Hello!
The reaction that the graph represents is
A. Exothermic because Hrxn=-167 kJTo calculate Hrxn we apply the following equation:

Looking at the graph, and at the result of the calculations, we can see that the enthalpy of the products is
lower than the enthalpy of the reagents, because the sign is negative. That means that the reaction
releases energy in the form of heat and that the reaction is
exothermic.
Have a nice day!
Molarity is the molar concentration of the solute dissolved in a volume of a solution. The molarity of the solution prepared by dissolving barium chloride will be 0.085 M.
<h3>What is molarity?</h3>
Molarity is the ratio of the moles of the solute to that of the volume of the solution in Liters. It can be given as,

Here, moles of the barium chloride can be given by the mass and the molar mass and volume is given as 0.450 L.
Substituting values in the equation:

Therefore, 0.085 M barium chloride is the molar concentration.
Learn more about molarity here:
brainly.com/question/26873446
Mixtures are combinations of materials that can be separated by in most cases time. For instance, oil and water is a mixture. You can tell this by placing the two chemicals in a container and shaking them. They will mix and look like one substance, however, they will separate into the two liquids after some time is given. Assuming that "pure substance" is a solution, a substance is similar to a mixture, but the materials used in the solution are not separable. Over time the materials in the containing will not separate. I believe this is the answer you are looking for.