Solution Quiz #1
Grade is a multiplier: you'll get 5% bonus on the regular quiz for each of the following you get correct.
All %-solutions are weight/volume if a solid is involved; or vol/vol if only liquids.

  1. On the side-shelf you see what appears to be about a liter of a 10% aqueous solution of glycerol (molecular weight = 92). How much of it should you use to make 500 ml of a 1% glycerol solution? .
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  2. You are told to make a 2.5% agar solution for a certain type of petri plate experiment. How much agar powder should you use to make 200 ml? .
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  3. You want to test various compounds for their osmotic consequences on the growth rate of brewer's/baker's yeast (Saccharomyces cereviseae). You want to use glycerol at 0.1M. How much glycerol should you use to make 300 ml of the appropriate growth medium? .
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  4. On the side-shelf you see two full liter containers labelled NaCl (molec wt = 58): one contains dry granules, and the other contains 1.5% (aqueous sol'n). How much of which should you use to make 250 ml of a 2% solution? .
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  5. The major shampoo detergent "cetavlon" is more lethal to bacteria than is the antibiotic streptomycin. You need to determine the minimum lethal concentration on E. coli. You have been told it is about 0.0002%. You have a bottle containing about 50 ml 0.3% cetavlon (aqueous). How should you make a tube containing 1 ml of 0.0003% cetavlon? (Due to a severe drought, you have only 90 ml of water to use for dilutions.).
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