Question

Constanta de viteza pt reactia h2+i2=2hieste de 0. 43l/mol. S la 400grade celsius. Daca Ea=40kcal/mol sa se calculezeconstanta de viteza la 500grade celsius.

Answer 1

H2  +  I2  <==>  2HI , reactie de ordin 2

k = Axela(-Ea/RT)

prin logaritmare =>

lnk = lnA - Ea/RT

scriem ecuatia logaritmata pentru cele doua temperaturi

lnk1 = lnA - Ea/RT1

lnk2 = lnA - Ea/RT2

-----------------------------

lnk2 - lnk1 = -Ea/RT2 - Ea/RT1

=> lnk1 - lnk2 = (Ea/R)(1/T2-1/T1)

=> lnk2 = lnk1 - (Ea/R)(1/T2-1/T1)

=> lnk2 = ln0,43 - (40/2,3)(1/273+500 - 1/273+400)

=> lnk2 = -0,844 - 17,39(-0,000192)

=> lnk2 = -0,847 => k2 = e la 0,847 = 2,33 L/mol