Explain the nature of the covalent bond using the bond formation in CH3Cl.
Carbon can neither lose four of its electrons nor gain four electrons as both the processes require an extra amount of energy and that would make the carbon atom unstable. Therefore, it completes its octet by sharing its four valence electrons with other carbon atoms or with atoms of other elements. The bonds that are formed by sharing electrons are known as covalent bonds. In covalent bonding, both the atoms share the valence electrons.
Carbon requires 4 electrons to complete its octet, while each hydrogen atom requires one electron to complete its duplet. Also, chlorine requires an electron to complete the octet. Therefore, all of these share the electrons and as a result, carbon forms 3 bonds with hydrogen and one with chlorine.
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?
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 can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?
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.
How will an organism be benefited if it reproduces through spores?
Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
List five things you have done over the last one week to —
(a) conserve our natural resources.
(b) increase the pressure on our natural resources.
How are the modes for reproduction different in unicellular and multicellular organisms?
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.
Find the focal length of a convex mirror whose radius of curvature is 32 cm.
What happens to the image distance in the eye when we increase the distance of an object from the eye?
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
What is the role of decomposers in the ecosystem?
What precaution should be taken to avoid the overloading of domestic electric circuits?