis: 2Fe + 3Cl2 2FeCl3
- double replacement: H2CO3+ Ba(NO3)2 2HNO3 + BaCO3
- single replacement: Al2S3 + 3Cl2 2AlCl3 + 3S
- double replacement: CuCl2 + 2AgNO3 Cu(NO3)2 + 2AgCl
Rev. 10/1/01