List of top Science Questions on Carbon and Its Compound asked in CBSE Class X

A carbon compound 'A' is widely used as a preservative in pickles and has a molecular formula C\(_2\)H\(_4\)O\(_2\). This compound reacts with ethanol to form a sweet smelling compound 'B'.
(i) Identify the compound 'A' and write its structure.
(ii) Write the chemical equation for the reaction of 'A' with ethanol to form compound 'B'. State the role of presence of an acid in the reaction.
(iii) How can we get compound 'A' back from 'B' ?
(iv) How can 'A' be obtained from ethanol ?
(v) Name the gas produced when compound 'A' reacts with washing soda.
A carbon compound 'A' on heating with excess conc. H\(_2\)SO\(_4\) forms a compound 'B', which on addition of one mole of hydrogen gas in the presence of nickel catalyst forms a compound 'C'. 'C'. on combustion in air forms 2 moles of carbon dioxide and 3 moles of water. Identify 'A', 'B' and 'C' and write their structures. Give chemical equations of the reactions involved. Also state the role of concentrated sulphuric acid in the formation of 'B' from 'A'.
What are soaps? Write the structure of a soap molecule. Explain the cleansing action of a soap. Why are soaps not considered suitable for washing clothes in a region where water is hard? How is this problem overcome?
Name an alcohol and a carboxylic acid having two carbon atoms in their structures. Draw their structures and state how this alcohol can be converted into a carboxylic acid. What happens when these two compounds react in the presence of an acid? Write chemical equations for the reactions involved in the two cases mentioned above.
Assertion (A): Xylem tissue moves water and minerals obtained from the soil by the roots.
Reason (R): Xylem tissue is found only in the roots of a plant.
A Hydrocarbon which does not belong to the same homologous series of carbon compounds is:
Why are carbon compounds exceptionally stable?
An organic compound ‘X’ when reacts with sodium liberates hydrogen. The same compound ‘X’ when heated at 443 K in the presence of concentrated sulphuric acid gives an unsaturated hydrocarbon.
(i) Identify ‘X’.