When classmate Xiao Ming traveled to Junfeng Mountain, he bottled some spring water from the mountain and brought it back to the laboratory. Under the guidance of the teacher, he conducted experiments

When classmate Xiao Ming traveled to Junfeng Mountain, he bottled some spring water from the mountain and brought it back to the laboratory. Under the guidance of the teacher, he conducted experiments according to the following procedures and prepared

(1) The colloid formed by alum dissolved in water can absorb suspended impurities in the water and make the impurities settle to achieve the purpose of water purification; glass rods are required for filtration operations, and the function of the glass rods is to drain water. ;

(2) Activated carbon has adsorption properties and can absorb pigments and odors in water. There are no new substances in this process and it is a physical change;

(3) Clean water obtained after adding activated carbon It also contains soluble impurities and is a mixture;

(4) In the process of making distilled water, broken porcelain pieces should be placed in the water to prevent bumping.

So the answer is: (1) Accelerate the settlement of suspended particles in water; drainage; (2) Physics; (3) Mixture; (4) Prevent bumping.