Review Sheet for Chemistry* First Semester Final s1

Review Sheet for Chemistry* First Semester Final

Refer to your class notes, worksheets, and the textbook to complete this review sheet. Study early so that you will have time to ask questions about what you don’t understand. Do not forget to use your study guide from the first quarter exam to also help you review for your semester final. If you do not have your first quarter review packet you can get another (and the answers) at: http://www.ncusd203.org/north/depts/science/chemistry/common_references.htm

(* The study of matter and the changes it undergoes)

Matter: Anything that takes up space and has mass

Ø  Physical Changes and Chemical Changes

Define each. How can you tell the difference between the two?

Classify the following as physical or chemical changes:

a. spoiling of milk ______

b. bending wire ______

c. cutting paper ______

d. rusting of a nail ______

Ø  Put the following into a graphic organizer/flowchart and define each:

·  Matter

·  Pure substances – elements and compounds

·  Mixtures – homogeneous (solutions) and heterogeneous

Identify the following as pure substances, homogeneous mixtures or heterogeneous mixtures:

a. copper ______

b. sweetened tea ______

c. sand and water ______

d. calcium carbonate (CaCO3) ______

Ø  Sketch particles in the three states of matter. How close are the particles and how much do they move?

Ø  Calculations using the Law of Conservation of Mass for Reactions

4g H2 + ?? g O2 → 36g H2O

Atom

Ø  For this Carbon–14 isotope,

·  Atomic number = _____, Mass number = _____,

·  # of protons = _____, # of electrons = _____, # of neutrons = _____.

Ø  Atomic Masses: What is the difference between the mass number for Carbon–14 and carbon’s atomic mass of 12.011 amu?

Ø  Calculate the atomic mass of lithium is one isotope has a mass of 6.0151 amu and a percent abundance of 7.59% and a second isotope has a mass of 7.0600 amu and a percent abundance of 92.41%.

Ø  Atomic Models:

Philosophers: Democritus (believed in atoms) and Aristotle (didn’t believe in atoms)

Scientists: What was the contribution of each one’s atomic model? Draw a model of each.

·  John Dalton

List the four postulates of Dalton’s Atomic Theory:

·  J.J. Thompson

·  Earnest Rutherford

·  Niels Bohr

·  Quantum mechanical model (Werner Heisenberg):

§  Energy levels (n=1, 2, 3, 4,…) – represented by periods on the periodic table

§  Sublevels: (s, p, d, f) – represented by blocks on the periodic table

§  Orbitals – region of space where up to 2 electrons may be found

Ø  Electron Configurations. What element has the configuration [Ne]3s23p1? _____

·  What does the 3 mean in 3s2 ?

·  What does the s mean?

·  What does the 2 mean?

·  How many valence electrons will an atom of this element have?

·  How many electrons will an atom of this element lose to form an ion? Why?

·  Write out the electron distribution according to Hund’s rule. The 1s2 sublevel is done for you.

1s2_↑ ↓___

2s2 ____

2p6 ______

3s2 ____

3p6 ______

Ø  Emission (or bright-line) Spectrums

·  What is needed for an electron to “jump” to a higher energy level?

·  What happens when an “excited” electron falls back to its ground state?

·  What does an emission spectrum allow one to do?

Ø Characteristics of subatomic particles

Periodic trends

Ø  Locate or define parts of the periodic table:

·  Groups

·  Periods

·  Transition metals (d & f blocks) vs. Representative Elements (s & p blocks)

·  Alkali metals, Alkaline Earth metals, Halogens, Noble Gases

Ø  Periodic Trends: Increasing or Decreasing from top to bottom or left to right?

Ø Elements in the same ______have similar physical and chemical characteristics because the

(group, period)

they have the same number of ______.

(atoms, protons, neutrons, electrons, valence electrons)

Ø  Draw a electron dot diagram (or Lewis Dot structure) for Be and for N showing the correct number of valence electrons

Ø  From their positions on the periodic table, what charges would the ions of Be and N have?

Ø  Properties of Metals vs. Nonmetals vs. Metalloids

Ionic vs. Molecular Compounds:

Ionic bonds are formed when a ______and a ______combine.

Metals lose electrons and form ______while nonmetals gain and electrons form ______.

Molecular compounds form when a ______and a ______combine as they share electrons.

