Students answer two multiple-choice questions on pH.
Answers/responses:
Y9 (08/1997)
Y10 (08/1997)
a)
D (7)
difficult
easy
b)
A (strongly basic)
moderate
difficult
In a recent trial of students completing the online version, responses to this question were similar to those conducted in the 1997 trial above.
Teaching and learning:
Students could practise reading the pH scale from the middle. Reading from 7 upwards to 14 is increasing in strength as a base and reading downwards from 7 to 1 is increasing strength as an acid.
Diagnostic and formative information:
Common error (Year 10)
b)
Option E chosen by 26% of students.
Some students did not separate the scale into an acid and a basic scale beginning in the middle at pH 7. Instead they read the whole scale from 1 to 14 as an acidic scale.
