Salty science: the best way to separate soluble solutions – scientific american

Key concepts






Perhaps you have mixed sand and salt together and wondered how you could separate them again? Whenever you separate them, are you able to have nightmares of small tweezers, a magnifier and hrs spent picking grains of salt and sand apart? You should not hesitate, there’s yet another way! While using the variations in solubility between salt and sand, you will find the easy "solution" with this problem.


Chemistry typically is the research into matter and the way it behaves and interacts with some other type of matter. Everything around us includes matter. An essential property that matter has is solubility. We think about this once we dissolve something in water. In case your chemical is soluble in water, whenever you blend it with water it’ll dissolve, or disappear. When not soluble, your chemical will not dissolve and you’ll notice, either suspended in water or in the finish in the container.

Each time a chemical is dissolved in the liquid, for instance water, it can make a solution. In the solution, the liquid could be the solvent, as well as the soluble chemical that’s put in and dissolves inside the liquid could be the solute. Even though a solvent dissolves a solute, the 2nd blends in but remains. In the event you evaporated all of the liquid within the solution, you would be playing the dry solute again. Really, this is one way salt is processed in giant salt flats where seawater is progressively evaporated, departing behind immeasureable sea salt.


• Strainer (optional)

• Salt

• Sand

• A napkin

• Magnifier

• Two glass jars with covers

• Calculating cup

• Water

• Teakettle or pot

• Two spoons

• Stove and oven

• Funnel

• Coffee filter

• Spoon

• Oven mitts


• Once the sand has many debris within it, utilize a strainer to strain the big debris and purify the sand.

• Place some salt and sand individually around the napkin and, while using the magnifier, carefully browse the salt and sand. Whoever else detected? How can the scale, shape and hue of the grains of sand match facing the grains of salt?

• Be careful when using the stove and oven, then when handling the boiling water. A grown-up should advise you regarding these steps.


• In the glass jar give a quarter cup of salt then one quarter cup of sand. Put the lid round the jar and shake prior to the salt and sand are totally mixed together.*

• While using the magnifying lens, carefully browse the mixture. Whoever else detected? Is it possible to still start to see the individual grains of salt and sand?

• Fill the teakettle or pot with one or more cup water. Heat water round the stove until it’s boiling. Be careful when using the stove and handling the boiling water. A grown-up should advise you regarding this.

• Very carefully pour half cup of boiling water to the jar and stir this mixture getting a spoon. Be careful when handling the boiling water, that make the jar become hot! (Caution: You have to pour water very progressively, and so the glass jar does not shatter in the rapid alteration of temperature.)

• While using the magnifying lens, carefully browse the solution. Whoever else detected? Is it possible to still start to see the individual grains of salt and sand?

• Place the coffee filter inside the funnel and set the funnel on top in the second glass jar. Progressively pour the entire solution inside the filter. Since the solution seeps using the filter, let it collect inside the second jar.

• Searching within the coffee filter, what can the factor is? Carefully remove any particles within the coffee filter getting a spoon and set them inside the first jar.

• Turn the oven onto 325 levels F. Be careful when using the oven and obtain a grown-up that may help you using this. Place both jars onto a cookie sheet and bake them inside the oven until all of the water has evaporated from their website. This may dominate an hour or so approximately. If you check into the jars to find out simply how much water has evaporated, whoever else detected?

• Turn off the oven and let it awesome lower. (When glass changes temperature very quickly, it might shatter.) Then, using oven mitts, carefully get rid of the jars and let them awesome to 70 levels. They’ll probably be hot!

• Following a jars are awesome, examine carefully their contents while using the magnifier. Whoever else detected? Is it possible to still start to see the individual grains of salt and sand? Is it mixed together or separated?

Extra : Within the finish from the activity, you’ll be able to carefully utilize a calculating cup to look for the volume of salt and sand you wound up with. Do these amounts match the amounts you started with? Why you think this happened?

Extra: A number of chemicals have different amounts of solubility. With the help of brilliance of salt, sugar or those who are to water you will see how soluble each chemical is. Just add each chemical, one teaspoon at any time, with a half-full glass water before you decide to realize that it no longer dissolves if you stir it. Which chemical is regarded as the soluble (dissolves most likely probably the most to the equivalent water) which chemical could be the least soluble?

Extra: How might temperature customize the solubility from the chemical? Try dissolving the same sugar in deep trouble, room-temperature water and ice-cold water, employing the same volume of water each time. How are you affected? Is it possible to consider other variables that could affect solubility?

*Correction (6/11/12): The sentence was edited after posting to eliminate reference to the fluids at the moment inside the activity, only solids —sand and salt— are actually mixed.

Observations and results

If you added the boiling water, did the salt dissolve or disappear? After drying inside the oven, did the salt are available in the second jar and mostly the sand is at the beginning jar?

Salt is soluble in water whereas sand is insoluble (not dissolvable ) in water. If sand were soluble in water, we won’t have beautiful sandy beaches! For this reason, when the boiling water was put in this mixture of salt and sand, the salt should have dissolved, or disappeared, whereas the sand continued to be visible, creating a brown solution with possibly some sand particles stuck round the walls in the jar. Temperature could affect the solubility from the chemical, plus the problem of salt in water the brand new temperature in the boiling water improved the salt’s capacity to dissolve within it. The dissolved salt should have easily made its way using the coffee filter and to the second jar whereas the muddy, undissolved sand particles increased to get stuck round the coffee filter (possibly coupled with some salt too). Following a liquid inside the two jars was evaporated inside the oven, the salt inside the second jar should have become apparent again, mostly just like a crusty white-colored-colored substance alongside and also the feet from the second jar.

More to educate yourself regarding

Matter from

Solutions from

A Soluble Separation Solution from Science Buddies

This activity introduced for you personally along with Science Buddies



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