A teacher demonstrates a chemical reaction. A student observes that the test tube in which the reaction occurs
becomes warm. What is the source of the thermal
energy generated by the reaction?

Select one:

A. potential energy absorbed by the reaction

B. breaking bonds of the reactants

C. kinetic energy absorbed by the reaction

D. energy stored in the reactants

B, breaking bonds of the reactant.

Explanation:

This reaction is taking in energy and we know this because it says it 'becomes warm'.

Endothermic reactions take in heat/energy from the surroundings and bond breaking occurs during an endothermic reaction.

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

24