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e) 0.00311 min; 223 minutes P9. (Sec. 13.3) A certain reaction A- Products is a

ID: 703765 • Letter: E

Question

e) 0.00311 min; 223 minutes P9. (Sec. 13.3) A certain reaction A- Products is a first order reaction. Time wise, if its balt life takes 2615 seconds, how long does it take for the reaction, initially at a molar concentration of 1.11 M, to reach a concentration of 0.305 M? Express the final time in minstes a) 4.14 minutes b) 81.2 minutes c) 296 minutes d) 121.7 minutes e) 166.2 minutes P10. (Sec. 13.3) A certain reaction A- Products is a second order reaction. What is the value of the rate constant (k) if initially the concentration of A was 2.77 M and after 115 minutes the concentration of A measured 0.977 M? What is the halclife of this reaction? a) 0.00111 M min: 325 minutes b) 0.00576 M min: 62.6 minutes c) 0.0576 M min: 17.5 minutes d) 0.00697 M1 min: 51.8 minutes e) 0.0437 M1 .min; 8.26 minutes PII. (Sec. 13.3) A certain reaction A Products is a second order reaction. Time wise, if its half-life takes 3945 seconds, how long does it take for the reaction, initially at a molar concentration of 1.75 M, to reach a concentration of 0.125 M? Express the final time in hours a) 50.5 hours b) 58.2 hours c) 10.2 hours d) 14.2 hours e) 25.3 hours P12. (Sec. 13.4) A certain reaction has a rate constant (k) of 135 s at a temperature of 25 c. If the activation energy (Ex) equals 85.6 kJ/mol, what is the frequency factor (A) for the reaction? (R-8.3 1 4 J / mol-K) a) 6.022 x 103 s b) 39.3 s c) 1.365 x 10"s d) 7.453 x 1016s e) 5.128 x 10"s P13. (Sec. 13.4) The following reaction is a second order reaction. Given the following two rate constants and temperatures, calculate the activation energy (Ea), in kJ/mol, for the formation of hydrogen iodide. (H:(g)+1:(g)->2HI(g)] (R-8.314J/mol K) (At 327 °C, Rate Constant-0.00027 M1 & (At 377 °C, Rate Constant 0.0035 M

Explanation / Answer

Ans 9

A - - - > P

First order reaction

Half life t1/2 = 2615 s

Rate constant k = 0.6932/t1/2 = 0.6932/2615

= 0.000265086 s-1 x 60s/min

= 0.0159052 min-1

Initial concentration of A = 1.11 M

Final concentration = 0.305 M

Final concentration = Initial concentration x exp(-k*t)

0.305 = 1.11 x exp(-0.0159052*t)

exp(-0.0159052*t) = 0.27477

-0.0159052*t = - 1.29182

t = 81.22 min

Option B is the correct answer