Explain the formation of scum when hard | Class 10 Science Chapter Carbon and Its Compound, Carbon and Its Compound NCERT Solutions

What are oxidising agents?

What would be the electron dot structure of carbon dioxide which has the formula CO₂?

How would you name the following compounds?

   (i)    CH₃  -- CH₂  -- Br

  (ii)

(iii) 

Butanone is a four-carbon compound with the functional group

(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.

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

What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? (Hint – The eight atoms of sulphur are joined together in the form of a ring.)

Which of the following hydrocarbons undergo addition reactions: C₂H₆, C₃H₈, C₃H₆, C₂H₂ and CH₄.

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that

(a) the food is not cooked completely.
(b) the fuel is not burning completely.
(c) the fuel is wet.
(d) the fuel is burning completely.

A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?

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

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

Outline a project which aims to find the dominant coat colour in dogs.

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?

How is the sex of the child determined in human beings?

(a)  What property do all elements in the same column of the Periodic Table as boron have in common?
(b)  What property do all elements in the same column of the Periodic Table as fluorine have in common?

Calculate the number of electrons constituting one coulomb of charge.

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?

Why is variation beneficial to the species but not necessarily for the individual?

Give an example of a metal which

  (i) is a liquid at room temperature.
  (ii) can be easily cut with a knife.
  (iii) is the best conductor of heat.
  (iv) is a poor conductor of heat.

Write equations for the reactions of

   (i) iron with steam
   (ii) calcium and potassium with water.

Give any two ways in which non-biodegradable substances would affect the environment.

Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?

On the basis of the issues raised in this chapter, what changes would you incorporate in your lifestyle in a move towards a sustainable use of our resources?

Where do plants get each of the raw materials required for photosynthesis?

How can you as an individual contribute or make a difference to the management of (a) forests and wildlife, (b) water resources and (c) coal and petroleum?

Can you suggest some changes in your school which would make it environment-friendly?

Answer the following :
(a) Which hormone is responsible for the changes noticed in females at puberty?
(b) Dwarfism results due to deficiency of which hormone?
(c) Blood sugar level rises due to deficiency of which hormone?
(d) Iodine is necessary for the synthesis of which hormone?

What changes are observed in the uterus subsequent to implantation of young embryo?

If you could use any source of energy for heating your food, which one would you use and why?

A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as

(a) TTWW
(b) TTww
(c) TtWW
(d) TtWw