a) iron and copper shavings; Using a magnet. The iron shavings will be attracted by the magnet, while the copper shavings will remain.
b) sand and sawdust; Deposition and filtration. Add water and let stand. The sand will settle to the bottom (the density of the sand is greater than the density of water), and the sawdust will float (the density of the wood is less than the density of water). Separate sawdust and filter the solution of water and sand. The sand will remain on the filter.
c) gasoline and water; Defending, since the density of gasoline is 800 g / l, and the density of water is 1000 g / l. You can use a special device – a separating funnel. Water will collect at the bottom and gasoline will form the top layer. By opening the tap of the funnel, you can easily drain the water, and then, by closing and opening it again, drain the gasoline.
d) a solution of ethyl alcohol in water; Distillation, or distillation. First, alcohol is obtained because the boiling point of alcohol is 78.3C, and then water, because the boiling point of water is 100C.
e) iron filings and sulfur powder. Using a magnet. The iron filings will be attracted by the magnet, and the sulfur powder will remain.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.