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प्रश्न
‘A’ is an element having four electrons in its outermost orbit. An allotropes ‘B’ of this element is used as a dry lubricant in machinery and in pencil leads. So:
i. Write the name of element ‘A’ and its allotropes.
ii. State whether ‘B’ is a good conductor or non-conductor of electricity?
उत्तर
(i) The name of the element 'A' is carbon. The name of its allotrope is graphite.
(ii) The allotrope 'B', i.e. graphite, is a good conductor of electricity.
संबंधित प्रश्न
Define Unsaturated hydrocarbon.
Explain in brief two main reasons for carbon forming a large number of compounds.
Draw the electron dot structures for propanone.
Draw the electron dot structures for F2.
Why are certain compounds called hydrocarbons? Write the general formula for homologous series of alkanes, alkenes and alkynes and also draw the structure of the first member of each series. Write the name of the reaction that converts alkenes into alkanes and also write a chemical equation to show the necessary conditions for the reaction to occur.
A compound 'X' on heating with excess conc. sulphuric acid at 443 K gives an unsaturated compound 'Y'. 'X' also reacts with sodium metal to evolve a colourless gas 'Z'. Identify 'X', 'Y' and 'Z'. Write the equation of the chemical reaction of formation of 'Y' and also write the role of sulphuric acid in the reaction.
Write the electron-dot structures for ethyne.
Fill in the following blank with suitable word:
The form of carbon which is used as a lubricant at high temperature is .........
Giving their structures, state the number of single bonds, double bonds and triple bonds (if any) in the following compounds:
ethene
Out of the following pairs of compounds, the unsaturated compounds are:
(a) C2H6 and C4H6
(b) C6H12 and C5H12
(c) C4H6 and C6H12
(d) C2H6 and C4H10
A cyclic hydrocarbon having carbon-carbon single bonds as well as carbon-carbon double bonds in its molecule is:
(a) C6H12
(b) C6H14
(c) C6H6
(d) C6H10
An unsaturated hydrocarbon having a triple covalent bond has 50 hydrogen atoms in its molecule. The number of carbon atoms in its molecule will be:
(a) 24
(b) 25
(c) 26
(d) 28
Name two catalysts which can be used in the hydrogenation of unsaturated compounds.
Which of the following hydrocarbons can decolourise bromine water and which cannot? Why?
C6H12, C6H14, C6H10
Differentiate between alkanes and alkenes. Name and draw the structure of one member of each.
Fill in the blanks and rewrite the completed statements:
The organic compounds having double or triple bond in them are termed as _________________ _________________.
How many double bonds are there in a saturated hydrocarbon?
Which of the following is the correct representation of electron dot structure of nitrogen?
Structural formula of ethyne is
Identify the unsaturated compounds from the following
- Propane
- Propene
- Propyne
- Chloropropane
What is the role of metal or reagents written on arrows in the given chemical reactions?
- \[\begin{array}{cc}
\ce{CH3}\phantom{.....}\ce{CH3}\phantom{.........}\ce{CH3}\phantom{..}\ce{CH3}\phantom{..........}\\
\phantom{...}\backslash\phantom{......}/\phantom{................}|\phantom{.....}|\phantom{............}\\
\ce{C} = \ce{C} + \ce{H2} \overset{\ce{Ni}}{\rightarrow} \ce{CH3 - C - C - CH3}\\
\phantom{.}/\phantom{........}\backslash\phantom{..............}|\phantom{....}|\phantom{.........}\\
\ce{CH3}\phantom{....}\ce{CH3}\phantom{............}\ce{H}\phantom{...}\ce{H}\phantom{........}
\end{array}\] - \[\ce{CH3COOH + CH3CH2OH \overset{\ce{Conc. H2SO4}}{\rightarrow}CH3COOC2H5 + H2O}\]
- \[\ce{CH3CH2OH}\ce{->[Alk.KMnO4][Heat]CH3COOH}\]
- What are hydrocarbons? Give examples.
- Give the structural differences between saturated and unsaturated hydrocarbons with two examples each.
- What is a functional group? Give examples of four different functional groups.
Name the reaction which is commonly used in the conversion of vegetable oils to fats. Explain the reaction involved in detail.
Write the name of the following compound
\[\begin{array}{cc}
\phantom{}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\phantom{.....}\\
\phantom{}|\phantom{....}|\phantom{....}|\phantom{.....}\\
\ce{H} - \ce{C} - \ce{C} - \ce{C} ≡ \ce{C} - \ce{H}\\
\phantom{}|\phantom{....}|\phantom{..........}\\
\phantom{}\ce{H}\phantom{...}\ce{H}\phantom{..........}\\
\end{array}\]
Draw the electron dot structure for ethyne.
