Change of State
CH 30S
I.
Use the followjjrgcharr. and answer the questions that follow
Substance
Meltmg Point*
Boiling Point
0 °c
Water
Para -dichloro
benzene
100 °C
:
53 °C
••
1
6
174 C '
r
1
L
Napthalene
, Methyl Alcohol.
Mercury
80 °C
218 °C
*98 °C
165 °C
-39 °C
•: » 357 °C
,
'
a) . What will the state of the following substances be under the
following conditions? Solid (s), Liquid (L) or Gas (G) ?
Substance
0°C
.Water ,
Conditions
Room
55 °C
Temp
100 °C
fi
L
,r
L
Napthalene
Para -dichloro
benzene
Methyl Alcohol
I
u
Mercury
400 °C
1
1
l
b) In what order would Ice, Para and Naptha melt?
c) In what orler would Jtete}, ^ r a ^ d l l p t | ^ r r ^ ^
7
^
^
Which ofthe following has the highest Melting point?
a) 0.02 g of Naptha
b) 2.0
2^0gof
Naptha T
Aiejn't At*l4*r^
g of Naptha
c) 20 g of Naptha
3. What would be the freezing point of Mercury and methyl Alcohol?
4. What is the Freezing Point ofthe following substances?
T
e
m
P
7
o
C
c)
T
e
m
P
9
60:
5o-
ft,.
c
3o-
(min)
a) Which of the above could be Para?
b) Why do some graphs* have two plateaus?
V• f ;
Wi
c) Indicate on each graph where solids, solids and liquids and liquids co-exist.
5. A student melted a material using one burner ,, 130 ml of water as a
water bath, 5.00 grams of material and took temperature readings
every 0.5 minute interval.
The data was graphed
•
i — i — . — i
•
1
1
«
1
»-
0 2 4 6 8 10 12 14 16 18 20
Indicate on the graph what you would expect to happen if:
a)
two burners were used?
b)
i f 10.00 g of material were used?
c)
i f 1.00 g of material was used?
d)
if ^ .00 grams of the same material was cooled from 70 °C to 40 °C?
,
6. Which of the folldwing variables afTect the Freezing Point of a substance?
Variable
a)
Heat of the burner
b) Time of cooling
c)
Amount of Material
d) Type of Thermometer used
e) Type of material
f)
Effect on the Freezing Point
Strength of intermolecular
bonds
Mane