Advertisements
Advertisements
Question
Explain why, diamond is hard while graphite is soft (though both are made of carbon atoms).
Advertisements
Solution
Even if diamond and graphite are made up of carbon, the former is extremely hard while the latter is soft. Diamond is hard because of the strong covalent bond between its carbon atoms forming a regular tetrahedron which is hard to break. Graphite, on the other hand, consists of flat hexagonal ring forming layers of carbon atoms. The various layers of the carbon atoms are far apart from each other; hence, the covalent bond cannot exist. The layers are held together by weak van der Waals forces, thereby allowing them to slide over each other. Due to this layered structure, graphite is softer than diamond.
APPEARS IN
RELATED QUESTIONS
State the reason why carbon can neither form C4+ cations nor C4− anions but forms covalent compounds.
Butanone is a four-carbon compound with the functional group:
What is a covalent bond?
What type of chemical bonds are formed by carbon? Why?
Why is graphite used for making dry cell electrodes but diamond is not?
Describe the structure of graphite with the help of a labelled diagram.
A covalent molecule having a double bond between its atoms is:
(a) Hydrogen
(b) Oxygen
(c) water
(d) ammonia
The number of carbon atoms joined in a spherical molecule of buckminsterfullerene is:
(a) fifty
(b) sixty
(c) seventy
(d) ninety
What is the difference between ionic compounds and polar covalent compounds?
State the type of bonding in the following molecule.
Methane
Complete the following:
When the nuclei of two different reacting atoms are of ______ mass, then a bond so formed is called ______ covalent bond. (equal, unequal, polar, non-polar)
Explain the following term with example.
Unsaturated hydrocarbon
Observe the straight chain hydrocarbons given below and answer the following
questions :
i) Which of the straight chain compounds from A and B is saturated and unsaturated straight chains?
ii) Name these straight chains.
iii) Write their chemical formulae and number of – CH2 - units.
The molecule which contains a triple covalent bond is ______.
Define a covalent bond.
Write an Explanation.
Alkene
When ethyl alcohol and acetic acid are mixed, the resulting ester has a chemical formula ______.
Cation is formed when ______.
Mineral acids are stronger acids than carboxylic acids because
- mineral acids are completely ionised
- carboxylic acids are completely ionised
- mineral acids are partially ionised
- carboxylic acids are partially ionised
Show the covalent bond formation in nitrogen molecule.
