Investigating the effect of adding salt to boiling water

1
Investigating the effect of adding salt to
boiling water
2
Hypothesis 1. That the temperature will rise
steadily for the whole heating period
Possible Hypothesis (guess for what will happen)
Hypothesis 3. That adding salt will lower the
boiling point
Hypothesis 4. That adding salt will raise the
boiling point
Hypothesis 2. That the salt will have zero
effect on the outcome
3
temperature
beaker
thermometer
bunsen burner
gauze
tripod
4
Procedure Half fill beaker with tap water Add
salt (some groups agree not to add salt) Stir
(use the stirring rod) Add ice leave to stand for
2mins Record temp (time zero) Start stop
clock Heat with mid blue flame Record temp each
min until boiling Record temp change during
boiling for five minutes Leave equipment to cool
for 5 mins before clear up
5
Group Results Table
time
temp oC
(min)
10-15
start
0 1 2 3 4 5 6 7 8 9 10 11 12 13
6
Fri 1st Feb 2008
Class photos of this session can be viewed during
the lesson
7
SALT
GROUP
START T
END T
8
100
y
o
time
x