Chem 212 Quiz 0c p.2

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Chemistry 212 Background Take-Home Quiz

This quiz covers topics from General Chemistry that are particularly important for Survey of Organic and Biochemistry. Point values for each question reflect the relative importance of the material to the course. The course description for the prerequisite course is printed below.

CHEMISTRY073 0201 - General Chemistry I
Topics include the periodic table of the elements, atomic structure, basic concepts of quantum theory, bonding, stoichiometry of compounds and reactions, thermochemistry, the gaseous state, basic concepts of the liquid and solid states, solutions, acids and bases. Writing assignments, as appropriate to the discipline, are part of the course

1.  (atomic structure) 6 pts Write the number of total electrons and number of valence electrons for each of the following:

Total e- Valence e-

  1. C ______
  1. Na+ ______
  1. S2- ______

2.  (atomic structure) 6 pts What charge would result in each of the following situations:

  1. N with 10 electrons around it
  1. Li with 10 electrons around it
  1. Na with 19 electrons around it

3.  (atomic structure, periodic table) 6 pts The electronic configuration of neon in it's ground state is 1s22s22p6. Give the electronic configuration for each of the following:

a. ground state of Ne+

b. ground state of F-

c. ground state of C

d. ground state of K+

e. an excited state of Ne

f. an excited state of Be+

4.  (Lewis structures, VSEPR) 10 pts Draw Lewis dot diagrams (Lewis structures) for each of the following molecules, and predict the shape of the molecule as one of the following: a) tetrahedral, b) tetrahedral/triangular pyramidal, c) tetrahedral/bent, d) triangular planar, e) triangular planar/bent, e) linear.

a. CH4 d. NH3

b. H2O e. BF3

c. H2Se f. BeH2

5.  (unit conversions) 2 pts Convert each of the following into the units indicated

a. 34 mg = g

b. 270 mL = mL

c. 12.5 mL = mL

d. 34 mmol = mol (mol = moles)

e. 0.00001 kg = mg

6.  (solutions) 8 pts Which of the following diagrams best represents the molecular concept of sodium chloride dissolved in water? Explain what is wrong for each of the other diagrams.

7.  (nomenclature) 3 pts Give the names of each of the following inorganic acids, bases, or salts and state whether it is an acid, base, or salt:

a.  H2SO4

b.  HNO3

c.  NaOH

d.  NH4Cl

8.  (nomenclature) 3 pts Give the formula for each of the following inorganic salts:

a.  Magnesium sulfate

b.  Potassium bromide

c.  Calcium chloride

9.  (acidity, basicity) 10 pts Write balanced chemical equations for each of the following acid-base reactions:

  1. Calcium hydroxide plus hydrochloric acid.
  1. Sulfuric acid plus ammonia
  1. Water plus nitric acid

10.  (stoichiometry) 7 pts For reaction 9a above, how many grams of calcium hydroxide are required to react with 36. g of hydrochloric acid? Show your work.

11.  (stoichiometry, solutions) 6 pts For reaction 9b above, how many mL of 1.0 M sulfuric acid is required to react with 2.5 M ammonia? Show your work.

12.  (density, molecular weight, stoichiometry, percent yield, limiting reagent) 7 pts See the reaction below. A 3.144 mL sample of 1,2-ethanediol (ethylene glycol, density 1.10 g/mL) was heated with 5720 mL of acetic acid to form a diester, which was then separated from the reaction mixture, purified, and dried. The diester product weighed 5.3 grams. What is the theoretical yield of the diester that could be obtained? What was the percent yield actually obtained? Show your work.

HOCH2CH2OH + 2 CH3COOH ® CH3COOCH2CH2OOCCH3 + 2 H2O

ethylene glycol acetic acid a diester