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प्रश्न
Explain why, graphite can be used as a lubricant but diamond cannot.
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उत्तर
Because of its softness and non-volatile nature, graphite is used as a lubricant in the fast moving parts of a machinery. It is used for lubricating the parts of machinery which operate at high temperatures. Diamond, on the other hand, is an extremely hard substance; therefore, it cannot be used as a lubricant.
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संबंधित प्रश्न
Give one example of a molecule containing a double covalent bond
What type of bond exist in CCl4?
Why is graphite used for making dry cell electrodes but diamond is not?
will CS2 conduct electricity or not?
give reason for your choice.
Out of KCl, HCl, CCl4 and NaCl, the compounds which are not ionic are:
(a) KCl and HCl
(b) HCl and CCl4
(c) CCl4 and NaCl
(d) KCl and CCl4
Two non-metals combine with each other by the sharing of electrons to form a compound X.
(a) What type of chemical bond is present in X?
(b) State whether X will have a high melting point or low melting point.
(c) Will it be a good conductor of electricity or not?
(d) Will it dissolve in an organic solvent or not?
The number of isomers formed by the hydrocarbon with molecular formula C5H12 is:
(a) 2
(b) 5
(c) 3
(d) 4
An element E exists in three allotropic forms A, B and C. In allotrope A, the atoms of element E are joined to form spherical molecules. In allotrope B, each atom of element E is surrounded by three other E atoms to form a sheet like structure. In allotrope C, each atom of element E is surrounded by four other E atoms to form a rigid structure.
(a) Name the element E.
(b) What is allotrope A.
(c) What is allotrope B?
(d) What is allotrope C?
(e) Which allotrope is used in making jewellery?
(f) Which allotrope is used in making anode of a dry cell?
Explain the following:
polar covalent compounds electricity.
Explain the following:
Polar covalent compounds are good conductors of electricity.
Name a neutral covalent molecule which contains one lone pair of electrons.
The electronic configuration of N2 is 2, 5. How many electrons in the outer shell of a N atom are not involved in the formation of a nitrogen molecule?
An element L consists of molecules.
Why L is heated with iron metal, it forms a compound FeL. What chemical term would you use to describe the change undergone by L?
Elements Q and S react together to form an ionic compound. Under normal conditions, which physical state will the compound QS exist in?
Write an Explanation.
Alkyne
Complete the following activity.
Write the names of the hydrocarbons for the following structural formula.
(isobutylene, cyclohexane, propene, cyclohexene, cyclopentane, benzene, propyne, isobutane, propane)
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The bond which is formed by the mutual sharing of electrons is called ______ bond.
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Explain dipole (polar) molecule by taking hydrogen chloride as an example.
