In Exercise 11.39, if the initial concentration of N2Oj is 0.100 .\1. how long will it take for the concentration to drop to 0.0100 times its original value? The decomposition of N2O5 in solution in carbon tetrachloride is a first-order reaction: 2N2O5—»4NO2 + O2 The rate constant at a given temperature is found to be 5.25 X 10-4 s-’. If the initial concentration of N2O5 is 0.200 M, what is its concentration after exactly 10 minutes have passed?

Iodomethane (CH3I) is a commonly used reagent in organic chemistry. When used properly, this reagent allows chemists to introduce methyl groups in many different useful applications. The chemical does pose a risk as a carcinogen, possibly owing to iodomethanes ability to react with portions of the DNA strand (if they were to come in contact). Consider the following hypothetical initial rates data: [DNA]0 ( mol/L) [CH3I]0 ( mol/L) Initial Rate (mol/Ls) 0.100 0.100 3.20 104 0.100 0.200 6.40 104 0.200 0.200 1.28 103 Which of the following could be a possible mechanism to explain the initial rate data? MechanismIDNA+CH3IDNACH3++IMechanismIICH3ICH3++ISlowDNA+CH3+DNACH3+Fast

Chlorine dioxide, ClO2, is a reddish-yellow gas that is soluble in water. In basic solution it gives ClO3 and ClO2 ions. 2ClO2(aq)+2OH(aq)ClO3(aq)+ClO2(aq)+H2O To obtain the rate law for this reaction, the following experiments were run and, for each, the initial rate of reaction of ClO2 was determined. Obtain the rate law and the value of the rate constant.

The Raschig reaction produces the industrially important reducing agent hydrazine, N2H4, from ammonia, NH3, and hypochlorite ion, OCl−, in basic aqueous solution. A proposed mechanism is Step 1: Step 2: Step 3: What is the overall stoichiometric equation? Which step is rate-limiting? What reaction intermediates are involved? What rate law is predicted by this mechanism?

Isomerization of CH3NC occurs slowly when CH3NC is heated. CH3NC(g) CH3CN(g) To study the rate of this reaction at 488 K, data on [CH3NC] were collected at various times. Analysis led to the following graph. (a) What is the rate law for this reaction? (b) What is the equation for the straight line in this graph? (c) Calculate the rate constant for this reaction. (d) How long does it take for half of the sample to isomerize? (e) What is the concentration of CH3NC after 1.0 104 s?

Candle wax is a mixture of hydrocarbons. In the reaction of oxygen with candle w ax in Figure 11.2, the rate of consumption of oxygen decreased with time after the flask was covered, and eventually' the flame went out. From the perspective of the kinetic-molecular theory, describe what is happening in the flask. FIGURE 11.2 When a candle burns in a closed container, the flame will diminish and eventually go out. As the amount of oxygen present decreases, the rate of combustion will also decrease. Eventually, the rate of combustion is no longer sufficient to sustain the flame even though there is still some oxygen present in the vessel.

The reaction NO(g) + 1/2 Cl2(g) NOCl(g) is first-order in [Cl2] and second-order with respect to [NO]. Under a given set of conditions, the initial rate of this reaction is 620 106 mol/L s. What is the rate of this reaction if the concentration of NO is doubled and the concentration of Cl2 is reduced to half the original value? (a) 6.20 106 mol/L s (b) 124 105 mol/L s (c) 2.48 105 mol/L s (d) 4.96 105 mol/L s

Hydrogen peroxide, H2O2(aq), decomposes to H2O() and O2(g) in a reaction that is first-order in H2O2 and has a rate constant k = 1.06 103 min1 at a given temperature. (a) How long will it take for 15% of a sample of H2O2 to decompose? (b) How long will it take for 85% of the sample to decompose?

Ammonia decomposes when heated according to the equation NH3(g) NH2(g) + H(g) The data in the table for this reaction were collected at a high temperature. Plot In [NH3] versus time and 1/[NH3] versus time. What is the order of this reaction with respect to NH3? Find the rate constant for the reaction from the slope.