In the investigation the learners took sodium thiosulphate of different concentration and reacted it with hydrochloric acid of constant concentration. They recorded the
time taken for the mark X on the paper to disappear. Their result is tabulated
below.
Trial
1
2
3
4
Concentration
Na S, Os(mol. dm)
0.15
0.09
0.06
0.03
Time taken for the
X to disappear in
43
66
100
240
5.1
Define the term reaction rate
52
For the experiment described above, name the
5.2.1
Independent variable
5.2.2
ONE control variable
5.3
Write down the NAME OR FORMULA of the substance responsible for the
cloudiness
5.4
Consider the table of results and write down which trial (1. 2. 3 or 4)
occurred at the highest reaction rate?
5 5
Draw a graph of concentration of sodium thiosulphate against time for the
mark X lo disappear in the ATTACHED GRAPH SHEET
5.6
Use the graph to make a conclusion for the above Investigation
5.7
Name TWO other ways in which the rate of this reaction can be increased.
(2)what is the name of formula of the substance responsible for cloudiness ​