Class 10 Science - Chapter Carbon and Its Compound NCERT Solutions | Why are carbon and its compounds used as

Draw the structure for the following compounds.                

       (i)    Ethanoic acid             (ii)   Bromopentane*
       (iii)  Butanone                   (iv)   Hexanal.

*Are structural isomers possible for bromopentane?

What is an homologous series? Explain with an example.

How would you name the following compounds?

   (i)    CH₃  -- CH₂  -- Br

  (ii)

(iii) 

What will be the formula and electron dot structure of cyclopentane?

Explain the nature of the covalent bond using the bond formation in CH₃Cl.

How many structural isomers can you draw for pentane?

Explain the mechanism of the cleaning action of soaps.

What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?

Explain the formation of scum when hard water is treated with soap.

How would you distinguish experimentally between an alcohol and a carboxylic acid?

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

What is a good source of energy?

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

What is the importance of DNA copying in reproduction?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Why should a magnesium ribbon be cleared before burning in air?

Define the principal focus of a concave mirror.

 Balance the following chemical equations.

(a) HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + H₂O
(b) NaOH + H₂SO₄ → Na₂SO₄ + H₂O
(c) NaCl + AgNO₃ → AgCl + NaNO₃
(d) BaCl₂ + H₂SO₄ → BaSO₄ + HCl

A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located?

Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.

(a) What will be the action of gas on

      (i) dry litmus paper?
      (ii) moist litmus paper?

(b) Write a balanced chemical equation for the reaction taking place.

State two ways to prevent the rusting of iron.

Redraw the circuit of Question 1, putting in an ammeter to measure the current through the resistors and a voltmeter to measure the potential difference across the 12 Ω resistor. What would be the readings in the ammeter and the voltmeter?

An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.

How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?

A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R′, then the ratio R/R′ is –

(a) 1/25        (b) 1/5        (c) 5        (d) 25

What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series?

Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of (i) 9 Ω, (ii) 4 Ω.