Question

1. Initial rate data at 25.0 °C are listed below for the reaction: 2 HgCl2 (aq) + C,042 (aq) → 2 (aq) + 2 CO2(g) + HgCl(s) Expt. [HgCl2]0 [C:02) Initial rate/Ms? 0.100 0.20 0.100 0.40 3.1 x 105 1.2 x 104 6.2 x 10-5 0.050 0.40 Use the data to determine the rate law for the reaction. 2. At 500 °C, cyclopropane (C3H.) rearranges to propene (CH:CH-CH2): CH. (g) → CH,CH=CH2 (8) The reaction is first order and the rate constant is 6.7 x 10 . a) What is the rate law for the reaction, and; b) If the initial concentration of C3H. is 0.200 M, what is its concentration of after 15 min? 3. Butadiene (C.H.) reacts with itself at 250 °C to form a dimer with the formula CxH12. 2 C.H. (g) →CxH12 (1) The reaction is second order in C«Hs. a) What is the rate law for the reaction? b) If initial concentration of C He is 0.400 M. what is the concentration of C.He after 25 min if the rate constant is 4.0 x 10-2 ':',

Answer 1

1 answer is

We know that Rate a [jh * Rate & (concentration) whese R4 = Final sate, R; = Initial rate f = final concentration, C₂ = Initial concentration n= order of the reaction. From expt. 1, 2 [HgCl) is constant. So Rate of the reaction depends on LS OFa .: q=040, C; = 0.20 R4 = 1.2x104, R; = 3.1x10-5 = 0.31X164 substitute the values in o /l-axlot (o- 31x167 ) = (***)" >> 0.31 x 10 4 2o)" => 4 = (aja "0.40 in na 2 order with respect Goa = 2

from Expt 2, 3. [cond] is constant. so rate of the reaction is depends on only concentration of [Hgch]. Ri - 1.2 X164, Rg = 062x104 (i = 0.1, G = 0.05 substitute all the values in @ Go ) - 09- () = (43)" > (+)'-(+)" :n=1 order with respect Hack = 1 :: order with respect HgCl₂ = 1 order with respect 292 =2 Rate a [Hg Cl]] [COL ² Rate law → Rate = k [kgeby [soa] ? |