CHEM 103 LAB FINAL QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT!!!
Baeyer Test -ANSWER ✔✔reagent: dilute KMnO4
functional group tested: alkenes and alkynes
positive result: purple solution turns to brown precipitate
Bromine/CCl4 Test -ANSWER ✔✔reagent: Br2
functional group tested: alkenes
positive result: yellow-brown solution decolorizes (turns clear)
Measuring boiling point -ANSWER ✔✔need a capillary tube closed on one end,
a minipipet, and a thermometer
place up to three tubes into melting point apparatus at once, increase voltage
slowly, and watch for bubbles to move
turn voltage down to zero and the temperature at which the liquid returns back to
the tube is the boiling point
Density determination -ANSWER ✔✔D = m/v
Mass = measure with a balance in grams
, Volume = measure with a graduated cylinder in mL
Beer's Law formula -ANSWER ✔✔A=abc
-a= molar absorptivity
-b= path length
-c= molar concentration
Color changes in Extraction of Curcumin from Turmeric -ANSWER
✔✔concentration gets lower and color gets lighter after extraction of curcumin
from turmeric
%T to A conversion -ANSWER ✔✔LOG[100/(T%)]
Using curcumin as an indicator -ANSWER ✔✔solutions that turn yellow with
addition indicate acids
solutions that turn orange/red indicate bases
Tollens Test (Silver Mirror Test) and hydrazone derivatives formation -
ANSWER ✔✔Tollens Test:
reagents: silver nitrate, ammonia, sodium hydroxide
functional group tested: aldehydes
positive result: silver mirror
preparation: dissolve n-butylraldehyde in 95% ethanol. add this solution to 2,4-
dinitrophenylhydrazine
*product crystallizes
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT!!!
Baeyer Test -ANSWER ✔✔reagent: dilute KMnO4
functional group tested: alkenes and alkynes
positive result: purple solution turns to brown precipitate
Bromine/CCl4 Test -ANSWER ✔✔reagent: Br2
functional group tested: alkenes
positive result: yellow-brown solution decolorizes (turns clear)
Measuring boiling point -ANSWER ✔✔need a capillary tube closed on one end,
a minipipet, and a thermometer
place up to three tubes into melting point apparatus at once, increase voltage
slowly, and watch for bubbles to move
turn voltage down to zero and the temperature at which the liquid returns back to
the tube is the boiling point
Density determination -ANSWER ✔✔D = m/v
Mass = measure with a balance in grams
, Volume = measure with a graduated cylinder in mL
Beer's Law formula -ANSWER ✔✔A=abc
-a= molar absorptivity
-b= path length
-c= molar concentration
Color changes in Extraction of Curcumin from Turmeric -ANSWER
✔✔concentration gets lower and color gets lighter after extraction of curcumin
from turmeric
%T to A conversion -ANSWER ✔✔LOG[100/(T%)]
Using curcumin as an indicator -ANSWER ✔✔solutions that turn yellow with
addition indicate acids
solutions that turn orange/red indicate bases
Tollens Test (Silver Mirror Test) and hydrazone derivatives formation -
ANSWER ✔✔Tollens Test:
reagents: silver nitrate, ammonia, sodium hydroxide
functional group tested: aldehydes
positive result: silver mirror
preparation: dissolve n-butylraldehyde in 95% ethanol. add this solution to 2,4-
dinitrophenylhydrazine
*product crystallizes
