Chemistry Reference
In-Depth Information
2
1.03
0.92
0.80
0.80 0.82
1
0.71
0.55 0.58 0.58
0.58
0.43
0
1.1
1.2
1.3
1.4
2.1
2.2
2.3
2.4
2.5
3.1
3.2
-1
-2
2
1
0
1.1
1.2 1.3 1.4
2.1
2.2
2.3
2.4 2.5 3.1
3.2
-1
-2
Fig. 9.17
Students' evaluation of the question: How interesting did you find the single question?
Meaning of the ordinate numbers: +2
¼
very interesting;
2
¼
totally uninteresting.
Above
: all
students,
below
: boys (
black
) and girls (
white
). Data from ([
2
], p. 143)
The following answers were obtained (number of students in percent that gave
the correct answer for the item):
- Which of these pure substances are white solids?
NaCl
MgO
KOH
CaCO
3
KNO
3
All correct
71%
57%
12%
10%
7%
0%
- Which substances are poorly soluble in water?
Zn
S
MgO
CaCO
3
All correct
50%
40%
19%
7%
0%
- Which substances react alkaline in aqueous solution?
KOH
Ca
MgO
Na
2
CO
3
CaCO
3
All correct
22%
12%
10%
10%
7%
0%
- Which substances react with acids generating a gas?
Ca
Zn
CaCO
3
Na
2
CO
3
All correct
14%
12%
10%
7%
0%
