Les modèles et la modélisation de la réaction acide-base dans le ...

other hand most of students had difficulty to identify “producing beer “as CP while
“manufacture an indicator” appeared easy.
Although many students establish the difference between PP and CP (answers to
question 1) they still have a little difficult to distinguish PP to CP among a list of
phenomena. The statistical results show a significant difference between students
mean CP values and students mean PP values [t (9) = -9.478, p= .000].Therefore
chemical phenomena were more difficult to identify than physical phenomena.
Was there any connection between CP and CR?
The mean value “a” CP or CR is the higher than each other’s. The statistical analysis
show that the difference between “a” CP value and “i” value CP is not significant
neither “a” CR value nor “c” CR value. But the difference between CP values to each
other’s is still significant expected “c-g-h” CP values which seemed statistically same
values too. Therefore the statistical analysis shows two different groups of CP values:
“a = i” group and “c=g=h” group; and different groups of CR values “a=c” and “g=h=i”.
The assertion “h” still has the lowest value and “a” the highest one for CP and CR. It
seemed easy to students to identify “burning paper” as a chemical phenomenon and
to connect it to a chemical reaction however “producing beer” was very difficult to
identify as CP and to connect to a CR.
Otherwise t-paired samples test indicated that the difference between mean CP and
mean CR is very significant [ for a: t (9) = 18.319, p= 0.000; for c:t(9) = 6.721 , p =
0.000; for g : t(9) = 9.362, p = 0.000; for h: t(9)= 11.692, p = 0.000; for i: t (9)= 14.630;
p = 0.000].
On the other hand many students considered those phenomena occur physical,
chemical or biological reaction. As a result few students were able to say that
“producing beer” is a” fermentation” reaction. All the Students of six schools have
failed this question. Most of them considered it as a biological reaction.
If we pursue the analysis we can see that the difference between the Student who
identify correctly CP with CR is significant [t (9) = 18.402, sig. 2-talied = 0.000). The
students CR knowledge seems to be mediocre. Students' knowledge of CR is poorer
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