organic chemistry Flashcards
Define the term ‘catenation’
Catenation is defined as the tendency of an element to form chains of identical atoms.
(ii) Which one of the elements – Li, Be, B, C, O, F, Ne shows the property of catenation.
(ii) C.
(i) State the term for:- Compounds having the same general formula and similar chemical properties.
(i) Homologus series.
(ii) Name (a) The compound with – OH and with – COOH as the part of its structure.
(b) Homologue of homologus series with general formula CnH2n from the compounds given: Ethane, Ethene, Ethanoic acid, Ethyne, Ethanol.
ii) (a) Ethanol and Ethanoic acid.
(b) Ethene [a member of Alkene]
(i) State the structural formula of ethane.
(ii) Draw the structural formula of the two isomers of Butane. Give the correct IUPAC name of each.
(iii) From the following list, write down the appropriate words to fill in the blanks (a) to (e) below: -
Addition, carbohydrates, CnH2n-2, CnH2n, CnH2n+2, electrochemical, homologus, hydrocarbons, saturated, substitution, unsaturated.
The alkane from an (a) ________ series with the general formula (b) __________. The alkanes are (c) __________ (d) __________ which generally undergo (e) ___________ reaction.
iii) (a) Homologus
(b) CnH2n+2
(c) Sturated
(d) Hydrocarbon
(e) Substitution.
(i) For each of the compounds (a) Ethane, (b) Vinegar [acetic acid] and (iii) Marsh gas [methane], draw the relevant structural formula. What word is used to describe the above three compounds taken together?
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(ii) Draw the structural formula of ethane. What is the feature of the ethane structure which allows ethane to react with chlorine in the way it does.
(i) What is the special feature of the structure of : (a) C2H4 (b) C2H2.
(i) Both are unsaturated hydrocarbons. C2H4 (Ethene) contain carbon to carbon double bond and C2H2 (Ethyne) contain carbon to carbon triple bond.
(ii) What type of reaction is common to both these compounds?
i) Both type of compounds undergo addition reactions.
(iii) Give the name and structural formula of (a) a saturated hydrocarbon, (b) an unsaturated hydrocarbon with a double bond.
) Copy and complete the following sentence: A saturated hydrocarbon will undergo _________ reactions whereas the typical reaction of an unsaturated hydrocarbon is _________.
iv) substitution, addition reaction.
v) State the term defined by the following :- Compounds containing carbon and hydrogen only.
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(v) Hydrocarbons.
(vi) State the general formula for a saturated hydrocarbon and give one example and structural formula of the same.
General formula : CnH2n+2.
Example : C2H6.
) Draw the structural formula of ethyne. How does the structure of alkynes differ from that of alkenes.
H – C ≡ C – H
Alkyne possess a triple bond between carbon to carbon atoms whereas alkenes possess a double bond between carbon to carbon atoms.
iii) Fill in the blanks with the correct words : – Alkanes are the (a) _______ [analogous / homologous] series of (b) _______ [saturated / unsaturated] hydrocarbons. They differ from alkanes due to the presence of (c) _________ [double / single] bonds. Alkenes mainly undergo (d) ________ [addition / substiution] reactions.
(viii) (a) Homologous (b) Unsaturated (c) Double (d) Addition.
Which compound is heated with soda lime to obtain C2H6 in the laboratory . Write the equation for the same.
(i) Sodium propanoate [sodium propionate]
CaO CH3 – CH2 – COONa + NaOH → C2H6 + Na2CO3
Δ Ethane
Write the equation for the preparation of CH4 from anhydrous sodium ethanoate [sodium acetate].
(ii) CaO
CH3 – COONa + NaOH → CH4 + Na2CO3
Δ Methane
) What type of reaction has taken place between ethane and chlorine.
Write the equation of the complete combustion of ethane.
ii) 2C2H6 + 7O2 → 4CO2 + 6H2O + Heat.
What is the type of reaction taking place between ethane and chlorine to form mono-chloro-ethane.
Substitution reaction.
Write the equation for the preparation of carbon tetrachloride from methane.
uv[light]
CH4 + Cl2 → CH3Cl + HCl
or Δ
Write a balanced equation for the reaction of ethane and oxygen in presence of molybdenum oxide.
