镁的相对原子质量测定实验改进

Experimental Improvement for Determination of Relative Atomic Mass of Magnesium

设计了一种测定镁的相对原子质量的"双量气管"新装置,通过正交实验对测定镁的相对原子质量的主要影响因素进行了探讨,得到了该装置的最佳实验条件为:镁条质量为0.016 0 g,H_2SO_4浓度为2 mol/L,H_2SO_4用量为2 mL。此条件下测得镁相对原子质量为24.322 3,相对误差为0.071 1%。该装置操作简单,有效地克服了传统装置操作繁琐、液面调控不准确以及容易溢水的缺点。实验测定结果达到无机化学实验的要求。

A new device of double eudiometer was designed for measuring the relative atomic mass of magnesium, and the main factors affecting the determination of relative atomic mass of magnesium by orthogonal test were discussed. The results showed that the optimal experimental conditions of the device were magnesium strip mass of 0.016 0 g, H2SO4 concentration of 2 mol/L and H2SO4 dosage of 2 mL. Under above conditions, the atomic mass of magnesium was 24.322 3 and the relative error was 0.071 1%. In addition, this device can effectively overcome the disadvantages of traditional device, such as cumbersome operation, inaccurate control of water level and easy overflow. Therefore, the results reached the requirements of inorganic chemistry experiment.