For the reaction n2o4(g) m 2 no2(g), a reaction mixture at a certain temperature initially contains both n2o4 and no2 in their standard states (see the defi nition of standard state in section 6.9 ) . if kp = 0.15, which statement is true of the reaction mixture before any reaction occurs? (a) q = k; the reaction is at equilibrium. (b) q 6 k; the reaction will proceed to the right. (c) q 7 k; the reaction will proceed to the left.

Astudent made a graph plotting the progress of a reaction over time. the student forgot to label the y-axis of the graph. a graph is shown with two graph lines. one graph line starts at a higher position on the y axis and slopes downwards towards the right. the other graph line starts at a lower position on the y axis and slopes upwards towards the right. the two graph lines stop short of intersecting each other and continue as separate lines which gradually become straight and parallel to the x axis. a vertical line is shown at a point where the two graph lines finally became parallel to the x axis. this vertical line is labeled equilibrium. the title on the x axis is time and an arrow pointing towards the right is shown above time. the title on the y axis is left blank. what best explains the label that the student should use on the y-axis? amount, because as the amount of product decreases, the amount of reactant increases over time. reaction rate, because forward and backward reaction become equal at equilibrium. amount, because the amounts of reactants and products become constant after equilibrium is reached. reaction rate, as the rate of forward reaction increases and rate of backward reaction decreases over time.

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains