The colour of an aqueous solution of zinc sulphate as observed in the laboratory is:

Q: The colour of an aqueous solution of zinc sulphate as observed in the laboratory is:

The correct option is **4** (Colourless).

Metals and Non-metals

Displacement Reactions

Options

(1)Green

(2)Yellow

(3)Blue

(4)Colourless

Official Answer

The correct option is 4 (Colourless).

zinc sulphatecolourlessaqueous solution

Marking Scheme

1Identifying the correct option as 4 (Colourless). (1 mark)

Hint

Recall the displacement reaction experiment where a zinc plate is dipped in copper sulphate solution, or an iron nail is dipped in zinc sulphate solution. Zinc salts do not form coloured solutions.

Quick Oral Answer

An aqueous solution of zinc sulphate is colourless.

Analysis & Explanation

An aqueous solution of zinc sulphate ( $ZnSO_4$ ) is completely colourless.

Option 1 (Green) is incorrect because light green is the characteristic colour of an aqueous solution of ferrous sulphate ( $FeSO_4$ ).
Option 2 (Yellow) is incorrect because yellow is not the colour of zinc sulphate; some ferric ( $Fe^{3+}$ ) salts form yellowish solutions.
Option 3 (Blue) is incorrect because blue is the characteristic colour of an aqueous copper sulphate ( $CuSO_4$ ) solution.

Common Mistakes

1Students often confuse the light green colour of iron sulphate ( $FeSO_4$ ) or the blue colour of copper sulphate ( $CuSO_4$ ) with zinc sulphate ( $ZnSO_4$ ).

Interesting Facts

Zinc ions ( $Zn^{2+}$ ) have a completely filled d-orbital ( $3d^{10}$ ), which prevents d-d electronic transitions. This is why zinc salts and their aqueous solutions are colourless, unlike transition metal ions like $Cu^{2+}$ or $Fe^{2+}$ .

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2011?

This question carries 1 mark in the CBSE Class 10 Science 2011 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Metals and Non-metals" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Displacement Reactions" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2011 paper?

This is a MCQ question from Section B in the CBSE Class 10 Science 2011 paper.