{"id":3686,"date":"2023-10-05T18:18:37","date_gmt":"2023-10-05T18:18:37","guid":{"rendered":"http:\/\/localhost\/ecole9ja\/?p=3686"},"modified":"2023-10-05T18:22:47","modified_gmt":"2023-10-05T18:22:47","slug":"week-3-ss3-first-term-chemistry-notes","status":"publish","type":"post","link":"https:\/\/ecolebooks.com\/nigeria\/posts\/week-3-ss3-first-term-chemistry-notes\/","title":{"rendered":"Week 3 – SS3 First Term Chemistry Notes"},"content":{"rendered":"

WEEK THREE
\n<\/strong>Topic: ALKYNES <\/strong>e.gEthyne
\n\t\t\t<\/strong>
\n\u00a0Alkynes are the homologous series of unsaturated hydrocarbon with a general molecular formua CnH2n-2<\/sub>.
\nAlkynes show a high degree of unsaturation than alkenes, hence,t hey are chemically more reactive than the corresponding alkenes or alkanes.
\nExamples are :
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0H
\n\u00a0\u00a0\u00a0\u00a0H \u2013 C = C \u2013 H\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0HC – C = C- H
\n[
\n\u00a0\u00a0\u00a0\u00a0Ethyne.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 H prop-1-yne<\/p>\n

\u00a0ETHYNE
\n<\/strong>Ethyne is the first member of the alkyne series. It has a molecular formula, C2<\/sub>H2<\/sub>, and a structural formular of HC = CH.<\/p>\n

\u00a0Laboratory Preparation
\n<\/strong>Ethyne is usually prepared in the laboratory by the action of cold water on calcium carbide. The reaction is carried out on a heap of sand to prevent the flask from cracking as a result of the large quantity of heat evolved.<\/p>\n

\u00a0Evaluation
\n<\/strong>1.\u00a0\u00a0\u00a0\u00a0Write and name all possible structure of hexyne
\n2.\u00a0\u00a0\u00a0\u00a0How can you prepare a few jars of ethyne in the laboratory?
\nNomenclature: The naming of alkyne are obtained by substituting “ane” in alkaens with ‘ene’.<\/p>\n

\u00a0Physical Properties
\n<\/strong>1.\u00a0\u00a0\u00a0\u00a0Ethyne is a colourless gas with a characteristic sweet smell when pure.
\n2.\u00a0\u00a0\u00a0\u00a0It is only sparingly soluble in water
\n3.\u00a0\u00a0\u00a0\u00a0It is slightly less dense than air.
\n4.\u00a0\u00a0\u00a0\u00a0It is unstable and may explode on compression to liquid.<\/p>\n

\u00a0Chemical Properties
\n<\/strong>1.\u00a0Combustion :- it undergoes combustion reaction in air to form water and carbon(iv) oxide
\n\"\"\/\u00a0\u00a0\u00a0\u00a02C2<\/sub>H2<\/sub> + 5O2<\/sub>2H2<\/sub>O + 4CO2<\/sub>.<\/p>\n

\u00a0NB: In limited air, it burns with very smoky and luminous flame because of its high carbon content. But in plenty of air and appropriate proportion, it burns with non-luminous very hot flame of about 3000o<\/sup>C.
\n2. \u00a0Additional Reaction :-Ethyne undergoes addition reaction to produce unsaturated \u00a0\u00a0\u00a0\u00a0\u00a0product with double bonds and then a saturated compound with single bond.<\/p>\n

\u00a0a. With hydrogen in the presence of nickel as catalyst.
\n H HHH
\n\"\"\/\"\"\/\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0H- C = C \u2013 H + H2 <\/sub> H \u2013 C = C \u2013 H + H2<\/sub> H \u2013 C – C – H
\nethene H H Ethane
\nb. Halogenation: e.g Cl2<\/sub>, Br2<\/sub>, I2<\/sub>
\n\t\tClClClCl
\n\"\"\/\"\"\/\u00a0\u00a0\u00a0\u00a0 H- C = C \u2013 H + Cl2 <\/sub>\u00a0\u00a0\u00a0\u00a0 H \u2013 C = C \u2013 H + Cl2<\/sub> H \u2013 C \u2013 C – H
\n 1,2- dichloroetheneClCl1,1,2,2tetrachloroethane <\/p>\n

