(c) کو The following volumes of a solution containing 2.20 ppm of aluminium were pipetted into 5 separatory tunnels, each of which contained 5.0 mL of an unknown aluminium solution: 0.0, 4.0, 7.0, 11.0ml. Each solution was then extracted with 3ml aliquots of chloroform containing an excess of 8-hydroxyquinoline. The extracts were then diluted to 25ml and their fluorescerice measured: The results are as follows; ml of std Al Fluorimeter Reading 0.00 4.00 7.00 11.00 12.12 27.16 42.68 57.64 Plot the data, and calculate the concentration of aluminium in the sample. Summer 200

The solubility of suberic acid C6H12(COOH)2 is 0.14 g/100 ml H2O and 0.56g/100 ml ethyl ether at 15 0C.  Calculate the weight of suberic acid removed from 50 ml aqueous solution containing 40 mg acid by extraction with 50 ml ether.  Calculate the weight of acid that would be removed by two successive 25 ml extraction with ether.

A solute with a partition coeffcient (K-[S)s/S]h) of 5 is extracted from 20 mL of phase 1 into phase 2. What volume of phase 2 is needed to extract 90% of the solute in one extraction? ( (a) 0.44 mL (b) 12 ml (c) 36 ml. (d) 72 ml

Human saliva contains the enzyme α-amylase which hydrolyzes polysaccharide acetal linkages.  A soda cracker (containing starch) was carefully ground; the crumbs were distributed evenly between two test tubes.  The first test tube contained only water, while the second contained a 1% solution of α-amylase.  Both mixtures were heated to 35°C for 10 minutes and filtered. The filtrates were tested with iodine solution and Benedict’s solution.  Use the following results to answer the questions below.   Mixture Iodine test Benedict’s Test cracker in water dark blue blue cracker in water and α-amylase red red-orange precipitate a.       Was the starch from the cracker/water mixture hydrolyzed? Was the starch from the cracker in the 1% α-amylase solution hydrolyzed? b.       Which cracker contained reducing sugars?