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प्रश्न
You have four test tubes, A, B, C and D containing sodium carbonate, sodium chloride, lime water and blue litmus solutions respectively. Out of these the material of which test tube/ test tubes would be suitable for the correct test of acetic/ethanoic acid?
(a) only A
(b) A and B
(c) B and C
(d) A and D
उत्तर
Ethanoic (acetic) acid is an acid, and it will change blue litmus solution to red.
The chemical reaction between ethanoic (acetic) acid and sodium carbonate is:
2 CH3COOH + Na2CO3 → 2 CH3COONa + CO2 + H2O
On passing CO2 gas through lime water, the lime water turn milky. The milky apprearance of lime water is due to the formation of solid calcium carbonate (CaCO3).
Reaction:
Ca(OH)2 + CO2 → CaCO3 + H2O
Therefore, out of four test tubes A, B, C and D, only A and D test tubes would be suitable for the correct test of acetic/ethanoic acid.
Acetic acid also reacts with lime water to give calcium acetate (CH3COO)2Ca) as a product. But here it is not consider as correct test of acetic/ethanoic acid.
Reaction:
2 CH3COOH + Ca(OH)2 → (CH3COO)2Ca + 2 H2O
Hence, the correct answer is option (d).
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संबंधित प्रश्न
What do you observe when you drop a few drops of acetic acid to test tubes containing
(a) phenolphthalein
(b) distilled water
(c) universal indicator
(d) sodium hydrogen carbonate powder
In order to study saponification reaction, we first prepare 20% solution of sodium hydroxide. If we record the temperature of this solution just after adding sodium hydroxide flakes to water and also test its nature using litmus, it may be concluded that the process of making this solution is
(A) exothermic and the solution is alkaline
(B) endothermic and the solution is alkaline
(C) endothermic and the solution is acidic
(D) exothermic and the solution is acidic
Describe one reaction of a carboxylic acid.
Give any two uses of ethanoic acid.
Why is Soda lime used not only NaOH?
With a labelled diagram describe in brief an activity to show the formation of ester.
Write the answers to the questions by observing the following figure.
- Write the chemical reaction shown in the figure above in the form of a balanced equation.
- Write the name of the gas coming out of the large test tube in the above chemical reaction.
- Why do small bubbles appear in the small test tube?
- What is the change in colour of lime water?
Ester is formed by the reaction between ______.
Write the chemical equation for the following:
Saponification Reaction
A spatula full of sodium carbonate is taken in a test tube and 2 mL of dilute ethanoic acid is added to it.
Write a chemical equation for the reaction.
