Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
(i) Ethanoic acid
(ii) The structural isomers possible for bromopentane. Among them, the structures of three isomers are:
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.
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.
Why is sodium kept immersed in kerosene oil?
You have two solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of this is acidic and which one is basic?
Explain the following.
(a) Why is the tungsten used almost exclusively for filament of electric lamps?
(b) Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
(c) Why is the series arrangement not used for domestic circuits?
(d) How does the resistance of a wire vary with its area of cross-section?
(e) Why are copper and aluminium wires usually employed for electricity transmission?
What is the need for a system of control and coordination in an organism?
Can you suggest some changes in your school which would make it environment-friendly?
What are the components of the transport system in human beings? What are the functions of these components?
Describe the structure and functioning of nephrons.
Name the sodium compound which is used for softening hard water.
How is a voltmeter connected in the circuit to measure the potential difference between two points?
How does chemical coordination take place in animals?