Question

Aluminium sulphate and copper sulphate solutions were taken in two test tubes I and II, respectively. A few pieces of iron filings were then added to both the solutions. The four students A, B, C and D recorded their observations in the form of a table as given below:

Student	Aluminium Sulphate Solution I	Copper Sulphate Solution II
A	Colourless solution changes to light green	Blue colour of the solution is retained
B	Colour of the colourless solution does not change	Blue colour of the solution changes to green
C	Colourless solution changes to light blue	Blue colour of the solution changes to green
D	Colour of the colourless solution remains unchanged	Blue colour of the solution fades away

The correct set of observations has been recorded by student. Who recorded the correct observation? Give reason.

Answer 1

Aluminium sulphate is colourless and it does not undergo any change as iron does not react with it. Copper sulphate solution is blue which changes into green due to the formation of FeSO₄ which is green in colour