What unknown has a white color, powdery texture, bubbles when an acid is added, insoluble in water, is a good conductor and has a ph of 9 with no change while heating?

Two liquids are poured into a beaker. after a few seconds, the beaker becomes warm. which of the following best describes this reaction? a. an exothermic reaction b. a decomposition reaction c. an endothermic reaction d. a single-displacement reaction