Question

12. The first-order rate constant for the reaction of methyl chloride (CH₃Cl) with water to produce methanol (CH₃OH) and hydrochloric acid (HCl) is 3.32 ×  10⁻¹⁰ s⁻¹ at 25°C. Calculate the rate constant at 52.1°C if the activation energy is 116 kJ/mol.

_____ ×10^____ s⁻¹
(Enter your answer in scientific notation.)

14. The rate constant of a first-order reaction is 2.75 × 10⁻⁴ s⁻¹ at 350.°C. If the activation energy is 101 kJ/mol, calculate the temperature at which its rate constant is 8.75 × 10⁻⁴ s⁻¹.

_____ °C

15. The rate at which tree crickets chirp is 1.80 × 10² per minute at 28°C but only 40.9 per minute at 6.5°C. From these data, calculate the activation energy for the chirping process.
_______ kJ/mol

Answer 1

• All the three problems can be done by Arrhenius equation. Based on the data the numericals has been done below-
• This is question number 12.

ARXHINING EQUATHON llen T, 2 25'c = 293*, k, = 3.2.7 x 10" At, tq = 52.1963 325.1K , k, = 2 "). Ea z 116 kJ mall 11 6 Gvo T molt du den - den del, 2. H**en 17-4) ostaty log & - log k, = Ea 1 + - +).. 2.303 R. en log By-log 13.32 x 10-10) 2 116.000 14.1) A 2-303 x 8.314 [298 32501 )

• 
  D + 350c2 623K k, 2 R, Z 2.75 X 10 2.75 X 10"44 E -LOI 'ma101000.melho At tq = ? R₂ 2 8.75 X 10 -4 st 2-303 R en boy x *). Motor Lena tu). in ons - 4x = 9:52x10-5 a Tz = tit. 662.34 = 389.3°C. L Ans)
  
• 
  At 28 T, 2 28° c 2 301k, k, 1.8 At, Tq = 6.5°C 2 279.5k, k = 40.9 min Ea = 2 . an hong (int mon) late this) a, Ea 2 49920 o mali = 49.92 KJ man (Aus).
  NOTE- The last problem the rate constant at temperature 28°C is given as 1.80×102 min-1(given in the data) and not 1.80*10^2. I have done the problem based on the data given by you.