in the school laboratory and at home you can get beautiful single crystals or clusters of small crystals, they cover the different objects (paper clips, figurines made of thread, paper).How to grow crystals of salt dissolved in water?From everyone who wants to spend this interesting experience, required accuracy, attention and precise execution of instructions.
What crystallization?
By dissolving the substance in water, the particles go into solution.The reverse phenomenon is called "crystallization".This process is associated with a change in solubility of the substance at different temperatures.With the gradual cooling from the saturated solution crystals precipitate.The shape of the resulting particles are like cubes, diamonds with sharp, straight edges and smooth sides.Suitable for experience different compounds: sodium chloride, sugar, potassium dichromate, copper sulphate and other substances.They give a different shape and color crystals.The most affordable of the water-soluble compounds - salt.The substance is safe for humans, does not lead to burns in contact with skin or inside the body.Let us find out how fast to grow crystals of salt.
Useful tips
When you need to experience the observance of simple rules.This will in a short time to get the correct form large crystals:
- use demineralized or distilled water;
- grow crystals of substances with good solubility;
- spending experience in a clean container;
- filtered solution (possible through a paper towel).
the process can be observed, but to shake and move the container should not be.Many people wonder how to grow crystals of salt, so that they are of a certain size.All depends on the temperature at which the solution is saturated and also on the presence of undissolved particles and impurities.
With slow cooling large crystals fall, while fast - a lot of medium and small.To cool the jar with a solution left in the cold room and placed in a bowl of water and ice cubes.
What equipment is required for the experience?
Lab "Growing crystals of salt" can be successfully performed in the home.It would take a very simple objects and substances:
- glass bulb or a glass (you can take to the bank);
- pan to heat on a water bath;
- bowl of cold water to which a saturated solution is cooled;
- stick for stirring (glass or wood);
- funnel and filter paper (paper towel);
- thermometer for water;
- copper wire clip;
- thread;
- ice cream stick or pencil;
- half a cup of salt;
- demineralized water.
How to crystals of salt?Instructions for laboratory work
Select in advance dietary salt crystals from the largest, they will serve as seed particles.Tie them to the string, wrap it stick ice cream (the pencil).To postpone the harvest and prepare a saturated solution.Require the use of a heater.Be careful not to spill the hot water does not get burned by the burner.
Progress:
- One teaspoon of salt, pour into a jar with water and put in a water bath (90 ° C).Constantly stir the liquid wand portions until complete dissolution of salt.
- Continue adding substance until it dissolves.Assume that at 100 ° C in 100 ml of water was dissolved 39.2 g of sodium chloride.
- Once saturation is reached, complete heating.Filter the hot liquid to the other bank.
- in Lower still warm with a piece of string solution to initiate the process.
After some time to grow a crystal of salt.His need to get and dry on paper towel.You can spend experience without initiating the crystallization or lower the string tied to a metal clip.It will grow crystals.If you cover them with varnish, they are better preserved.
How to obtain blue crystals?
Copper sulfate is highly soluble in water.This substance can grow large blue crystals.Just be careful to carry out the experience - toxic compound.How to grow crystals of salt, which is a crystalline hydrate of copper sulfate?You can grow a large and very beautiful patterns, if you put in a solution of the initiating particle.To obtain it, is poured into the dish slightly supersaturated solution of copper sulfate and left overnight.From the separated crystals are choosing the one that bigger, tied to a silk thread and dipped in hot saturated solution so that it does not touch the walls and bottom of the can.On the air from copper sulfate bound water evaporates, it becomes a pale greenish powder copper sulfate.It should be dry and ready crystal varnish.
How to grow crystals of salt in the form of letters and figures?
Banks cook according to the instructions brine, copper sulfate, sugar, potassium dichromate (in different dishes).For white substances can use food dyes.Make a thin wire figure or letter.White wool threads carefully wrap it.Lower the prepared skeletons on hangers in the not yet cooled supersaturated solutions that they do not touch the bottom and sides of the cans.After a day or even faster figurines covered with crystals.Take them air dry on a paper towel and cover with colorless nail polish.A few ideas for the grown crystals:
- presentation at the school on the theme "Solutions";
- registration of the report on the laboratory work;
- decoration festive wall newspaper;
- production of Christmas toys for the Christmas tree;
- gifts to friends, teachers, parents;
- create a collection of the grown crystals.
