Thursday, 22 January 2015

7.1.3 - Laboratory Activity : Properties of an acid


Laboratory Activity 7.1.3:
Properties of an acid
Aim: To study the chemical properties of acid
Material:
» Magnesium ribbon
» Copper (II) oxide powder
» Hydrochloric acids
» Lime water
» Copper(II) carbonate

Apparatus:
» Test tube
» Holder
» Delivery tube
» Wooden splint
» Spatula
» Bunsen burner
Procedure:

The animation below shows the arrangement and results of the experiment.

(A) Reaction with magnesium
1. 10cm3 dilute hydrochloric acid is poured into a test tube.
2. A piece of magnesium ribbon is dropped into the test tube.
3. The test tube is heated gently.
4. The gas evolves is tested with a lighted wooden splinter.

(B) Reaction with copper (II) carbonate
1. Several pieces of copper carbonate are placed into a test tube.
2. 10cm3 dilute hydrochloric acid is poured into the test tube.
3. The test tube is heated gently.
4. The gas evolves is tested with lime water.

(C) Reaction with copper(II) oxide
1. 10cm3 dilute hydrochloric acid is poured into a test tube.
2. A spatula of copper(II) carbonate is added into the test tube.
3. The test tube is heated gently.
4. All observations are recorded.
Results:

Test Observation
(A) Reaction with magnesium Effervescence occurs. Gas evolves produces a 'pop' sound with a lighted wooden splinter.
(B) Reaction with copper(II) carbonate Effervescence occurs. Gas evolves turns the lime water chalky.
(C) Reaction with copper oxide(II) Black copper(II) oxide powder dissolves to form a blue solution.
Discussion:

An active metal [magnesium] reacts with dilute acid[hydrochloric acid] to produces hydrogen gas and salt.
HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)

A dilute acid produces carbon dioxide, water and a salt from all carbonate.
HCl(aq) + CuCO3(s) → CuCl2(aq) + H2O(l) + CO2(g)

A dilute acid react with base or alkali to form a salt and water only .
2HCl(aq) + CuO(s) → CuCl2(aq) + H2O(l)
Conclusion:

Acids react with active metals like magnesium to produce a salt and hydrogen gas.

Acids react with carbonate to produce a salt, water and carbon dioxide.

All acids react with a base or alkali to form a salt and water only.


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