{"id":16,"date":"2014-10-21T09:37:24","date_gmt":"2014-10-21T09:37:24","guid":{"rendered":"http:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/enthalpy-of-combustion\/"},"modified":"2014-10-21T09:47:03","modified_gmt":"2014-10-21T09:47:03","slug":"enthalpy-of-combustion","status":"publish","type":"page","link":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/enthalpy-of-combustion\/","title":{"rendered":"Enthalpy of Combustion"},"content":{"rendered":"

1.<\/strong> When a substance was burned, it raised the temperature of 200 cm3<\/sup> of water from 21 o<\/sup>C to 25.5 o<\/sup>C. What quantity of heat that was released by this reaction?<\/p>\n

2.<\/strong> A Bunsen Burner is used to heat 0.5 kg of water from 20.5 o<\/sup>C to 39.5 o<\/sup>C. How much heat energy has been produced?<\/p>\n

3.<\/strong> An alcohol is burned to heat up 100 cm3<\/sup> of water from 10 o<\/sup>C to 18 o<\/sup>C. How much heat energy has been released?<\/p>\n

4.<\/strong> If 0.1 moles of a substance burns to produce enough heat to raise the temperature of 500 cm3<\/sup> of water from 25 o<\/sup>C to 50o<\/sup>C, calculate the enthalpy of combustion of this substance.<\/p>\n

5.<\/strong> 0.05 moles of a fuel was burned and it raised the temperature of 100 cm3<\/sup> of water from 18.2 o<\/sup>C to 24.5 o<\/sup>C. What is the enthalpy of combustion of this fuel?<\/p>\n

6.<\/strong> When 1g of ethanol (C2<\/sub>H5<\/sub>OH) was burned, the heat produced warmed 5 litres of water from 18o<\/sup>C to 18.5o<\/sup>C. What is the enthalpy of combustion of ethanol?<\/p>\n

7.<\/strong> When 1g of Sulphur was burned, the heat produced warmed 110g of water from 180<\/sup>C to 18.5o<\/sup>C. What is the enthalpy of combustion of Sulphur?<\/p>\n

8. <\/strong>0.32g of methanol (CH3<\/sub>OH) was burned and it heated up 200 cm3<\/sup> of water from 19.5 o<\/sup>C to 27.5 o<\/sup>C. Calculate the enthalpy of combustion of methanol.<\/p>\n

9.<\/strong> 0.2g of methane (CH4<\/sub>) was burned and it heated up 250 cm3<\/sup> of water from 18.5 o<\/sup>C to 28.5 o<\/sup>C. Calculate the enthalpy of combustion of methane.<\/p>\n

10.<\/strong> 0.22g of propane (C3<\/sub>H8<\/sub>) was burned and it heated up 150 cm3<\/sup> of water from 21 o<\/sup>C to 31 o<\/sup>C. Calculate the enthalpy of combustion of propane.<\/p>\n

11.<\/strong> Butane (C4<\/sub>H10<\/sub>) is used to heat 175 cm3<\/sup> of water from 22.2 o<\/sup>C to 31.7 o<\/sup>C. What is the enthalpy of combustion of butane if 3g of the gas had been used?<\/p>\n

12.<\/strong> Ethanol, C2<\/sub>H5<\/sub>OH, can be used as a fuel in some camping stoves.<\/p>\n

The enthalpy of combustion of ethanol is \u22121367 kJ mol\u22121<\/sup>.\u00a0 Using this value, calculate the number of moles of ethanol required to raise the temperature of 500 g of water from 18 \u00b0C to 100 \u00b0C.<\/p>\n

Show your working clearly.<\/strong><\/p>\n

13.\u00a0\u00a0\u00a0\u00a0\u00a0 <\/strong>A value for the enthalpy of combustion of butan-2-ol, C4<\/sub>H9<\/sub>OH, can be determined experimentally using the apparatus shown.<\/p>\n

Mass of butan-2-ol burned = 1\u00b70 g<\/p>\n

Temperature rise of water = 40 \u00b0C<\/p>\n

Use these results to calculate the enthalpy of combustion of butan-2-ol, in kJ mol\u20131<\/sup>.<\/p>\n

\u00a0<\/strong><\/p>\n

\u00a0<\/strong><\/p>\n

\u00a0<\/strong><\/p>\n

14.\u00a0\u00a0\u00a0\u00a0\u00a0 <\/strong>Diborane can be used to manufacture pentaborane (B5<\/sub>H9<\/sub>).<\/p>\n

Pentaborane was also considered for use as a rocket fuel because its enthalpy of combustion is \u2212 9037 kJ mol\u22121<\/sup>.<\/p>\n

Calculate the energy released, in kJ, when 1 kilogram of pentaborane is completely burned.<\/p>\n

15.<\/strong>\u00a0\u00a0\u00a0\u00a0\u00a0 A pupil found the enthalpy of combustion of propan-1-ol using the following apparatus.<\/p>\n

(a) In addition to the initial and final temperatures of the water, what other measurements would the pupil have made.<\/p>\n

(b) Describe a change that could be made to the experimental procedure in order to achieve more accurate results.<\/p>\n

(c) The table shows the enthalpies of combustion of three alcohols.<\/p>\n\n\n\n\n\n\n
Alcohol<\/td>\nEnthalpy of combustion\/kJ mol-1<\/sup><\/td>\n<\/tr>\n
methanol<\/td>\n-715<\/td>\n<\/tr>\n
ethanol<\/td>\n-1371<\/td>\n<\/tr>\n
propan-1-ol<\/td>\n-2010<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Why is there a regular<\/strong> increase in enthalpies of combustion from methanol to ethanol to propan-1-ol?<\/p>\n","protected":false},"excerpt":{"rendered":"

1. When a substance was burned, it raised the temperature of 200 cm3 of water from 21 oC to 25.5 oC. What quantity of heat that was released by this reaction? 2. A Bunsen Burner is used to heat 0.5 kg of water from 20.5 oC to 39.5 oC. How much heat energy has been … Continue reading “Enthalpy of Combustion”<\/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-16","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/pages\/16","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=16"}],"version-history":[{"count":2,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/pages\/16\/revisions"}],"predecessor-version":[{"id":39,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/pages\/16\/revisions\/39"}],"wp:attachment":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsechchemu3hwrk\/wp-json\/wp\/v2\/media?parent=16"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}