Chemistry
Give reasons:
(a) Ethyne is more reactive than ethene.
(b) Ethene is more reactive than ethane.
(c) Hydrocarbons are excellent fuels.
Answer
(a) The two carbon atoms of ethyne form a triple covalent bond whereas that of ethene form a double covalent bond. Hence, there are more electrons available in case of ethyne making it more reactive than ethene.
(b) Ethene is an unsaturated hydrocarbon having two carbon atoms forming a double covalent bond as their valencies are not fully satisfied by hydrogen atoms whereas ethane is a saturated hydrocarbon as all the four valencies of its two carbon atoms are satisfied by the hydrogen atoms. The availability of electrons in the double bond in case of ethene makes it more reactive than ethane which has does not have electrons available in the single covalent bond.
(c) Hydrocarbons have high calorific value. They are easily combustible and the reaction is exothermic releasing heat energy. Hence, they are excellent fuels.
Related Questions
Substitution reactions are characteristic reactions of …………… (alkynes/alkenes/alkanes).
(a) Write an equation for the laboratory preparation of
(i) An unsaturated hydrocarbon from calcium carbide.
(ii) An alcohol from ethyl bromide.
(b) What would you see, when ethyne is bubbled through a solution of bromine in carbon tetrachloride?
(c) Name the addition product formed between ethene and water.
(a) Write balanced equations:
(i) when butane is burnt in oxygen
(ii) for preparation of ethylene from ethyl alcohol.
(b) (i) Convert ethane to acetic acid
(ii) Convert ethyne to ethane.
(a) Write the equation for the preparation of carbon tetrachloride from methane.
(b) Draw the structural formula of ethyne.
(c) How is the structure of alkynes different from that of alkenes?