Identify the following pairs of atoms as potentially forming an ionic or molecular compound:

Mg and Cl ______I and F ______P and Cl ______

Ag and S ______K and Br ______Sn and O ______

Naming Molecular and Ionic Compounds

Ø  Naming molecular compounds

·  Name: N2O: ______and NO2 ______

Ø  Naming Ionic Compounds

·  Name: Li2O ______and (NH4)2SO4 ______

·  Name: FeO ______and Sn3(PO4)4 ______

·  Name: NaHCO3 ______and CuCl2 ______

Formulas of Molecular and Ionic Compounds

Ø Write formulas for the following molecular compounds:

·  Water ______silicon dioxide ______

Phosphorous trihydride ______dioxygen difluoride ______

Lead (II) hydroxide ______chromium (III) sulfate ______

Ø Write formulas for: Ba2+ with OH– ______iron (III) sulfide ______

Na+ with OH– ______NH4+ with PO43– ______magnesium oxide______

Chemical Reactions

Ø Define what is meant by the term chemical reaction.

Ø In the following chemical equation, identify the reactants and the products.

3Ba(C2H3O2)2(aq) + 2Na3PO4(aq) à Ba3(PO4)2(s) + 6NaC2H3O2(aq)

·  In the above chemical equation, what do the symbols (aq) and (s) stand for? What would the symbols

(l) and (g) stand for in a chemical equation?

Ø Chemical reactions can often be classified as one of five types. Write the general form for each type of reaction.

·  Direct Combination (or synthesis):

·  Decomposition

·  Single-Replacement

·  Double-Replacement

·  Combustion

Ø Using the five types of reactions listed above, classify AND balance the following equations:

___Na(s) + ___Br2(l) à ___NaBr(s) ______

heat

___CH4(g) + ___O2(g) à ___CO2(g) + ___H2O(g) _______

___K2CrO4(aq) + ___Ba(NO3)2(aq) à ___BaCrO4(s) + ___KNO3(aq) ______

electric

___H2O(l) à ___H2(g) + ___O2(g ______

current

___Al(s) + ___Fe2O3(s) à ___Al2O3(s) + ___Fe(s) ______

___H2(g) + O2(g) à ___H2O(l) ______

heat

___C8H18(l) + ___O2(g) à ___CO2(g) + ___H2O(g) ______

Predicting Products:

Using the activity series, will the following reactions occur?

2Al (s) + Fe2O3 (aq) à Al2O3 (aq) + 2Fe (s) y or n ______

Zn (s) + 2HNO3 (aq) à Zn(NO3)2 (aq) + H2 (g) y or n ______

Pb (s) + MgO (aq) à PbO (aq) + Mg (s) y or n ______

Predict the products of the following reactions. Using the solubility table, predict if there will be a precipitate. If there is a precipitate, what is it?

Reaction Products Precipitate (Y/N) What is

Precipitate?

AgNO3 (aq) + KCl (aq) à

(NH4)PO4 (aq) + CaCl2 (aq) à

NH4NO3 (aq) + NaCl (aq) à

The MOLE!

Molar Mass:

What is the definition of molar mass?

Calculate the molar mass of the following:

Na:

Fluorine gas:

Mg(OH)2:

Methane- CH4:

Mole Conversions:

1.  Find the volume of 2.00 moles of hydrogen sulfide, H2S at STP.

2.  How many moles are there in 37.0 L of sulfur dioxide, SO2 at STP?

3.  How many particles are there in 2.00 moles of acetylene, C2H2?

4.  What is the mass of 5.00 moles of acetylene, C2H2?

5.  How many moles are in 72.0 g of sodium chloride, NaCl?

6.  How many particles are there in 3.00 L of carbon monoxide, CO at STP?

7.  Find the number of molecules in 1.26 g of phosgene, CCl2O.

8.  How many liters are in 128 g of nitrogen gas, N2?

9.  Find the number of grams in 8.20 x 1024 formula units of KCl.

Stoichiometry Practice

Hydrogen sulfide, a foul-smelling gas, is found in nature in volcanic areas. The balanced chemical equation for the burning of hydrogen sulfide is given below. Interpret this equation in terms of the interaction of the following three relative quantities.

1.  The coefficients in this balanced reaction can represent

a.  Number of moles

b.  Number of liters

c.  Number of particles

d.  All of the above

2 H2S (g) + 3O2 (g) à 2SO2 (g) + 2 H2O (g)

2.  How many moles of sulfur dioxide will be produced when 6 moles of oxygen react completely?

3.  What is the mole to mole ratio of…

a.  Dihydrogen sulfide to oxygen?

b.  Oxygen to water?

c.  Dihydrogen sulfide to sulfur dioxide?