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.

M = 3.0 M.

Explanation:

Hello there!

In this case, according to the definition of molarity, it turns out possible for us to calculate the required molar concentration of the given volume of solution and moles of solvent by knowing they are divided as follows:

However, since the volume is in liters, we first convert the 2500 mL to L and then calculate the resulting molarity as shown below:

Whereas M stands for molar units of mol/L.

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