123103 Chemistry For Modern Sciences Assessment Answer

Include a photo of one of your models and include your Massey ID card in the photo.

Part One:

A:  Change in volume

Observations about the change in volume of water as it freezes.

Calculate the percentage change in volume of the water going from a liquid to a solid.

B:  To float or not to float?

Comparison between ice and fat floating.

Compare results for the ice and the fat when placed in their respective liquids and explain with reference to the ‘structure of a solid’ the different observed results.

[Water is anomalous when compared to most substances in forming a solid that is less dense than the liquid.]

Use web or alternative references to construct your explanation. You can include a diagram in your answer as appropriate, please remember to acknowledge any references you use. (Give a succinct answer, maximum 100 words.)

Part Two:

 Comment on the three dimensional shape of pentane in comparison to the skeletal structure you drew of pentane. Is the skeletal structure a good representation of the three dimensional shape compared to the electron dot structure 

Part Three

Which bond/s allow free rotation between the atoms joined?  

Which bond/s do not allow free rotation between the atoms joined? 

Which models have cis and trans isomers?

Part Four:

Sketch your model (C₂H₃Cl) and indicate the geometry about the carbon atoms.  

Is it possible to construct a different structure using these atoms?Sketch the three structures that can be constructed from C₂H₂Cl₂