For the equilibrium 2 NOBr(g) D 2 NO(g) + Br2(g), Kc = 1.56 ´ 10-3 at 300 K. Suppose 0.400 M NOBr is placed in a reaction vessel at 300 K. At a given point, the concentration of Br2 is 0.0134 M. Which of the following statements is true? The value of K will decrease until it is equal to Q. Q < K so the reaction will continue to make more products. Q > K so the reaction will consume products to make more reactants. The value of K will increase until it is equal to Q. Q = K so the system is at equilibrium.

Explanation:

2 NOBr(g) ⇄ 2 NO(g) + Br2(g)

Kc = 1.56 ´ 10-3

Which of the following statements is true?

The reaction quotient (Q) measures the relative amounts of products and reactants present during a reaction at a particular point in time. The Q value can be compared to the Equilibrium Constant, K, to determine the direction of the reaction that is taking place.

- The value of K will decrease until it is equal to Q: This statement is wrong.

Equilibrium constants are not changed if you change the concentrations of things present in the equilibrium. The only thing that changes an equilibrium constant is a change of temperature.

- Q < K so the reaction will continue to make more products.

If Q<K, then the reaction favors the products. the system shifts to the RIGHT to make more products. This statement is true.

- Q > K so the reaction will consume products to make more reactants.

If Q>K, then the reaction favors the reactants. the system shifts to the LEFT to make more reactants. This statement is true.

- The value of K will increase until it is equal to Q: This statement is wrong.

Equilibrium constants are not changed if you change the concentrations of things present in the equilibrium. The only thing that changes an equilibrium constant is a change of temperature.

- Q = K so the system is at equilibrium: This statement is true.

If Q=K, then the reaction is already at equilibrium. There is no tendency to form more reactants or more products at this point. No side is favored and no shift occurs.

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.