What is an homologous series? Explain with an example.
A homologous series is a series of carbon compounds that have different numbers of carbon atoms but contain the same functional group.
For example, methane, ethane, propane, butane, etc. are all part of the alkane homologous series. The general formula of this series is CnH2n+2.
Methane - CH4
Ethane - CH3CH3
Propane - CH3CH2CH3
Butane - CH3CH2CH2CH3
In a homologous series of alkane there is a difference of one carbon and 2 hydrogen unit between each successive member.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
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.
Why are carbon and its compounds used as fuels for most applications?
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.
Calculate the number of electrons constituting one coulomb of charge.
Translate the following statements into chemical equations and then balance them.
(a) Hydrogen gas combines with nitrogen to form ammonia.
(b) Hydrogen sulphide gas burns in air to give water and sulpur dioxide.
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
The phenomenon of electromagnetic induction is
(a) the process of charging a body.
(b) the process of generating magnetic field due to a current passing through a coil.
(c) producing induced current in a coil due to relative motion between a magnet and the coil.
(d) the process of rotating a coil of an electric motor.
Describe the structure and functioning of nephrons.
Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?
What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer.
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
(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?
How is the sex of the child determined in human beings?
How does a solenoid behave like a magnet? Can you determine the north and south poles of a current–carrying solenoid with the help of a bar magnet? Explain.
Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 108 m s–1.