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人教版《选修·化学4》第26面实验2-5、实验2-6中,涉及浓度对化学平衡状态的影响。在上述两个实验中,反应第一次建立平衡时,低浓度时溶液颜色本身比较深,即使再滴加较高浓度溶液,颜色变化并不明显,实验结论说服力差。鉴于此,本人经过多次试验,在滴加顺序和浓度的选择上作出以下改进。在实验2-5中,将酸碱的滴加顺序做一调整:先滴加5滴1 mol/L NaOH溶液,再滴加5滴1 mol/L H_2SO_4,溶液由橙色变为绿色,再由绿色变为橙色,颜色变化明显,易于观
The 26th surface experiment 2-5 and experiment 2-6 of the People’s Education Press “Elective Chemistry 4” involve the influence of the concentration on the chemical equilibrium state. In the above two experiments, when the reaction was established for the first time, the color of the solution was relatively deep at low concentrations. Even if the solution was added at a higher concentration, the color change was not obvious, and the experimental conclusion was poor. In view of this, I have made several tests to make the following improvements in the order of dropping and the choice of concentration. In Experiment 2-5, the order of addition of acid and base was adjusted as follows: first drop 5 drops of 1 mol/L NaOH solution, then drop 5 drops of 1 mol/L H2SO4, the solution changed from orange to green, and then Green turns orange, color changes significantly, easy to view