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CHEMISTRY FORM 1


i Common Chemistry Laboratory Chemicals
ii Common Chemistry Laboratory Apparatus
iii Safety in the Chemistry Laboratory
iv Why we should learn Chemistry
1. INTRODUCTION TO CHEMISTRY
2. SIMPLE CLASSIFICATION OF SUBSTANCES AND SEPERATION OF MIXTURES
3. ACIDS, BASES AND INDICATORS
4. AIR AND COMBUSTION
5. WATER AND HYDROGEN
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Acids, Bases and Indicators: Reactions of acids with carbonates and hydrogen-carbonates

3.0 Acids, Bases and Indicators


3.4 Reactions of acids with carbonates and hydrogen-carbonates


How do acids react with metal carbonates and hydrogencarbonates?


Materials and substances required
  1. Copper (II) carbonate
  2. Hydrochloric acid
  3. Calcium hydroxide solution (lime water)
  4. Litmus paper
  5. Boiling tube, fitting cork, delivery tube, and a test tube

Set-up reactions of acids nd carbonates and hydrogen carbonates high school chemistry


Open the video, reaction of copper (II) carbonate with hydrochloric acid.

(Courtesy Youtube – copper carbonate + hydrochloric acid by Neha) CuCO3 is green pwd
Keenly observe what happens to the reacting mixture, lime water and blue wet litmus paper.


Questions 3.4(a)

  1. What is the colour of copper (II) carbonate?
  2. Describe the observations made when copper (II) carbonate is reacted with hydrochloric acid.
  3. What is the colour of the gas produced?
  4. What is the colour of the solution formed?
  5. What is the effect of the gas on lime water?
  6. Name the gas produced.
  7. What is the effect of the gas on wet blue litmus paper?
  8. Name the salt formed when copper and chlorine combine.
  9. Three products are formed in this reaction, including water. Write a word equation for the reaction.

Answers to Questions 3.4(a)


NB: Formation of a white insoluble solid with lime water is the test for carbon (IV) oxide. No other gas affects lime water in this manner.
Other carbonates and hydrogencarbonates react with acids in a similar way to produce salt, water and carbon (IV) oxide.



Questions 3.4(b)

From the fact that other metal carbonates and hydrogencarbonates behave like copper (II) carbonate:

  1. Complete the table below to identify the salt solutions (a) to (f) formed when metal carbonates or hydrogencarbonates react with acids.
  2. The solid salts A to F can be obtained by evaporating their solutions to dryness or crystallization. Check and report the colour of salt A from the table of Common Chemistry Laboratory Chemicals, under zinc and its compounds.
  3. Describe the observations made when sodium hydrogencarbonate (a white powder) is reacted with dilute sulphuric acid.
  4. Write a word equation for the reaction between calcium carbonate and nitric acid.
  5. Write a general equation for the reaction between (a) a metal carbonate and an acid (b) a metal hydrogencarbonate and an acid.

Answers to Questions 3.4(b)


At home

Liver salt, a mixture of sodium hydrogencarbonate and citric acid, produces carbon (IV) oxide bubbles when added to water. It is taken as a remedy for acid indigestion, and neutralizes stomach acidity, as the carbon (IV) oxide produced is belched out.


NB: The two substances are chosen because they are safe for the human body.


For curiosity

The Roman numbers in brackets stand for the combining powers of elements, which will be learnt under the structure of atoms. But basically it is the number of links (bonds) through which an atom of one element combines with another element, just like we can hold one another using one hand (I) or two hands (II).