{"id":47,"date":"2014-10-21T09:50:53","date_gmt":"2014-10-21T09:50:53","guid":{"rendered":"http:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/?page_id=47"},"modified":"2014-10-21T09:50:53","modified_gmt":"2014-10-21T09:50:53","slug":"oxidising-and-reducing-agents","status":"publish","type":"page","link":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/oxidising-and-reducing-agents\/","title":{"rendered":"Oxidising and Reducing Agents"},"content":{"rendered":"

1.<\/strong> Write a half equation for each of the changes shown below and state whether they are oxidation or reduction half-equations.<\/p>\n

a) Hg \u00a0\u00ae \u00a0Hg2+<\/sup><\/p>\n

b) Cr3+<\/sup> \u00ae \u00a0Cr<\/p>\n

c) I2<\/sub> \u00a0\u00ae \u00a0I–<\/sup><\/p>\n

d) F–<\/sup> \u00a0\u00ae \u00a0F<\/p>\n

e) Fe2+<\/sup>\u00a0 \u00ae \u00a0Fe3+<\/sup><\/p>\n

f) Sn2+<\/sup> \u00a0\u00ae\u00a0 Sn4+<\/sup><\/p>\n

g) Fe2<\/sub>O4\u00a0\u00a0 <\/sub>-\u00ae \u00a0Fe3+<\/sup><\/p>\n

h) Cl2\u00a0 <\/sub>\u00ae \u00a0ClO3<\/sub>–<\/sup><\/p>\n

i) O2<\/sub>\u00a0 \u00a0\u00ae\u00a0 H2<\/sub>O2<\/sub><\/p>\n

j) I2<\/sub> \u00ae IO3<\/sub>–<\/sup><\/p>\n

2.<\/strong> In each of the following examples write:<\/p>\n

i) the ion-electron half equation for the oxidation and reduction process<\/p>\n

ii) the overall REDOX equation for the reaction<\/p>\n

iii) the names of the oxidising and reducing agent<\/p>\n

a) A displacement reaction between zinc and silver (II) nitrate<\/p>\n

b) A reaction where calcium is added to dilute hydrochloric acid \u00a0<\/p>\n

c) The reaction of acidified potassium permanganate solution with sodium bromide solution<\/p>\n

3.<\/strong> Which of the following is a redox reaction?<\/p>\n

A\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0NaOH\u00a0\u00a0 +\u00a0\u00a0 HCl\u00a0\u00a0 \u00ae\u00a0\u00a0 NaCl\u00a0\u00a0 +\u00a0\u00a0 H2<\/sub>O<\/p>\n

B\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Zn\u00a0\u00a0 +\u00a0\u00a0 2HCl\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00ae\u00a0\u00a0 ZnCl2<\/sub>\u00a0\u00a0 +\u00a0\u00a0 H2<\/sub><\/p>\n

C \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0NiO\u00a0\u00a0 +\u00a0\u00a0 2HCl\u00a0\u00a0\u00a0\u00a0 \u00ae\u00a0\u00a0 NiCl2\u00a0 <\/sub>\u00a0+\u00a0\u00a0 H2<\/sub>O<\/p>\n

D\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0CuCO3<\/sub>\u00a0 + \u00a02HCl\u00a0 \u00ae\u00a0\u00a0 CuCl2<\/sub>\u00a0 +\u00a0 H2<\/sub>O + CO2<\/sub><\/p>\n

4.<\/strong> During a redox process in acid solution, iodate ions, IO3<\/sub>–<\/sup> (aq)<\/sub> , are converted into iodine, I2<\/sub> (aq).<\/sub><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 IO3<\/sub>–<\/sup> (aq)<\/sub>\u00a0\u00a0\u00a0 \u00ae\u00a0\u00a0 I2<\/sub> (aq)<\/sub><\/p>\n

The numbers of H+ <\/sup>(aq)<\/sub> and H2<\/sub>O(l) <\/sub>required to balance the ion-electron equation for the formation of 1 mol of I2(aq)<\/sub> are, respectively<\/p>\n

A\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6 and 3<\/p>\n

B\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 3 and 6<\/p>\n

C\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 12 and 6<\/p>\n

D\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6 and 12<\/p>\n

5.<\/strong> Iodide ions can be oxidised using acidified potassium permanganate solution. The equations are:<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2I–<\/sup>(aq)\u00a0 <\/sub>\u00ae\u00a0 I2(aq)<\/sub>\u00a0 +\u00a0 2e–<\/sup><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 MnO4<\/sub>–<\/sup>(aq)\u00a0 <\/sub>+\u00a0 8H+<\/sup>(aq)\u00a0 +\u00a0 5e–<\/sup>\u00a0 \u00aeMn2+<\/sup>(aq)\u00a0 <\/sub>+\u00a0 4H2<\/sub>O(l)<\/sub><\/p>\n

How many moles of iodide ions are oxidised by one mole of permanganate ions?<\/p>\n

A\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1.0<\/p>\n

B\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2.0<\/p>\n

C\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2.5<\/p>\n

D\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0 5.0<\/p>\n

6.<\/strong> Stanic chloride (SnCl4<\/sub>) was used in World War 1 as a chemical weapon due to its corrosive and toxic properties. It can be produced by the reaction shown.<\/p>\n

