Reactivity Series — Homi Bhabha Exam Chemistry MCQs with Solutions
Free Homi Bhabha Exam Chemistry Reactivity Series MCQs with step-by-step solutions (7 questions). Part of Metals & Non-Metals. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Reactivity Series · medium · theory
In the reactivity series of metals, the most reactive metal among the following is:
A. potassium ✓ Correct
B. gold
C. iron
D. copper
Solution: Potassium is near the top of the reactivity series and is the most reactive of these.
Q2 — Reactivity Series · medium · theory
The least reactive metal among the following is:
A. gold ✓ Correct
B. zinc
C. iron
D. magnesium
Solution: Gold is at the bottom of the reactivity series and is the least reactive.
Q3 — Reactivity Series · hard · theory
When an iron nail is dipped in copper sulphate solution, the blue colour fades and the nail turns brownish because:
A. iron is more reactive and displaces copper ✓ Correct
B. no reaction occurs
C. copper is more reactive than iron
D. iron dissolves without reaction
Solution: Being more reactive, iron displaces copper from copper sulphate (Fe + CuSO₄ → FeSO₄ + Cu).
Q4 — Reactivity Series · hard · theory
Metals placed above hydrogen in the reactivity series can displace hydrogen from dilute acids. Which metal does NOT react with dilute hydrochloric acid?
A. Zinc
B. Magnesium
C. Copper ✓ Correct
D. Iron
Solution: Copper lies below hydrogen in the series, so it does not displace hydrogen from acids.
Q5 — Reactivity Series · medium · theory
Sodium and potassium are stored under kerosene because they:
A. are very heavy
B. are non-metals
C. do not react at all
D. react vigorously with air and water ✓ Correct
Solution: These highly reactive metals react vigorously (even catch fire) with air and moisture, so they are kept under kerosene.
Q6 — Reactivity Series · hard · theory
A more reactive metal can displace a less reactive metal from its salt solution. Which pair will react?
A. Copper added to zinc sulphate solution
B. Silver added to copper sulphate solution
C. Zinc added to copper sulphate solution ✓ Correct
D. Gold added to iron sulphate solution
Solution: Zinc is more reactive than copper, so it displaces copper from copper sulphate.
Q7 — Reactivity Series · medium · theory
The correct order of decreasing reactivity is:
A. Zn > K > Cu > Fe > Na
B. Cu > Fe > Zn > Na > K
C. Fe > K > Cu > Na > Zn
D. K > Na > Zn > Fe > Cu ✓ Correct
Solution: The standard reactivity series decreases as K > Na > … > Zn > Fe > … > Cu.