The decomposition of dinitrogen pentoxide to nitrogen dioxide and oxygen is first order. Its rate constant is 1.91 /h.  a. What is its half-life? b. What fraction of dinitrogen pentoxide is decomposed after 28 min? c. How long will it take to decompose 39% of the N2O5?

8) A first order reaction starts with a concentration of reactant equal to 0.040 M. After two hours, the molarity is 0.020M. What is the molarity after four hours? a. 0.015M c. 0.005M e.0.03 М b. 0.010 M d.0.0025 M

36  The reaction C2H5Cl →C2H4  + HCl is first order in C2H5Cl. The rate constant is 1.60 x 10-6/s. In an investigation of the decomposition of C2H5Cl an initial concentration of 0.165 mol/L was used. What will  the concentration of C2H5Cl be after 125 hours? Select one: a. 0.0803 M b. 0.0703 M c. 0.0603 M d. 0.0503M

Given the reaction and its rate law below, what happens to the rate of reaction when the concentration of NO is doubled?   NO (g) + O3 (g) → NO2 (g) + O2 (g) Rate = k[NO][O3]   A. The rate triples.   B. The rate doubles.   C. The rate halves.   D. The rate quadruples.   E. The rate stays the same.

7. DETAILS The first-order rate constant for the conversion of cyclobutane to ethylene at 1000.°C is 101 s ¹. C4H8 → 2 C₂H4 A. What is the half-life of the reaction at 1000."C? [ B. If you started with 3.350 g of cyclobutane, how long would it take to consume 0.4020 g of it? C. How much of a 2.50 g sample of cyclobutane would remain after 0.03430 s? Useful Information: 1.013 bar = 760 torr = 1 atm = 760 mm Hg h = 6.62607x10-34 3.s c = 2.99792 x 108 m/s R = 8.314472 3/mol.K NA = 6.02214 x 1023 1/mol R = 0.08205746 L.atm/mol.K F = 9.648534 x 104 c/mol Equations: K= K (RT)An AG=AHⓇ - TASⓇ MY NOTES pH = pk +log. E = E [A] [HA] 7=45 0.05916 n ASK YOUR TEACHER PRACTICE ANOTHER log Qrxn AG=-RTINK AG=-nFE 1 [A]t In(2) k [A] = [A]okt 1 =kt + [A] 9 [A] t= k[A] [A] 2k -kt -Ea k Ae RT

Consider the following mechanism: NO  → N + O O + O3 → 2 O2 O2 + N → NO2 What is the role of O2?   A. product only   B. intermediate only   C. Both intermediate and product   D. reactant   E. catalyst

The reaction between hydrogen and chlorine is as follows: Cl2(g) + H2(g) → 2HCl(g) Experiments show that this reaction is first order with respect to H2 and one-half order with respect to Cl2. What is the rate law?   a. Rate = k [H2]1/2 [Cl2] b. Rate = k [Cl2] [H2]2 c. Rate = k [Cl2]1/2 [H2] d. Rate = k [Cl2]2 [H2]

The radioactive isotope 99mTc (used in medical stress tests) decays via gamma emission following first order kinetics and has a half-life of 6.02 hours. How long will it take before the radioactivity drops below 5.00% of the initial value?   A.  42.1 hours B.  30.2 hours C.  26.1 hours D.  24.1 hours

Consider the rate law: Rate = k[NO][O,] Which of the following statements is FALSE regarding this rate law? O The value of k will increase with temperature. O The reaction is 2nd order overall. O The reaction is 1st order with respect to O2 The reaction is 2nd order with respect to NO.

Molecular iodine, I2 (g), dissociates into iodine atoms at 652 K, with a first order rate constant of 0.452 s-1.     I2(g) -----> 2I   a.  What is the half life for this reaction?                                     b.  If you start with 0.35 M I2 at this temperature, how long will it take for the concentration of I2 to reach 0.12 M?