Question

Equal lengths of magnesium ribbon are taken in two test tubes 'A' and 'B'. H2SO4 is added to test tube 'A' and H2CO3 in the test tube 'B' in equal amounts:
(a) Identify the test tube showing vigorous reaction.

(b) Give reason to support
your answer.

(c) Name the gas liberated in both the tubes. How will you prove its liberation?

(d) Write chemical equations for both reactions.

(e) Out of the two acids taken above which one will have lower pH value and lower H+ concentration respectively.​

Answer 1

Answer:

a) Test tube A shows more vigorous reaction

b) Sulphuric acid is a stronger acid than carbonic acid. Hence the test tube A produces a more vigorous reaction.

c) Hydrogen gas is liberated in both the tubes. We can prove the liberation of hydrogen gas by bringing a burning splinter near the mouth of the test tube. This produces a pop sound proving the presence of hydrogen.

d) Mg (s) + H2SO4  (aq) → MgSO4 (aq) + H2(g)  

Mg (s) + H2CO3  (aq) → MgCO3 (aq) + H2(g)  

e) Between the two acids, sulphuric acid will have lower pH value compared to carbonic acid.

Carbonic acid will have lower  H+ concentration compared to sulphuric acid.