2
3
med through reactions between acids and bases.
Most of the salts are readily soluble in water.
Salts do not conduct electricity in their solid state. However, molten salts
and solution of salts in water conduct electricity
Let us now perform an activity to show that solutions of salts, in water, can
conduct electricity.
chem
gb
Activity 4
Take a beaker and fill it half with water. Dissolve
some common salt (sodium chloride) in this water
Connect two graphite rods with the two terminals
of a battery, with a zero watt LED bulb in between,
as shown in the figure. Now dip these graphite rods
in the solution of sodium chloride. The bulb starts
glowing indicating the flow of electric current
This shows that a solution of sodium chloride can
conduct electricity,
Soshire
51
Answers
Explanation:
Acids Bases and Salts - NCERT Questions
Q 1.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tubes?
SOLUTION:
Take three small pieces of red litmus paper. Put one drop each of the given solutions on these litmus papers.
The liquid which turns red litmus into blue is a basic solution.
Divide the blue litmus paper so formed into two parts. Put one drop each of the other two liquids separately on these two pieces of litmus paper.
The solution which turns blue litmus paper red is acidic solution.
The solution which does not affect the colour of litmus paper is water.
Q 2.
Why should curd and sour substances not be kept in brass and copper vessels?
SOLUTION:
The curd and sour substances are acidic. They will react with brass (alloy of copper and zinc metals) and copper vessels and will spoil the vessels.
Q 3.
Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?
SOLUTION:
Hydrogen gas is liberated when an acid reacts with a metal. For example, when zinc metal reacts with dil.HCl, hydrogen is evolved and salt zinc chloride is formed as:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
It can be tested by bringing a burning candle near the gas. The candle continues burning with a pop sound.