What ion is oxidized in the above reaction?<\/p>\n

7.<\/strong> In which of the following reactions is hydrogen acting as an oxidising agent?<\/p>\n

8.<\/strong> During a redox process, chlorate ions are converted into chlorine.<\/p>\n

The reaction is carried out in acidic conditions to provide H+ ions. How many H+ ions would be required to balance this ion-electron equation?<\/p>\n

A 12<\/p>\n

B 10<\/p>\n

C 8<\/p>\n

D 6<\/p>\n

9.<\/strong> The ion electron equations for the oxidation and reduction reactions that take place in a methanol fuel cell are:<\/p>\n

Combine the two ion-electron equations to give the equation for the overall redox reaction.<\/p>\n

10.<\/strong> Acrylonitrile can be reduced to form CH3<\/sub>CH2<\/sub>CN. Complete and balance the ion-electron equation for the reduction reaction.<\/p>\n

The ion electron equation for the oxidation of copper by nitric acid are shown<\/p>\n

How many moles of copper ions are oxidised by 1 mole of nitrate ions?<\/p>\n

A 0.33<\/p>\n

B 0.67<\/p>\n

C 1.50<\/p>\n

D 3.00<\/p>\n

11.<\/strong> What is the significance of the acronym \u2018OILRIG\u2019 when explaining a redox process.<\/p>\n

12.<\/strong>\u00a0\u00a0\u00a0\u00a0\u00a0 What is meant by a spectator ion?<\/p>\n

13. <\/strong>\u00a0\u00a0\u00a0\u00a0 For the following displacement reactions write down the relevant ion-electron equations and use them to work out the redox equation.\u00a0 Do not include the spectator ions.<\/p>\n

(a) copper metal reacts with silver(I) nitrate solution to form copper (II) nitrate solution and silver.<\/p>\n

(b) chromium metal reacts with nickel (II) sulphate solution to form chromium (III) sulphate solution and nickel.<\/p>\n

(c) magnesium metal displaces aluminium from aluminium (III) oxide.<\/p>\n

(d) copper is displaced from a solution of copper (II) sulphate by sodium metal.<\/p>\n

14.<\/strong>\u00a0 Give the names of two strong oxidising agents and give two uses of each.<\/p>\n

15.<\/strong>\u00a0\u00a0 The ion-electron equations below represent the reduction and oxidation reactions which take \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 place when an acidified solution of dichromate ions react with sulphite ions.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Cr2<\/sub>O7<\/sub>2-<\/sup>(aq)\u00a0 +\u00a0 14H+<\/sup>(aq)\u00a0 +\u00a0 6e–<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2Cr3+<\/sup>(aq)\u00a0 +\u00a0 7H2<\/sub>O(l)<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SO3<\/sub>2-<\/sup>(aq) +\u00a0 H2<\/sub>O(l) \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SO4<\/sub>2-<\/sup>(aq) +\u00a0 2H+<\/sup>(aq) +\u00a0 2e–<\/sup><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/sup>Write the REDOX equation for this reaction.<\/p>\n

16.<\/strong> Sulphur dioxide is added to wine as a preservative.\u00a0\u00a0 A mass of 20 to 40 mg of sulphur dioxide \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 per litre of wine will safeguard the wine without affecting its taste.<\/p>\n

(a) Describe clearly, with full experimental detail, how 0.05 mol l-1<\/sup> iodine solution would be diluted to give 250 cm3<\/sup> of 0.005 mol l-1<\/sup> solution.<\/p>\n

(b) The equation for the reaction which takes place is:<\/p>\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 SO2(aq)<\/sub>\u00a0 +\u00a0 I2(aq)<\/sub>\u00a0 +\u00a0 2H2<\/sub>O(l)<\/sub>\u00a0\u00a0 \u00ae\u00a0\u00a0 4H+<\/sup>(aq)\u00a0 +\u00a0 SO4<\/sub>2-<\/sup>(aq)\u00a0 <\/sub>+\u00a0 2I–<\/sup>(aq)<\/sub><\/p>\n

(i) The indicator used in this reaction causes a change from blue to colourless at the end point. Name a substance which could be used as this indicator.<\/p>\n

(ii) Write the ion-electron equation for the reduction reaction taking place.<\/p>\n","protected":false},"excerpt":{"rendered":"

1. Write a half equation for each of the changes shown below and state whether they are oxidation or reduction half-equations. a) Hg \u00a0\u00ae \u00a0Hg2+ b) Cr3+ \u00ae \u00a0Cr c) I2 \u00a0\u00ae \u00a0I– d) F– \u00a0\u00ae \u00a0F e) Fe2+\u00a0 \u00ae \u00a0Fe3+ f) Sn2+ \u00a0\u00ae\u00a0 Sn4+ g) Fe2O4\u00a0\u00a0 -\u00ae \u00a0Fe3+ h) Cl2\u00a0 \u00ae \u00a0ClO3– i) O2\u00a0 … Continue reading “Oxidising and Reducing Agents”<\/span><\/a><\/p>\n","protected":false},"author":2454,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-47","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/pages\/47","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/users\/2454"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/comments?post=47"}],"version-history":[{"count":2,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/pages\/47\/revisions"}],"predecessor-version":[{"id":50,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/pages\/47\/revisions\/50"}],"wp:attachment":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/media?parent=47"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}