I did an experiment which involved synthesizing esters by reacting alcohol and carboxylic acid together. We had some carboxylic acids and some alcohols, which we reacted together. So overall we had 7 test tubes having different esters in it.
Then we added sulfuric acid as a catalyst. Then we put the test tube in the water which was at the temperature 80 degrees Celsius (it was being heated).
After 10 minutes we took the test tubes out and put them in a big beaker filled with cold or normal temperatured water. This was done so that test tubes could cool down.
Then we added distilled water to each one of the test tubes.
We began to sniff the test tubes to identify their odors.
What are the possible errors in this experiment that could lead us to detect wrong smell or no smell?

PLEase HELP..