MoO
(v) C2H6 + O2 → CH3CHO + H2O
[350-500ºC]
Name a solid used instead of conc. H2SO4to prepare ethylene by the dehydration of ethanol
(i) Alumina at 350ºC.
Conc. H2SO4
Write the equation for the preparation of ethylene from ethyl alcohol.
Or,
Write the equation for the reaction of heating ethanol at 170ºC in the presence of conc. H2SO4.
(ii) C2H5OH → C2H4 + H2O
160º – 170ºC
Write a balanced equation for the reaction between ethene and hydrogen.
State what do you observe when ethene is bubbled through a solution of bromine in tetrachloromethane (carbon tetrachloride).
Colour of bromine disappears.
(iii) The reaction between ethene and chlorine forms only one product. Name the type of this equation.
Addition reaction.
Ethylene forms an addition product with Cl2. Name the product and give its structural formula.
Write down the equation for the preparation of ethyne from calcium carbide.
`CaC2 + 2H2O → Ca(OH)2 + C2H2.
Burning of acetylene (ethyne) in oxygen produces a very hot flame. What is this hot flame used for.
It is used for welding and cutting metals.
State one use of acetylene.
Welding and cutting metals.
What is the type of reaction between ethene and chlorine.
Addition reaction.
What feature of the ethene structure makes such a reaction possible.
Presence of double covalent bond.
Name the product of the reaction between ethene and chlorine.
1,2-dichloro ethane.
What is the special feature of the structure of ethyne.
Presence of triple covalent bond.
The conversion of ethanol to ethene is an example of ______ (dehydration / dehydrogenation).
Dehydration
Converting ethanol to ethene requires the use of ________ (concentrated hydrochloric acid / concentrated nitric acid / concentrated sulphuric acid).
Concentrated sulphuric acid
The conversion of ethene to ethane is an example of _______ (hydration / hydrogenation)
Hydrogenation
The catalyst used in the conversion of ethene to ethane is commonly ________ (iron / nickel / cobalt).
Nickel
From the list given : - ethanol, ethane, methanol, methane, ethyne and ethene. Name a compound : -
(a) Formed by the dehydration of ethanol by concentrated sulphuric acid.
(a) Ethene or Ethylene
b) Which will give a red precipitate with ammoniacal cuprous chloride solution.
(b) Ethyne or Acetylene
(c) Which forms methanoic acid on oxidation in the presence of copper at 200ºC.
c) Methane of Methanol
(d) Which has vapour density 14 and turns alkaline KMnO4 green.
Ethene or Ethylene
(e) Which forms chloroform on halogenation in the presence of sunlight.
(e) Methane
(f) Which decolourises bromine solution in carbon tetrachloride.
(f) Ethene or Ethylene; Ethyne or Acetylene.
Write balanced equations for the preparation of the following : -
(a) Ethane from sodium propionate
(a) CaO
C2H5COONa + NaOH → C2H6 + Na2CO3.
b) Ethene from ethanol.
(b) Conc. H2SO4
C2H5OH → C2H4 + H2O.
(c) Ethyne from calcium carbide
c) CaC2 + 2H2O → Ca(OH)2 + C2H2.
(d) Ethanoic acid from ethane.
(d) 2C2H6 + 3O2 → 2CH3COOH + 2H2O.
Name a reagent which can be used to distinguish between Ethane and ethene.
Bromine solution in carbon tetrachloride.
Write the equation for the preparation of ethylene from ethyl alcohol.
Conc. H2SO4
C2H5OH → C2H4 + H2O.
(x) Name a compound which will give acetylene gas when treated with water.
Calcium Carbide.
Write the equations for the following laboratory preparations : -
(a) Ethane from sodium propionate.
(a) CH3CH2COONa + NaOH → C2H6 + Na2CO3.
(b) Ethene from Iodoethane.
(b) CH3CH2I + KOH → C2H4 + KI + H2O.
c) Ethyne from calcium carbide
(c) CaC2 + 2H2O → Ca(OH) + C2H2.
(d) Methanol from Iodomethane.
d) CH3I + KOH → CH3OH + KI.
Draw the structural formula of a compound with two carbon atoms in each of the following cases : - (a) An alkane with a carbon to carbon single bond.
(b) An alcohol containing two carbon atoms.
(c) An unsaturated hydrocarbon with a carbon to carbon triple bond.
