Review Problems for Chemistry 2nd Semester Exam June 2008

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General Review Problem

1.         Oxygen gas can be produced by decomposing liquid hydrogen peroxide (H2O2) into water and oxygen.  12.5 g of H2O2 decompose completely.  Answer the following questions.

a.)     Write a balanced equation for this reaction.

b.)    Mass-Mass problem: Determine the number of grams of water produced by 100% decomposition.

c.)     Mass-Volume problem: Determine the number of liters of Oxygen gas produced by this decomposition, assuming this reaction takes place at STP.

d.)    Mass-heat problem - Determine the new volume of oxygen gas when the temperature is 50.0oC and the pressure is 78.65 cm Hg.

2.         Review the Kinetic Molecular Theory as it describes the Gas Laws and behavior of solids, liquids as well as gases.

Unit 8 Solutions

1. Define:

(a)    Saturated, unsaturated and supersaturated solutions

(b)   Molarity

(c)    The four colligative properties

2.  How many grams of NaOH are there in 350 mL of a 2.50 M solution?

3.      What is the concentration of Na+ ions in 250 mL of solution that contains 2.50 g of Na2SO4 in water?

4.      Write out the overall balanced equation, total ionic equation and net ionic equn for the following reaction:  magnesium hydroxide (aq) + ammonium phosphate (aq) à magnesium phosphate (s)  +  ammonia (g)  + water (l)

Unit 10: Acid/Bases

1.                  Make a list of all strong acids and bases you memorized from the text.

2.                  Arrange the following 0.10 M solutions in order from the lowest pH to the highest pH.  Explain why you have determined this order.

NaOH  NaCl       HC3H5O2      HOCl   H3PO4     KF    Mg(OH)2        CH3NH2 
                                      Ka=1.3x10-5, Ka=       Ka=       Kb=1.4x10-11       Kb=4.4x10-4
                                                            4x10-8   7.5x10-3   

3.         Calculate the pH, pOH and [OH-] for each of the following:

a)  0.020 M perchloric acid

b)  5.2 x 10-4 M NaOH

4.         Define a Brønsted-Lowry acid and base and Arrhenius acids and bases.

5.         A 3.50 x 10-3 M Ca(OH)2 solution is made up.  What is the pH, pOH and [H+] and [OH-] for this solution.

6.         Answer the following questions based upon the titration curve to the right.

(a) In this reaction was the acid added to the base or vice versa? Justify your answer.

 (b) At what volume of added reagent was the equivalence point reached?

 (c) What is the approximate pH of the salt and water at the end point?

 (d) What type of acid and base was this a reaction between, strong or weak?

 

Unit 11: Chemistry of Life

Review notes, quiz and Ch. 27 of your textbook.

Review basic structure of Carbohydrates, Fats, Proteins and Nucleic Acids

Give the basic functions of each of these classes of biomolecules.

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