The surroundings loses heat to the reaction mixture, therefore, the reaction is endothermic.
Temperature difference = Final temperature - Initial temperature
Temperature difference = 20 °C - 28°C
Temperature difference = - 8°C
Therefore there is loss of heat. The surroundings loses heat to the reaction mixture.
An exothermic reaction is a reaction in which heat is released into the surroundings. The reaction vessels feels hotter.
An endothermic reaction is a reaction in which heat is absorbed from the surroundings. The reaction vessels feels colder.
Since heat is absorbed from the surroundings in the reaction between baking soda and vinegar, the reaction is endothermic.
Learn more about exothermic and endothermic reactions at: https://brainly.com/question/6506846