\u00a0 Br BrBrBr\u00a0\u00a0\u00a0\u00a0
\n\"\"\/\"\"\/\u00a0\u00a0\u00a0\u00a0C = C \u2013 H + Br2 <\/sub> H \u2013 C = C \u2013 H + Br2<\/sub> H\u2013C \u2013 C – H
\n\u00a0\u00a0\u00a0\u00a0 1,2 – dibromoethane Br Br \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01,1,2,2 -tetrabromoethane.
\nc. Addition of Halides;<\/strong>
\n\t\t\u00a0\u00a0\u00a0\u00a0 Hydrogen halide reacts with ethyne to produce halo-alkene and further halogenation \u00a0\u00a0\u00a0\u00a0produce halo-alkane.
\n\u00a0\u00a0\u00a0 E.g: \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ClCl\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0
\n\"\"\/\"\"\/H \u2013 C = C \u2013 H +HCl H \u2013 C = C \u2013 H + HCl H \u2013 C \u2013 C – H<\/p>\n

\u00a0H Cl H H.
\nChloroethene\u00a0\u00a0\u00a0\u00a0 1,2- dichloro ethane.<\/p>\n

\u00a0d.Addition reaction with water through dilute tetraoxosulphate (vi) acid in the presence of \u00a0\u00a0\u00a0\u00a0CuSO4 <\/sub> as catalyst to form ethanol.
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 H OH\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 H H
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0
\n\u00a0\"\"\/\"\"\/\"\"\/H-C=C-H + H2<\/sub>O H- C = C \u2013 H \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0H- C \u2013 C \u2013 H<\/p>\n

\u00a0 H OH Ethanol
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ethenol
\ne. Addition reaction with alkaline KMnO4<\/sub> added to ethyne, it first turns to green from \u00a0\u00a0\u00a0\u00a0\u00a0purple and then to colourless.
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 O O
\n\"\"\/\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0H \u2013 C = C \u2013 H + 4[O] HO \u2013 C = C- OH
\nKMnO4<\/sub> Ethane dioc acid.<\/p>\n

\u00a03. Polymerization
\n In the presence of complex organic \u2013nickel as catalyst to produce benzene.
\n\"\"\/\u00a0\u00a0\u00a0\u00a03 C2<\/sub>H2<\/sub> C6<\/sub>H6<\/sub>
\n\t\t\"\"\/\u00a0\u00a0\u00a0\u00a03 (H \u2013 C = C \u2013 H ) C6<\/sub>H6<\/sub><\/p>\n

\u00a04. Substitutional Reaction
\na. Withammomiacal solution of copper (1) chloride to form reddish brown copper (I) \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0 dicarbide
\n\"\"\/\u00a0\u00a0\u00a0\u00a0C2<\/sub>H2<\/sub> + 2CuCl Cu2<\/sub>C2<\/sub> + 2HCl
\n\"\"\/\u00a0\u00a0\u00a0\u00a0H \u2013 C = C \u2013 H + 2CuCl Cu \u2013 C = C- Cu + 2HCl
\nb. With ammomiacal silver trioxonitrate (v) to form white silver dicarbide
\n\"\"\/\u00a0\u00a0\u00a0\u00a0C2<\/sub>H2<\/sub> + 2AgNO3<\/sub>Ag2<\/sub>C2<\/sub> + 2HNO3<\/sub>.
\n\u00a0\u00a0\u00a0\u00a0
\n\"\"\/\u00a0\u00a0\u00a0\u00a0H- C = C \u2013 H + 2AgNO3<\/sub> Ag \u2013 C = C \u2013 Ag + 2HNO3<\/sub>.<\/p>\n

\u00a0N.B: Alkynes can be distinguished from alkene by reacting with ammomiacal metals of \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0copper(I) chloride and silver trioxonitrate (vi).
\nUSES<\/strong><\/p>\n

