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प्रश्न
A student adds a few drops of ethanoic acid to test tubes X, Y and Z containing aqueous solutions of sodium chloride, sodium hydroxide and sodium carbonate, respectively. If he now brings a burning splinter near the mouth of the test tubes immediately after adding ethanoic acid in each one of them, in which of the test tube or test tubes the flame will be extinguished?
(A) X and Y
(B) Y and Z
(C) X and Z
(D) only Z
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उत्तर
The chemical reactions in test tubes X, Y and Z can be written as:-
Test tube X:-
CH3COOH + NaCl →No reaction
Test tube Y:-
CH3COOH + NaOH →CH3COONa + H2O
Test tube Z:-
2 CH3COOH + Na2CO3 →2 CH3COONa + CO2 + H2O
Thus, the flame will be extinguished when test tube Z is brought near a burning splinter due to evolution of carbon dioxide gas, which does not support combustion.
Hence, the correct option is D.
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संबंधित प्रश्न
A student takes about 6 ml of distilled water in each of the four test tubes P, Q, R and S. He then dissolves an equal amount of four different salts namely, sodium chloride in 'P', potassium chloride in 'Q', calcium chloride in 'R' and magnesium chloride in 'S'. Next, he then adds 10 drops of soap solution to each test tube and shakes its contents. The test tubes in which scum (insoluble substance) is formed with soap are:
(A) P and Q
(B) Q and R
(C) R and S
(D) Q and S
Choose the correct alternative and rewrite the following:
Acetic acid ..................
What do you notice when acetic acid reacts with alkalies?
Which of the following observations is true about dilute solution of acetic acid?
(A) It smells like vinegar and turns red litmus blue
(B) It smells like onion and turns blue litmus red
(C) It smells like orange and turns red litmus blue
(D) It smells like vinegar and turns blue litmus red
A student adds 4 mL of acetic acid to a test tube containing 4 mL of distilled water. He then shakes the test tube and leaves it to settle. After about 10 minutes he observes:
(A) a layer of water over the layer of acetic acid
(B) a layer of acetic acid over the layer of water
(C) a precipitate settling at the bottom of the test tube
(D) a clear colourless solution
What is thr boilng point of acetic acid?
Why is pure acetic acid also known as glacial acetic acid?
Explain the following reaction with an example.
Esterification
Explain the following reaction with an example.
Saponification
Shristi heated Ethanol with a compound A in presence of a few drops of concentrated sulphuric acid and observed a sweet smelling compound B is formed. When B is treated with sodium hydroxide it gives back Ethanol and a compound C.
- Identify A and C
- Give one use each of compounds A and B.
- Write the chemical reactions involved and name the reactions.
