Experiments on Properties Acids and Bases

Experiments on Properties of Acids

Properties of acids and bases are studied with the help of their reactions with

  1. Litmus solution

  2. Zinc and

  3. Solid sodium carbonate.


Materials Required For All Experiments

  1. Test tubes,

  2. Dropper

  3. Test tube stand and holder

  4. Matchbox

  5. Burner

  6. Flat bottom flask

  7. Beaker

  8. Litmus paper/ solution (red & blue)

  9. Thistle funnel

  10. Glass rods

  11. Zinc granules

  12. Freshly made lime water

  13. Dilute HCl

  14. Dilute NaOH

  15. Solid sodium carbonate

Let us know more about experiments.


Acids 

  • Acids are compounds which when dissolved in the water yield hydronium ions as the only positively charged ions. 

  • Strength of acid is decided by the basicity of the acid (basicity is the number of hydrogen ions present in the solution when acid is dissolved in water).

  • Eg. Nitric acid gives hydrogen ion and nitric ion and hydrogen ion reacts with water ion which gives hydronium ion.


An Experiment Of Litmus Test

  1. Take two test tubes and label them as A and B 

  2. Take 10 ml of blue litmus in test tube A and 10 ml of red litmus solution in test tube B

  3. Take the dropper filled with nitric acid and add a few drops of it in the test tube A and test tube B

  4. Leave the solution for a few minutes

  5. It is observed that the blue colour of litmus in the test tube A changes its colour to red and is observed that the red colour of litmus solution in test tube B remains the same.

  6. We conclude that acid turns the colour of the litmus solution from blue to red 

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Experiment with Zinc

  1. Take a dry and clean test tube 

  2. Place zinc granules in it

  3. Fill it with liquid HCl submerging zinc granules and tilt it a little bit and fix it with properly in the cork

  4. And place the bunsen burner and lit it 

  5. Close the mouth of the test tube with cork so that no vapour can escape 

  6. Leave the solution for 2-3 minutes it burns with a robust sound releasing a colourless and odourless gas 

  7. And if a burning match stick is brought near the mouth of the test tube it gives a pale blue flame with a pop sound.

(Image to be added soon)

The reaction of the given experiment:

Zn + 2HCl → ZnCl2+H2


Experiment With Solid Sodium Carbonate

  1. Take one gram of solid sodium carbonate with some distilled water in a flat bottomed flask

  2. Take a dry double bore fork and with thistle funnel which has a delivery tube fitted with it

  3. Close the mouth of the flat flask with the dry double bore fork

  4. Add 2 ml of hydrochloric gas

  5. Colourless and odourless gas is liberated which is passed through lime water through the delivery tube

  6. And it turns lime water milky

Na2CO3 + 2HCl →2NaCl+H20(l)+CO2(g)

Experiments on properties of Bases 


Bases

  • Bases are the compounds which react with the acid to give salt and water (neutralisation).

  • Alkalis are bases which can be dissolved in water and yield hydroxyl ions as the only negatively charged ions. eg calcium hydroxide gives calcium ion (positively charged) and hydroxyl ion (negatively charged) thus when alkalis dissolved in water gives hydroxyl ion

  • The strength of the base is given by the acidity of bases.

Note: all alkalis are bases but not all bases are alkalis

  • When sodium hydroxide reacts with hydrochloric acid it gives sodium chloride (salt) and water


An Experiment Of Litmus Test 

  1. Take two test tubes and label them as A and B

  2. Fill test tube A with blue litmus solution and fill test tube A with red litmus solution (each 10 ml).

  3. Use the dropper to add a few drops of calcium hydroxide in the solution in the test tube 

  4. Leave the solution for a few minutes

  5. Observation:The red litmus solution in test tube A turns blue and the blue litmus solution in test tube B doesn't change its colour.

  6. Interference: we conclude that calcium hydroxide is basic in nature and bases turn from red litmus solution to blue litmus solution.


Experiment with Zinc

  1. Take a dry and clean test tube 

  2. Place zinc granules in it

  3. Fill it with liquid NaOH submerging zinc granules and tilt it a little bit and fix it with properly in the cork

  4. And place the bunsen burner and lit it 

  5. Close the mouth of the test tube with cork so that no vapour can escape 

  6. Leave the solution for 2-3 minutes it burns with a robust sound releasing a colourless and odourless gas 

  7. And if a burning match stick is brought near the mouth of the test tube it gives a pale blue flame with a pop sound.

The reaction of the given experiment:

2NaOH+Zn→Na2ZnO2+H2

(Image to be added soon)


Experiment With Solid Sodium Carbonate

  1. Take one gram of Na2CO3 with some distilled water in a flat bottomed flask

  2. Take a dry double bore fork and with thistle funnel which has a delivery tube fitted with it

  3. Add dilute NaOH.

  4. No reaction will take place.

Conclusions of Experiments

Acid

Base

HCl acid turns blue litmus red but does not affect red litmus

NaOH turns red litmus blue but does not affect blue litmus

Acids react with zinc and liberate hydrogen gas and zinc chloride

Bases react with zinc and liberate hydrogen gas and sodium zincate

Acids react with sodium carbonate and release carbon dioxide.

Base does not react with sodium carbonate

FAQ (Frequently Asked Questions)

1. What Precautions Should Be Taken While Performing Experiments Of Properties Of Acids And Bases?

Following precautions should be taken while performing these experiments

  • HCl and NaOH should be handled with care as both are corrosive.

  • Addition of HCl and Na2CO3 should be done in airtight apparatus.

  • Observation of milkiness should be noted as quickly as possible.

  • Clean Zinc metal should be used, otherwise, the reaction will take a longer time to show the results.

  • Small quantities of chemicals should be used.

  • Do not heat Zinc and NaOH solution to boiling point.

  • Test tubes and droppers should not be interchanged while testing with indicators, alkalis, acids.

  • While carrying out a combustion test with H2 proper care should be taken