Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The Filtering Setup: To filter a mixture, you need a funnel, filter paper, and a container (like a beaker). The filter paper is folded into a cone and placed inside the funnel. When the mixture of is poured, the (filtrate) flows through while the (residue) stays on the paper.
Particle Size: Filtering works based on the size of the particles. If the particle size is larger than the holes in the filter paper (), it is trapped. If it is smaller (), it passes through.
📐Formulae
💡Examples
Problem 1:
A student has a mixture of of water and of chalk dust. How can they get the dry chalk back?
Solution:
The student should use the filtering method.
Explanation:
Chalk is insoluble in water. By pouring the mixture through a funnel lined with filter paper, the chalk particles (which are larger than the holes) will be trapped as residue. The water will pass through as filtrate. The student can then let the residue dry to get the chalk powder back.
Problem 2:
Can a mixture of salt and water be separated using a filter paper?
Solution:
No, filtering will not work for salt and water.
Explanation:
Salt is soluble. When it dissolves, the salt particles break down into such tiny pieces that they are smaller than the holes in the filter paper. Therefore, both the salt and the water will pass through the filter together. To separate salt, you would need to use evaporation instead.