Answer:

Aim:

To study the properties of acids (dilute HCl) and bases (dilute NaOH) by their reactions with the following:

Litmus solution (red/blue)

Zinc metal

Solid sodium carbonate

Materials required:

Test tube

Test tube stand

Cork

Test tube holder

Boiling tube

Droppers

Flat bottom flask

Burner

Matchbox

Beaker

Thistle funnel

Litmus paper/solution

Fresh lime water

Glass rod

Dilute HCl

Dilute NaOH

Zinc granules

Solid sodium carbonate

Theory:

What is acid?

Chemical species which donate protons or release H+ ions when dissolved in water are called acid. They turn blue litmus solution to red colour.

Hydrochloric acid reacts with zinc metal to produce zinc chloride and hydrogen gas. The reaction is given below:

Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

Hydrochloric acid reacts with Na2CO3 to produce carbon dioxide and turns the lime water milky as it forms calcium carbonate. The milkiness formed disappears when more than necessary carbon dioxide is passed through the solution. The reaction is as follows:

Na2CO3(s/aq) + 2HCl(aq) → 2NaCl(aq) + H2O(l) + CO2(g)

Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l)

CaCO3(s) + H2O(l) + CO2(g) → Ca(HCO3)2(aq)

Verified answer

Explanation:

Machenism:-

Step-1-

Take a test with small zinc granules and a acid (e.g. hydrochloric acid) close the mouth of the test tube with a cork.

Step-2-

Connect it to a beaker of soapy water with the help of a tube.

Observation:-

We will observe some bubbles coming out from the beaker. If we bring a burning matchstick near to it, it will burn with a pop sound.

Conclusion:-

Metals react with acid and produce hydrogen gas.

[tex]\sf Zn +2HCl \longrightarrow ZnCl + H_2 \uparrow[/tex]

Metals react with bases in the same way and produce hydrogen gas.

[tex]\sf Al+NaOH \longrightarrow NaAlO_2+H_2 \uparrow[/tex]