Chemistry, primary alcohol oxidation

anyone got any idea what you need to do to an alcohol with an oxidising agent, say, acidified sodium dichromate(VI) solution to make it into an aldehyde or a carboxylic acid. also how can you change the yield of the product by changing your method??

with the dichromate, if you do the reaction in the presence of water it will oxidize a primary alcohol all the way to -COOH, do it anhydrous to keep it at the aldehyde stage.

Why the fuck do you want to change the yield? You only want to make it higher, and it's pretty good with shit like jones reagent/pcc/KMnO4. If you are worried about a toxic byproduct (like you get with the dichromate), start studying green chemistry while jacking off other dudes. (also I forget the exact reaction but you can use bleach and HCl to oxidize it.)