What is the Structural formula of 4-ethyl-234-trimethyloctane?

Answer 1

Draw a line of 8 carbons, and join them by single bonds. This is the backbone of your molecule, the octane part. Now draw lines to represent the rest of the bonds on the backbone, one above and one below each carbon, and one more at each end ( a total of 18). Imagine the carbons numbered from the left (you could use the right, but you have to pick one.) Put a CH3 group above each of carbons 2, 3 and 4. Put a C2H5 group below carbon 4. Add an H at the end of each empty line. Now check: you should have a total of 13 C's and 28 H's.