KI催化H_2O_2分解的速度常数、活化能测定研究

Determination of Rate Constant and Activation Energy of H_2O_2 Decomposition over KI Catalyst

现行的通过量气体体积法测定过氧化氢分解反应速度常数的装置,普遍存在读数不准的问题.本文提出了一种新的测定装置,利用该装置,可以提前知道各时刻被测体系产生的氧气体积,操作方便,读数准确可靠.lnV∞-Vτ~τ直线的线性相关系数,最差的为-0.9996,多数在4个“9”以上.当反应温度分别为15、20、25、30℃时,其速度常数k分别为2.7534×10-4、4.1807×10-4、6.1249×10-4、9.2459×10-4s-1.3次测定结果相对误差均不大于0.6%.直线lnk^1T的线性相关系数为-0.9998,由此求得的E15~30℃=58.33kJ.mol-1,与文献値的相对偏差为0.53%.

Nowadays the apparatus which is used to measure rate constant of H2O2 decomposition are not usually accurate, according to the method of measuring the gas volume. In this paper, a new measuring apparatus is proposed and the volume of oxygen in different reaction time is predetermined. The method is proved to be operationally simple, accurate and reliable. The linear correlation of straight line In （ V∞ - VT ） -T is not less than -0.9996. The rate constants when the reaction temperature are 15℃, 20℃, 25℃ and 30℃ measure 2. 7534 ×10^-4, 4. 1807×10^-4 , 6. 1249 ×10^-4 and 9. 2459 ×10^-4s^ -1 respectively. The relative errors of all 3 measurements are less than 0.6%. The linear correlation of the straight line Ink^- -1/T is -0. 9998. The activation energy of 15 - 30℃ is 58.33 kJ · mol^-1, the relative divergence compared with document value is 0. 53%.