Question:
<em>The diagram shows the potential energy changes for a reaction pathway.</em>
Part 1: Does the diagram illustrate an endothermic or an exothermic reaction? Give reasons in support of your answer.
Part 2: Describe how you can determine the total change in enthalpy and activation energy from the diagram and if each is positive or negative.
Answer:
Part 1: The diagram illustrates an endothermic reaction as the products has a higher potential energy than the reactants do. There is a positive slope of the diagram and there is enough energy to meet the activation energy requirement.
Part 2: You can determine the total change in enthalpy and activation energy from the diagram by the potential energy of the reactants. If the reactants have a high potential energy, then the enthalpy is also high, and if the reactants have a low potential energy, then the enthalpy is low. You can determine if the diagram is positive or negative by knowing if its an endothermic or exothermic reaction. An endothermic reaction is positive because the products are higher than the reactants and a exothermic reaction is negative because the reactants are higher than the products.
Muscular dystrophy is a muscle disease that causes a loss in muscle mass and weakness. Patients with muscular dsytrophy may experience a weakening in their cardiac muscles, causings heart malfunction. Muscular dystrophy can also deteriorate the diaphragm, a muscle that solely aids in respiration, causing a breathing malfunction.
The answer is D, all of the above.
<span>Perhaps surprisingly, lakes and rivers constitute a tiny proportion of the world's total freshwater, so answer (b) is correct. Most of the freshwater on our planet is in fact locked up in ice and glaciers, some 68%. The majority of the rest, 30%, is actually underground, in springs and other groundwater feeders. That leaves just 2% that makes up all the rivers, lakes, ponds and other visible freshwater reservoirs that we see in our day-to-day lives.</span>