为验证硅酸的性质,制备硅酸凝胶,人教版教材化学必修1设计如下实验:在试管中加入3 mL～5 mL 饱和 Na_2SiO_3溶液,滴入1～2滴酚酞溶液,再用胶头滴管滴加稀盐酸,边加边振荡,至溶液颜色变浅并接近消失时停止。静置。仔细观察变化过程及其现象,我们能很快看到略带红色胶冻状物质生成。这 In order to verify the properties of silicic acid, prepare silicic acid gels. The teaching materials required by the People’s Education Edition are as follows: 1) Add 3 mL to 5 mL of saturated Na 2 SiO 3 solution in a test tube, add 1 to 2 drops of phenolphthalein solution, and then use the plastic head. The dropper was added dropwise with dilute hydrochloric acid, and shaking was added while the solution was lightened and stopped when it nearly disappeared. Resting. Observing the changes and their phenomena closely, we can quickly see the formation of slightly reddish jelly material. This