Review Assignment #5

Due Tuesday, October 31, 10:00 PM (when the CAL closes)

Physics
    Problems form Serway & Beichner
    Chapter 3: 7, 11, 19, 31, 37
    Chapter 4: 3, 9, 10, 11, 14, 20

Calculus
    Problems from Finney, Giordano and Weir
   Chapter 3
        Exercises 3-1: 11-14, 15, 17, 27, 55
        Exercises 3-5: 5, 9a, 11a, 23, 31

Chemistry
    Problems from Oxtoby, Gillis and Nachtrieb
    Chapter 6: 1, 3, 9, 11, 15, 31, 59 and the following two problems:

a) Vitamin C is the simple compound C₆H₈O₆. The amount of vitamin C in a mixture can be determined by a titration with bromine according to the reaction (the "=" sign is the arrow in the reaction),

            C₆H₈O₆ (aq) + Br₂ (aq)  =    2 HBr (aq) + C₆H₆O₆ (aq)

Suppose a 1.00 g "chewable" vitamin C tablet requires 27.85 mL of 0.102 M Br₂ for titration to the equivalence point. How many grams of vitamin C are in the tablet?
 

b) You wish to determine the weight percent of copper in a copper-containing alloy. After dissolving a sample of the alloy in acid, an excess of KI is added, and the Cu²⁺ and I^- ions undergo the reaction:

            2 Cu²⁺ (aq) + 5 I^- (aq) = 2 CuI (s) + I₃^- (aq)

Note that in the above reaction the K⁺ ion, which is present, is not written since it is not participating in the reaction.

The liberated I₃^- is titrated with sodium thiosulfate (thiosulfate is the polyatomic ion, S₂O₃^2-) according to the equation (sodium ion is not written):

            I₃^- (aq) + 2 S₂O₃^2- = S₄O₆^2- (aq) + 3 I^- (aq)

If 26.32 mL of 0.101 M Na₂S₂O₃ is required for titration to the equivalence point, what is the weight percent of copper in 0.251 g of the sample?