which one of the following statements is true? the rate of a zero order reaction is independent of concentration. for the first-order reaction a→b, doubling the concentration of a will result in an increase of the half-life. the unit for the rate of a reaction depends on the order of the reaction. for the zero-order reaction a→b, a plot of 1/[a] vs. time will produce a straight line. the rate of a zero-order reaction decreases as the reaction proceeds.