    \n
  1. It is used to produce oxyacetylene flame for cutting and welding of metals\n<\/li>\n
  2. Used in the manufacture of PVC plastics\n<\/li>\n
  3. It is used in miner’s lamp\n<\/li>\n
  4. Used in making synthetic fibre\n<\/li>\n
  5. It is also used in making artificial rubber\n<\/li>\n<\/ol>\n

    \u00a0Test for Unsaturation
    \n<\/strong>Unsaturated compound decolorizes bromine water.<\/p>\n

    \u00a0Evaluation
    \n<\/strong><\/p>\n

      \n
    1. Give a chemical test to distinguish between alkyne and alkene.\n<\/li>\n
    2. Describe a test for unsaturated compounds\n<\/li>\n<\/ol>\n

      \u00a0READING ASSIGNMENT
      \n<\/strong>New School Chemistry by Y. O Osei yawAbabio Page<\/p>\n

      \u00a0WEEKEND ASSIGNMENT<\/strong>
      \n\t\t1.\u00a0\u00a0\u00a0\u00a0The concentration of hydrogen ion in a neutral solution is
      \n\u00a0\u00a0\u00a0\u00a0(a) 10-6<\/sup> moldm-3<\/sup>( b) 10-7<\/sup>moldm-3<\/sup> (c) 5 x 10-7<\/sup> moldm-3<\/sup> (d) 1 x 10-8<\/sup>mol dm-3<\/sup>
      \n\t\t2.\u00a0\u00a0\u00a0\u00a0Hydrogen can be prepared in a large scale using the
      \n\u00a0\u00a0\u00a0\u00a0(a) Harber’s process (b) Down’s process (c ) Bosh Process (d) Contact Process.
      \n3.\u00a0\u00a0\u00a0\u00a0Which of the following hydrocarbons is alkyne?
      \n\u00a0\u00a0\u00a0\u00a0(a ) C2<\/sub>H4<\/sub>\u00a0\u00a0\u00a0\u00a0(b) C2<\/sub>H6<\/sub>\u00a0\u00a0\u00a0\u00a0(c) C2<\/sub>H2<\/sub>\u00a0\u00a0\u00a0\u00a0(d) C3<\/sub>H8<\/sub>
      \n\t\t4.\u00a0\u00a0\u00a0\u00a0The final product of complete reaction between ethyne and hydrogen gas is
      \n\u00a0\u00a0\u00a0\u00a0(a) ethane\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(b)methyl ethane\u00a0\u00a0\u00a0\u00a0( c) ethane\u00a0\u00a0\u00a0\u00a0( d) hydroethyne
      \n5.\u00a0\u00a0\u00a0\u00a0Ethynepolymerises in the presence of organomickelcomplext as catalyst to form
      \n\u00a0\u00a0\u00a0\u00a0(a) polythene\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(b) benzene\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0( c) polythene (d) methyl benzene.<\/p>\n

      \u00a0Theory
      \n<\/strong>1.\u00a0\u00a0\u00a0\u00a0a. Calculate the H+<\/sup> of a solution whose PH is 5.
      \n\u00a0\u00a0\u00a0\u00a0b. State three (3) uses of ethyne
      \n2.\u00a0\u00a0\u00a0\u00a0a. With the aid of labeled diagram, describe the laboratory preparation of ethyne.
      \n\u00a0\u00a0\u00a0\u00a0b. Give a chemical test to distinguish between ethane and ethyne.<\/p>\n","protected":false},"excerpt":{"rendered":"

      WEEK THREE Topic: ALKYNES e.gEthyne \u00a0Alkynes are the homologous series of unsaturated hydrocarbon with a…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,288],"tags":[],"class_list":["post-3686","post","type-post","status-publish","format-standard","hentry","category-posts","category-first-term-ss3-chemistry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/3686","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/comments?post=3686"}],"version-history":[{"count":1,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/3686\/revisions"}],"predecessor-version":[{"id":3687,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/3686\/revisions\/3687"}],"wp:attachment":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/media?parent=3686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/categories?post=3686"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/tags?post=3686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}