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week 5

posted 14 Aug 2014, 19:51 by Maree Pullar

People are at varying stages of the work at present, so I have included some work from last week for those that haven’t completed it.

To do:

·         Finish doing the NCEA questions we were looking at in the VC

·         Do Act 4F in the learning workbook

·         Read p135-138 in the study guide. In your notes

1.       write a definition for an exothermic reaction and draw an energy level diagram

2.       write a definition for an endothermic reaction and draw an energy level diagram.

3.       Write a definition for enthalpy and write the equation for enthalpy change (DH).

4.       Note: bond making is an exothermic process and bond breaking is exothermic.

The section on “determining enthalpy changes”, DH, is the change in enthalpy. Different quantities of reactants will release/absorb different amounts of energy.  You have to look at the stoichiometry of the balanced equation  and multiply the value of the DH given by the number of moles reacting.

·         Do Act 11B

·         Do Act 4G in the learning workbook

·         Read p144-146 in the study guide on bond energies. When doing these problems I find it easiest to draw a structural formal of the reactants and the products.  Then calculate the energy to break all the bonds on the left hand side and calculate the energy released when the bonds are formed on the right hand side.

DH   =   bond breaking minus bond forming.

I have put a worked example in the attachments.

·         Do Act 11C in the study guide.

·         Do Act 4I in the learning workbook

·         Do worksheet 6 in the attachments.

Ċ
Maree Pullar,
14 Aug 2014, 19:52
ć
Maree Pullar,
14 Aug 2014, 19:53
ć
Maree Pullar,
14 Aug 2014, 19:53
Ċ
Maree Pullar,
14 Aug 2014, 19:54
ĉ
Maree Pullar,
14 Aug 2014, 19:51
ĉ
Maree Pullar,
14 Aug 2014, 19:52
ĉ
Maree Pullar,
14 Aug 2014, 19:52
ĉ
Maree Pullar,
14 Aug 2014, 19:52
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