Which of the following statements best describes the end point of the reaction and when you should stop the timer? Group of answer choices Once the purple color of the initial mixture, caused by the KMnO4, fades After 5 minutes have passed Once the KMnO4 has reacted completely with the malonic acid, turning the solution yellow Once the mixture turns colorless

Describe any thermochemical (heat of reaction) evidence for the Arrhenius concept.

Identify the first chemical step in the production of Portland cement. How is this reaction related to the chemistry that takes place in the carbonation of concrete?

. What does the activation energy for a reaction represent? How is the activation energy related to whether a collision between molecules is successful?

Apply collision theory to explain why powdered zinc reacts to form hydrogen gas faster than large pieces of zinc when both are placed in hydrochloric acid solution.

How do chemists envision reactions taking place in terms of the collision model for reactions? Give an example of a simple reaction and how you might envision the reaction’s taking place by means of a collision between the molecules.

Would either of the following reactions go almost completely to product at equilibrium? a 2NO(g)+2H2(g)N2(g)+2H2O(g);Kc=6.510113 b COCl2(g)CO(g)+Cl2(g);Kc=361016

Describe the effect of each of the following on the rate of the reaction of magnesium metal with a solution of hydrochloric acid: the molarity of the hydrochloric acid, the temperature of the solution, and the size of the pieces of magnesium.

. Explain what it means that a reaction has reached a state of chemical equilibrium. Explain why equilibrium is a dynamic state: Does a reaction really “stop” when the system reaches a state of equilibrium? Explain why, once a chemical system has reached equilibrium, the concentrations of all reactants remain constant with time. Why does this constancy of concentration not contradict our picture of equilibrium as being dynamic? What happens to the rates of the forward and reverse reactions as a system proceeds to equilibrium from a starting point where only reactants are present?

Most barium compounds are very poisonous; however, barium sulfate is often administered internally as an aid in the X-ray examination of the lower intestinal tract (Figure 15.4). This use of BaSO4 is possible because of its low solubility. Calculate the molar solubility of BaSO4 and the mass of barium present in 1.00 L of water saturated with BaSO4.