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Question
An organic compound A (molecular formula C2H4O2) reacts with Na metal to form a compound B and evolves a gas which burns with a pop sound. Compound A on treatment with an alcohol C in the presence of a little of concentrated sulphuric acid forms a sweet-smelling compound D (molecular formula C3H6O2). Compound D on treatment with NaOH solution gives back B and C. Identify A, B, C and
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Solution
The organic compound, A, with the molecular formula C2H4O2 is ethanoic acid (CH3COOH), as it evolves hydrogen with a pop sound on reacting with sodium.
When ethanoic acid reacts with sodium, a compound B called the sodium ethanoate (CH3COONa) is formed.
The alcohol, C, is methanol (CH3OH) which is treated with ethanoic acid in the presence of concentrated sulphuric acid to form a compound D.
The sweet-smelling compound D is methyl ethanoate (CH3COOCH3).
The chemical equation for the above stated reaction is as follows:
CH3OH + CH3COOH → CH3COOCH3 + H2O
When ethanoic acid reacts with alcohol in the presence of concentrated sulphuric acid, a sweet-smelling cmpound, ester is formed. Methyl ethanoate is a carboxylate ester, which on reaction with sodium hydroxide gives back methanol and Sodium ethanoate.
The chemical equation is as follows:
CH3COOCH3 + NaOH → CH3COONa + CH3OH
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RELATED QUESTIONS
In an experiment to study the properties of ethanoic acid, a student takes about 3 mL of ethanoic acid in a dry test tube. He adds an equal amount of distilled water to it and shakes the test tube well. After some time he is likely to observe that
(A) a colloid is formed in the test tube.
(B) the ethanoic acid dissolves readily in water.
(C) the solution becomes light orange.
(D) water floats over the surface of ethanoic acid.
For preparing soap in the laboratory we require an oil and a base. Which of the following combinations of an oil and a base would be best suited for the preparation of soap?
(a) Castor oil and calcium hydroxide
(b) Turpentine oil and sodium hydroxide
(c) Castor oil and sodium hydroxide
(d) Mustard oil and calcium hydroxide
Consider the following comments about saponification reactions:
I. Heat is evolved in these reactions.
II. For quick precipitation of soap, sodium chloride is added to the reaction mixtures.
III. Saponification reactions are a special kind of neutralisation reactions.
IV. Soaps are basic salts of long-chain fatty acids.
The correct comments are
(a) I, II and III
(b) II, III and IV
(c) I, II and IV
(d) Only I and IV
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
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(A) a clear transparent colourless solution
(B) a clear transparent pink solution
(C) a precipitate settling at the bottom of the test tube
(D) a layer of water the layer of acetic acid
When you add about 2 ml of acetic acid to a test tube containing an equal amount of distilled water and leave the test tube to settle after shaking its contents, what will you observe in the test tube after about 5 minutes?
(A) A white precipitate settling at its bottom
(B) A clear colourless solution
(C) A layer of water over the layer of acetic acid
(D) A layer of acetic acid over the layer of water
Give the common name and IUPAC name of C2H5OH.
What is the common name of methanol?
What type of compound is formed when a carboxylic acid reacts with an alcohol in the presence of conc. H2SO4?
What will you observe when dilute ethanoic acid and dilute hydrochloric acid are put on universal indicator paper, one by one? What does it show?
The substance which can produce brisk effervescence with baking soda solution is:
(a) ethanol
(b) vegetable oil
(c) vinegar
(d) soap solution(b) hydrocarbon ends directed towards the centre and ionic ends directed outwards
In a soap micelle, the soap molecules are arranged radially with the hydrocarbon ends, i.e. hydrophobic, directed towards the centre; and, ionic ends, i.e. hydrophilic, directed outwards.
Consider the following organic compounds:
HCHO, C2H5OH, C2H6, CH3COOH, C2H5CI
Choose two compounds which can react in the presence of conc. H2SO4 to form an ester. Give the name and formula of the ester formed.
Name the product formed and give an appropriate chemical equation for the following:
Ethanol oxidised by acidified potassium dichromate.
Explain the following term with example.
Reduction
State how the following conversion can be carried out:
Ethyl chloride to Ethene.
State are relevant observations for following reactant:
Addition of ethyl alcohol to acetic acid in presence of conc. H2SO4
Identify the term or substance based on the descriptions given below:
Hydrocarbon containing a triple bond used for welding purposes
Rewrite the following statement by selecting the correct option.
The formula of ethanoic acid is _____________.
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.
Write the chemical equation for the following:
Esterification Reaction
