Question

Suppose two chemicals are reacted together. It takes 1000 kJ of energy to break the bonds of the reactants and 850 kJ of energy are released by the formation of the products. What is the change in energy for the reaction?


A.0 kJ
B.150 kJ
C.-150 kJ
D.850 kM

Answer 1

I suppose it is B -> 150 kJ
Why positive?? Because it is endothermic reaaction i.e it requires more input energy and the output energy cannot compensate completely for required input energy

For more info about exothermic and endothermic reaction, see
--> http://www.docbrown.info/page03/3_51energy.htm