The force on object one is equal that on object two. The acceleration of object one is twice that of object two. The acceleration of object one is equal that of object two. An object sinks in oil but floats in water. The above situation is not possible.
Oil decreases the gravitational force on an object.
Water increases the gravitational force on an object. The buoyant force on the object in oil is greater than the gravitational force. The buoyant force on the object in water is equal to the gravitational force. Mass is conserved in chemical reactions. Internal energy is conserved in all reactions.