Question

) Why does an aqueous solution
of an acid conducts electricity? b) blow does the concentration of
Ilydronium ions 11130+1 change when a solution of an acid is diluted? c)
Which has the higher pl I value, a concentrated or dilute solution of !ICI?
d) What could you observe on adding dil. hCI to- (i) Solid sodium carbonate placed in a test tube? (ii) Zinc metal in a test tube?

Answer 1

Answer:

Explanation:

a) Acids undergo dissociation in aqueous solution to form H+ ions. When electricity is passed through an aqueous solution of an acid, the H+ ions reach the cathode and each H+ ion picks up one electron from the cathode to form H2 gas. Because of this reaction, an aqueous solution of acid conducts electricity.

b) The concentration of hydronium ions decreases when an acid is diluted because on adding water the H+ ions of the acid and hydroxyl ions of water react to form water molecules and the concentration of hydronium ions decreases.

H+ + H2OH3O+

H+ + OH-H2O

c) The pH ranges between 0 and 14.

0 is classified as the most acidic.

As the acidity decreases, the substances become basic.

7 is called the neutral value.

Based on this, it is clear that hydrochloric acid that is concentrated is much more acidic than the hydrochloric acid that is dilute.

d)A colourless gas is evolved which turns limewater milky and turns moist blue litmus paper, faint red.

The gas is Carbon dioxide

When dilute hydrochloric acid is added to granulated zinc placed in a test tube, a colourless and odourless gas is evolved with bubbles.