Question 3
Sodium hydrogen carbonate solution is prepared by stirring 10 cm³ sodium hydrogen carbonate into 80 cm³ water until no more dissolves. Place 20 cm³ of the solution in a small beaker, measure its initial temperature, then add 5 cm³ calcium chloride. Is the reaction between sodium hydrogen carbonate and calcium chloride endothermic or exothermic? Give a reason for your answer.
