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प्रश्न
State one use of diamond which depends on its 'extraordinary brilliance' and one use of graphite which depends on its being 'black and quite soft'.
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उत्तर
1. Diamonds are used in making jewellery because of their extraordinary shine and texture.
2.Graphite is used in making pencil leads (black core of pencils) because of its black colour and softness.
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संबंधित प्रश्न
Write the number of covalent bonds in the molecule of butane, C4H10.
What type of bonds are present in Cl2 molecule? Draw their electron-dot structures.
Give one example of a molecule containing a single covalent bond.
Fill in the blank in the following sentence:
The number of single covalent bonds in C2H2 molecule are ...........
State one test by which sodium chloride can be distinguished from sugar.
What is graphite?
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 carbon atoms joined in a spherical molecule of buckminsterfullerene is:
(a) fifty
(b) sixty
(c) seventy
(d) ninety
For each compound mentioned above give the formulae of ions formed in aqueous solution.
Draw all possile structural formulae of compound from their molecular formula given below.
C3H4
Write answer as directed.
What causes the existance of very large number of carbon compound ?
Explain the following briefly.
Pure water does not conduct electricity, but on adding sodium chloride to it, it starts conducting electricity.
Draw the electron dot diagram and structure of nitrogen molecule.
What do you understand by dipole (polar) molecule?
Name two compounds that are covalent when taken pure but produce ions when dissolved in water.
Answer the following question.
What is methane? Draw its electron dot structure. Name the type of bonds formed in this compound. Why are such compounds:
(i) poor conductors of electricity? and
(ii) have low melting and boiling points? What happens when this compound burns in oxygen?
Complete the following activity.
Write the names of the hydrocarbons for the following structural formula.
(isobutylene, cyclohexane, propene, cyclohexene, cyclopentane, benzene, propyne, isobutane, propane)
| \[\begin{array}{cc} \phantom{..}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\ \phantom{..}|\phantom{....}|\phantom{....}|\\ \ce{H - C - C- C- H}\\ \phantom{.}|\phantom{....}|\phantom{....}|\\ \ce{H - C - H}\\ |\\\ce{H}\end{array}\] |
The table shows the electronic structures of four elements.
| Element | Electronic Structure |
| P | 2, 6 |
| Q | 2, 8, 1 |
| R | 2, 8, 7 |
| S | 2, 8, 8 |
- Identify which element(s) will form covalent bonds with carbon.
- “Carbon reacts with an element in the above table to form several compounds.” Give suitable reason.
In covalent compounds, the bond is formed due to ______ of electrons.
