3 mL of ethanol is taken in a test tube and warmed gently in a water bath. A 5 % solution of alkaline potassium permanganate is added first, drop by drop to this solution, then in excess. How is 5 % solution of KMnO 4 prepared? State the role of alkaline potassium permanganate in this reaction. What happens on adding it in excess? Write a chemical equation of this reaction.

To make 5 % of KMnO 4 solution, 5 g of KMnO 4 is to be added in water to make the final volume 100 mL . Alkaline potassium permanganate acts as an oxidising agent which provides a nascent oxygen to the alcohol and turns it into a carboxylic acid. When purple alkaline KMnO 4 is added drop by drop into ethanol, it reacts to give acetic acid and the purple colour of KMnO 4 disappears. When it is added in excess, the entire ethanol has been turned into acid and no more ethanol is left to react with alkaline KMnO 4 and the purple colour persists in the solution. Ethanol on reaction with alkaline KMnO 4 gets oxidised and forms ethanoic acid. Ethanoic acid is also known as acetic acid. The reaction between ethanol and alkaline KMnO 4 is as follows: C 2 H 5 OH ethanol → heat alkaline KMnO 4 CH 3 COOH ethanoic acid

3 mL of ethanol is taken in a test tube and warmed gently in a water bath. A 5 % solution of alkaline potassium permanganate is added first, drop by drop to this solution, then in excess. How is 5 % solution of KMnO 4 prepared? State the role of alkaline potassium permanganate in this reaction. What happens on adding it in excess? Write a chemical equation of this reaction.

To make 5 % of KMnO 4 solution, 5 g of KMnO 4 is to be added in water to make the final volume 100 mL . Alkaline potassium permanganate acts as an oxidising agent which provides a nascent oxygen to the alcohol and turns it into a carboxylic acid. When purple alkaline KMnO 4 is added drop by drop into ethanol, it reacts to give acetic acid and the purple colour of KMnO 4 disappears. When it is added in excess, the entire ethanol has been turned into acid and no more ethanol is left to react with alkaline KMnO 4 and the purple colour persists in the solution. Ethanol on reaction with alkaline KMnO 4 gets oxidised and forms ethanoic acid. Ethanoic acid is also known as acetic acid. The reaction between ethanol and alkaline KMnO 4 is as follows: C 2 H 5 OH ethanol → heat alkaline KMnO 4 CH 3 COOH ethanoic acid

A compound ‘ X ’ on heating with excess conc. sulphuric acid at 443 K gives an unsaturated compound ‘ Y ’. ‘ X ’ also reacts with sodium metal to evolve a colourless gas ‘ Z ’. Identify ‘ X ’, ‘ Y ’ and ‘ Z ’. Write the equation of the chemical reaction of formation of ‘ Y ’ and also write the role of sulphuric acid in the reaction.

Compound X is CH 3 CH 2 OH -ethanol, which on heating with concentrated sulphuric acid at 443 K gives ethene, which is an unsaturated compound. Ethanol reacts with sodium metal to produce sodium ethoxide and hydrogen gas ' Z '. CH 3 CH 2 OH + Na → CH 3 CH 2 ONa + H 2 Chemical reaction of formation of Y is, CH 3 CH 2 OH Ethanol → 443 K Conc . H 2 SO 4 CH 2 = CH 2 Ethene + H 2 O Here, concentrated sulphuric acid acts as a dehydrating agent, it removes water molecule from ethanol.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2018>Q 2

EASY

10th CBSE

IMPORTANT

Earn 100

Why are most carbon compounds poor conductors of electricity?

Important Questions on Carbon and its Compounds

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2018>Q 3

Write the name and structure of a saturated compound in which the carbon atoms are arranged in a ring. Give the number of single bonds present in this compound.

HARD

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2019>Q 4

What is a homologous series of carbon compounds ? Give an example and list its three characteristics.

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2019>Q 5

Write the molecular formula of ethene and draw its electron dot structure.

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2020>Q 6

Incomplete combustion of coal and petroleum:

(A) increases air pollution.

(B) increases efficiency of machines.

(C) reduces global warming.

(D) produce poisonous gases.

The correct option is:

HARD

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2020>Q 8

$3 mL$ of ethanol is taken in a test tube and warmed gently in a water bath. A $5 %$ solution of alkaline potassium permanganate is added first, drop by drop to this solution, then in excess.

How is $5 %$ solution of ${KMnO}_{4}$ prepared?
State the role of alkaline potassium permanganate in this reaction. What happens on adding it in excess?
Write a chemical equation of this reaction.

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2020>Q 9

Name a cyclic unsaturated carbon compound.

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2021 Term I>Q 10

Which one of the following structures correctly depicts the compound

{CaCl}_{2}

?

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 4 - Carbon and its Compounds>CBSE-2022 (Delhi Term II - I)>Q 11

"Carbon prefers to share its valence electrons with other atoms of carbon or with atoms of other elements rather than gaining or losing the valence electrons in order to attain noble gas configuration." Give reasons to justify this statement.

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