Question 6 - Case Based Questions (MCQ) - Chapter 2 Class 10 - Acids, Bases and Salts

A metal is treated with dilute sulphuric acid. The  gas evolved is collected by the method shown in  the figure:  

(a) Name the gas evolved:  

(i) Hydrogen 

(ii) Oxygen  

(iii) Sulphur dioxide gas 

(iv) Carbon dioxide  

Ans. 

When a metal is reacted with dilute sulphuric acid, hydrogen gas is evolved.

The reaction is as follows:

M + H ₂ SO ₄   →MSO ₄ + H ₂ ↑

So, the correct answer is (i) Hydrogen gas.

( b) Is the gas lighter or heavier than air? How will  you test the gas?  

Ans. 

Hydrogen gas is lighter than air . 

Test for presence of hydrogen gas:

• When a burning splinter is brought near the gas, it burns with a pop sound. 
• This pop sound is produced due to the burning of hydrogen gas.

(c) If the metal used above is zinc then write the  chemical equation for the evolution of gas.  

Ans. 

The reaction is as follows:

Zn(s) + H ₂ SO ₄ (dil) → ZnSO ₄ (aq) + H ₂ (g)↑  

(d) What nature of hydrogen is used as a fuel in rocket:  

(i) solid 

(ii) liquid  

(iii) gaseous 

(iv) all of the above  

Ans. 

Liquid hydrogen is used as a fuel in rockets. 

So, the correct answer is (ii) Liquid