Study the given table and answer any four questions from (a) to (e):  A student took the samples of four metals A, B, C and D and added the following solutions one by one. The results  obtained have been tabulated as follows: 

Metal Iron (II) Sulphate Copper (II) Sulphate Zinc Sulphate Silver Nitrate
A No reaction Displacement - -
B Displacement - No reaction -
C No reaction No reaction No reaction Displacement
D No reaction No reaction No reaction No reaction

 

(a) Choose the most reactive metal:  

(i) A 

(ii) B  

(iii) C 

(iv) D  

 

Answer

  • According to the reactivity series , among the 4 salts given, Zinc Sulphate is the most reactive
  • Since no metals react with it, we consider the next most reactive solution, Iron (II) Sulphate .
  • Since only B is able to displace Iron from Iron (II) Sulphate, it is the most reactive among A,B,C,D

reactivity-series-of-metals.jpg

So, the correct answer is (i) B

 

(b) Which of the following will displace Cu from its  solution of sulphate:  

(i) A only 

(ii) B only  

(iii) Both A and B 

(iv) None of the above

 

Answer

From the given table, it is seen that 

  • A is able to displace Cu from Copper (II) Sulphate.
  • Since B is more reactive than A , it will also be able to displace Cu.

 

So, the correct answer is (iii) Both A and B

 

(c) Which is the correct decreasing order of reactivity?   

(i) B > A > C > D 

(ii) A > B > D > C  

(iii) D > B > A > C 

(iv) B > A > D > C  

 

Answer

Let us go in order of most reactive to least reactive salt solutions.

  • Zinc solution is the most reactive salt solution here. But no metal reacts with it
  • B is the most reactive element as it is able to displace Iron from its salt solution .
  • A is able to displace copper from its salt solution.
  • C is able to displace Silver from its salt solution.
  • D is the least reactive element, since it does not react at all .

 

So, the correct option is (i) B > A > C > D



(d) The gas produced when dil. HCl is added to a  reactive metal:  

(i) Oxygen 

(ii) nitrogen  

(iii) hydrogen 

(iv) none of the above

 

Answer

The reaction of a reactive metal with dil HCl is as follows:

2M + 2dil HCl→ 2MCl+ H 2

Where M is any reactive metal.

 

So, the correct option is (iv) Hydrogen

  

 

(e) On the basis of sequence of reactions, identify the  most and least reactive elements.  

A + BX AX + B  

C + AY CY + A  

(i) Most reactive: C; Least reactive: B  

(ii) Most reactive: B; Least reactive: C  

(iii) Most reactive: A; Least reactive: B  

(iv) Most reactive: B; Least reactive: A  

 

Answer

  • A is able to displace B from its salt solution BX. So, A is more reactive than B
  • C is able to displace A from its salt solution AY. So, C is more reactive than A and therefore, also more reactive than B

 

Hence, C is most reactive and B is least reactive 

 

So, the correct option is (i) Most reactive: C; Least reactive: B

 

  1. Class 10
  2. Chapter 3 Class 10 - Metals and Non-Metals (Term 1)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo