Chem 212
Quiz 3h
p.1
NAME__________________________________
Alkanes & Alkenes reactions, properties (20 pts)
1.
(14 pts) Draw the structures of the organic products of the following reactions. Do not draw
the same structure more than once:
HO
O 2, spark
CO2 + H2O
Br
HBr
Br2
(You do not need to show the trans
relationship between the bromine atoms)
Br
Br
Cl
Cl 2, light
+
Cl
+
+
HCl
Cl
Br2, light
Br
H2, Pd
OH
H2O, H 2SO 4
2. (3 pts) Put each of the following substances in order of melting point, from lowest to highest,
and explain your reasoning clearly: 2,2,3-trimethylbutane; decane; 2,3-dimethylpentane;
heptane; 3-methylhexane.
2,2,3-trimethylbutane 2,3-dimethylpentane
C7H16
C7H16
2-methylhexane
C7H16
heptane
decane
C7H16
C10H22
For molecules with the same chemical formula (and therefore molecular weight) more branching of the alkane
leads to lower melting point because of disruption of Van der Walls interactions. Higher molecular weight
molecules generally have higher melting points.
3. (3 pts) Briefly describe what you would observe for a positive bromine test for unsaturation,
and a positive permanganate test for unsaturation.
A positive bromine test is seen when the red-brown color of bromine disappears upon addition of bromine to a
sample. A positive permanganate test is seen when the purple color of permanganate solution turns to a brown
precipitate of manganese dioxide.