a. Draw both an electron-dot structure and a line-bond structure for vinyl chloride, C2H3Cl, the starting material from which PVC [poly(vinyl chloride)] plastic is made. b. There are two structures with the formula C4H10. Draw them, and tell how they differ.

Change 1,2-ethenediol into 1,2 ethynediol (HOCCOH) by removing one hydrogen atom from each carbon atom and replacing with a triple bond between the carbon atoms. Be sure to add the third rod to represent the triple bond. Draw a Lewis structure for 1,2-ethynediol. A. Identify the electron-pair and molecular geometry around each carbon and oxygen atom. B. What are the bond angles for C-C-O? For C-O-H? C. Can the molecule interconvert or “flip” between different structures in which the –OH group on the two carbon atoms occupy different orientations with respect to each other? If so, how does this happen? If not, why?

The amount of UVA radiation hitting a surface at sea level in a lightly clouded day is about 70W/m2 . About half of that can be absorbed by the skin. A typical carboncarbon bond requires 348 kJ/mol to break. A person lies on the beach for about 1 hour without sunscreen (i.e. fully exposed to UVA radiation). Estimate the number of C-C bonds broken in this person’s back (about 0.18 m2 ) over that period. Assume that the average wavelength of UVA is 335 nm.

Sometimes the way a molecular formula is written helps to determine the way the atoms are connected. Which of the following molecular formulas would be the best way to describe the stick structure shown below? CH3CH₂CH(CH3)CH₂CH3 (CH3)2CHCH₂CH₂CH3 CH3CH₂CH2CH2CH₂CH3 CH3CH₂C(CH3)3 (CH3)2CHCH(CH3)2