The reaction is actually endothermic because delta H is positive, indicating that it absorbing heat.
There will be oil bubbles because oil is more dense than water so therefore they would not mix
The reaction is an exothermic one because heat is released to the surroundings. An exothermic reaction is a chemical reaction where energy is being released as the reaction by light or heat. On the other hand, endothermic reaction needs energy input for the reaction to proceed.