Question

27) 27) The half life for the decay of radium is 1620 years. What is the rate constant for this first-order process? A) 1.12 x 10-4 yr-1 B) 2.33 x 10-4 yr-1 C) 6.17 x 10-4 yr-1 D) 8.91 x 10-4 yr-1 E) 4.28 x 10-4 yr-1 28) Express the equilibrium constant for the following reaction 28) P4(s) + 5O2(g) - P4010(8) A) K = (021-5 [P4010) B) K [P4][0215 [P4][0215 [P40101 [P4010 CK D) K IPAO21" E) K = (021 29 29) Which of the following acids is the WEAKEST? The acid is followed by its Ka value. A) HCIO, 2.9 10-8 B) HBrO, 2.3 x 10-9 C) HIO, 23 x 10-11 D) HC2H302, 1.8 x 10-5 E) C6H5CO2H, 63 x 10-5

Answer 1

27. t1/2   = 1620 years

   K   = 0.693/t1/2

        = 0.693/1620

         = 4.28*10^-4yr^-1

E.4.28*10^-4yr^-1

28. P4(s) + 5O2(g) ----------> P4O10(s)

     for solids [P4] = 1

                     [P4O10] = 1

K    = 1/[O2]^5

K   = [O2]^-5

A. [O2]^-5

29. lowest ka value acid is weak acid

HIO is weak acid

C. HIO 2.3*10^-11