Two students analysed water from four rivers.
Each student measured the pH of the river water using a different method.
Table 1 shows the results.
Table 1
River
pH of river water
Method A Method B
W 7 7.4
X 6 6.5
Y 8 8.1
Z 7 7.6
0 1 . 1 Suggest what was used to measure the pH in each method.
[2 marks]
Method A ________________________________________________________
Method B ________________________________________________________
0 1 . 2 Why is it not valid to calculate a mean of the two pH values for each river?
[1 mark]
Tick () one box.
A mean cannot be calculated from only two values.
Each method gives values to a different resolution.
The mean should be calculated for each method using all four samples.
3
(03) G/Jun24/8465/2H
Do not write
outside the
box
Turn over U
0 1 . 3 Complete the sentence.
Choose the answer from the box.
[1 mark]
accurate repeatable reproducible
Method A and method B gave similar results.
This shows that the results are _________________________________.
0 1 . 4 Which river is most likely to be in an area with a high concentration
of sulfur dioxide in the air?
Use Table 1.
[1 mark]
Tick () one box.
W X Y Z
0 1 . 5 Explain your answer to Question 01.4.