To use the laboratory filter, we need to fold it first. But how to fold filter paper? Let’s see the following.
Fold the filter paper in half, and then fold it into a quarter of a circle. Fold it inward to a quarter of a circle. One-sixteenth, and then folded in the opposite direction, and continue to average the filter paper. Open the filter paper, fold a small stack inward at each of the two platforms, and finally make the filter paper.
Do not press on the folds near the concentrated point, otherwise, the center of the filter paper will easily break before filtering. Before use, turn the filter paper to prevent dirt from being brought into your hands during filtering. In the filtrate, wet the filter paper with a hot solvent before hot filtration, and then pour the hot solution quickly, taking care not to make the height of the solution exceed the edge of the folded filter paper.
How to fold a filter paper? Filter paper use steps
1. Fold the filter paper in half and fold it twice to form a 90° center angle. 2. Put the stacked filter paper in three layers on one side and open one layer on the other side to form a funnel. 3. The filter paper should be below the side of the funnel. Pour some water into the mouth of the funnel to make the wet filter paper abut the inner wall of the funnel. Then pour the remaining clear water and set it aside. 4. The lower end of the glass rod should be close to the lower side of the funnel. The tendency of tilting along the glass rod flows into the funnel along with the liquid, and the liquid level cannot exceed the height of the filter paper in the funnel. 5. When the liquid flows down the funnel neck through the filter paper, check whether the liquid flows down the cup wall and pour it to the bottom of the cup.
Otherwise, you should move the beaker or rotate the funnel so that the tip of the funnel is firmly attached to the wall of the beaker.
Separation of filter paper
Filter paper has two types. The one is qualitative type another one is quantitative type. In the application of analytical chemistry, when the inorganic compound is separated by filtration to separate out the precipitate, the residue collected on the filter paper can be used to calculate the loss rate during the experiment. Because the qualitative filter paper will produce more cotton fibers, it is only suitable for qualitative analysis. Quantitative filter paper, especially ash-free filter paper, can resist chemical reactions more effectively after special processing procedures.
Fewer impurities and can be used for quantitative analysis. In addition to filter papers for general laboratory applications, there are many applications for filter papers in daily life and engineering. Coffee filter paper is widely used. The filter paper on the outer layer of tea bags provides high softness and high wet strength. Others use air filter paper for testing suspended particles in the air, and fiber filter paper for different industrial applications.