Question: When sodium hydroxide reacts with a copper nitrate solution, the reaction vessel needs to be kept on ice to slow down the reaction. What best describes this reaction?

  Options: 
 A. an exothermic reaction that absorbs energy
 B. an exothermic reaction that releases energy
 C. an endothermic reaction that absorbs energy
 D. an endothermic reaction that releases energy
Answer: B