Complete the table to show the number of bonds broken and formed: Bonds broken Number Bonds formed Number between carbon and between carbon and hydrogen oxygen between oxygen between hydrogen atoms and oxygen Is the reaction exothermic or endothermic overall? ________________________________________________________________________ The overall energy change is decided by the strength of the bonds that are broken or formed during the reaction. The stronger the bond the larger the energy change. Which bonds are stronger in this reaction the bonds broken or the new bonds formed? – ________________________________________________________________________ 1 Comparing fuels A student wanted to compare the energy released when 4 different fuels burned. These are her results: Hint: subtract the ending temperature from the starting temperature. Fuel Temperature at Temperature at Temperature rise the start in °C the end in °C in °C methanol 25 56 ethanol 18 53 propanol 17 54 butanol 23 63
Complete the table to show the number of bonds broken and formed: Bonds broken Number Bonds formed Number between carbon and hydrogen between carbon and oxygen between oxygen atoms between hydrogen and oxygen Is the reaction exothermic or endothermic overall? ________________________________________________________________________ The overall energy change is decided by the strength of the bonds that are broken or formed during the reaction. The stronger the bond the larger the energy change. Which bonds are stronger in this reaction – the bonds broken or the new bonds formed? ________________________________________________________________________ 1 Comparing fuels A student wanted to compare the energy released when 4 different fuels burned. These are her results: Hint: subtract the ending temperature from the starting temperature. Fuel Temperature at the start in °C Temperature at the end in °C Temperature rise in °C methanol 25 56 ethanol 18 53 propanol 17 54 butanol 23 63
identifying_exo_and_endo.docx