How would you synthesise an carboxylic acid just from a primary haloalkane like bromoethane?

Nucleophilic substitution using NaOH to convert haloalkane to primary alcohol. This is a mechanism that you need to know for the exam. Then oxidise the alcohol by refluxing with acidified potassium dichromate to form the carboxylic acid. Reflux needed because if it isn't heated enough, the aldehyde would form instead! Step 1 : RBr + NaOH --> ROH + NaBr Step 2 : ROH + 2[O] --> RCOOH + H2O