Lab 6

Question 1

what is the color of the product (4-methylumbelliferone) in this experiment

Answer 1

cocaine
white, looks like snow

Question 2

what was in test tube 1, 2 and 3?

Answer 2

1: product and ethanol
2: product, ethanol and HCl
3: product, ethanol and NaOH

Question 3

what was the fluorescence observation of test tube 1, 2 and 3?

Answer 3

1: light blue color
2: mint green color
3: royal blue in color

Question 4

can melting point identify a compound?

Answer 4

it can help identify it but will not alone enable us to identify the compound

Question 5

what would it mean if the melting point had a wide range in temperature rather than a narrow range of 0.5 to 1°C?

Answer 5

wide range indicates the substance is impure, small impurities cause the melting point to lower drastically and cause a wide range in melting point
0.5 to 1°C indicates high purity of the sample

Question 6

how do you identify the limiting reactant?

Answer 6

compare the number of moles (smaller mol is the limiting reactant)

Question 7

was the reaction endothermic or exothermic to create the end product?

Answer 7

endothermic

Question 8

what did the dowex beads do?

Answer 8

catalyst
reused
(more green because its more energy efficient)

Question 9

why did we use hot water at the last step of the synthesis?

Answer 9

to form the precipitate, it allows the proton transfer to occur, dissolves excess reactants and therefore allows the product to be more pure