A solution is a homogeneous mixture made of two parts:
1. A solvent, which is generally the greater amount and is what does the dissolving.
2. A solute, which is the part that is being dissolved and is the part that breaks into its smallest particles and is equally distributed throughout the solvent.
- amount of solute increases and the amount of solute remains the same.
- amount of solute remains the same and the amount of solute decreases.
2. Use two glasses marked A and B. Pour 1/4 cup of water in glass A . Pour 1/2 cup of water in glass B. Add 6 teaspoons of sugar to each glass and stir well. Taste each solution. Which ratio of sugar to water has the greater concentration of sugar? Glass A ratio= 6 teaspoon sugar: 1/4 cup water Glass B ratio = 6 teaspoons sugar: 1/2cup water Answer: Both glasses contain the same amount of sugar (solute). Glass A has less water (solute) for the sugar to spread out in. As a result, the molecules of sugar are closer together than they are in glass B with more water. Glass A has the greater concentration of sugar.
Ink is a mixture of a dye and a solvent. When ink is used on a surface, when the solvent evaporates the dye is left on the surface.
Inks used for the Janice VanCleave Color Changing Products are water soluble, meaning the solvent is water. The colorants in the color changing inks include a special type of dye called Leuco Dye. Leuco dye molecules have two structural forms, one form is colorless and transparent to visible light. The other leuco dye molecule structure is colored, meaning the molecules absorb part of the visible light spectrum and reflect the remaining part of the light spectrum. The changes in the structural forms of Leuco dye molecules are in response to a specific stimulus.
For more information see Leuco dyes.
Mixtures are the combination or blending of two or more things. There are two different types of mixtures:
Heterogeneous mixtures have an uneven distribution of the different things that have been mixed.
1. Fruit salad made up of apples, oranges, bananas, etc….
2. Combination of iron filings (prepared by grinding up a piece of iron, such as an iron nail) and sand.
3. Rocks are heterogeneous mixtures of different minerals.
Note: While the materials mix to form a heterogeneous mixture keep their own individual physical properties, not all materials in a heterogeneous mixtures are easily separated. The different minerals in rocks for example need special processes to separate.
Homogeneous mixtures have an even distribution of the different things added together.
Solutions are homogeneous mixtures. Solutions are a combination of two parts, a solute and a solvent. When two parts are mixed, the part with the larger volume is generally called the solute. Thus, the solute is the substance that breaks up and is spread throughout the solute.
A sugar solution is a mixture of sugar and water. Sugar is a molecular compound, meaning the smallest part of the sugar compound is a molecule. When sugar crystals dissolve in water, the molecules making up the sugar crystals pull apart and separate molecules of sugar are spread evenly throughout the water. Every drop of the sugar solution has the same number of sugar and water molecules.
Note: Table salt (sodium chloride) is an ionic compound made up of positively charged sodium ions and negatively charged chloride ions. A table salt solution is a mixture of table salt and water. When table salt is dissolved in water, unlike table sugar (sucrose) which is a molecular compound, table salt breaks up into ions. The sodium ions and chloride ions spread evenly throughout the water.
Adding Rigor–This section is not complete.
1. Properties of solutions are called colligative properties.
Colligative properties depend on the concentration of the solution.
Colligative properties include freezing point depression, boiling point elevation, vapor pressure lowering and osmotic pressure.
2. Solvation (Dissolution) is the process of surrounding the solute in a solution with the solvent. Water molecules are polar, meaning they have a positive and negative side. The oxygen atom in each molecule of water has a slightly negative charge while the hydrogen atoms have a slightly positive charge. When sodium chloride dissolves in water, each positive sodium ion is surrounded by water molecules with the oxygen atom pointing toward the sodium ion. The negative chloride ions are surrounded by water molecules with the positive hydrogen ions pointing toward the negative chloride ion.
3. Solution Concentration
Saturated–No more solute can be dissolved at a specific temperature (room temperature).
A Way to Produce a saturated Solution at Room Temperature
I experimented with Cotton Candy, which is a fine webbing of sugar molecules.
I placed the cotton candy on a plate and using a straw let one drop of water fall on the puffy pink candy. Voom! A big hole appeared in the fluffy candy and red drops of liquid started running through the candy as if moving through tiny tubes. Each drop of water did the same thing and finally the candy had disappeared leaving only a small puddle of thick red liquid on the plate as well as on the paper cone the candy had been spun around. There were some sugar crystals on the paper cone as well as in the thick saturated solution in the plate.
Supersaturated Solution is when a solvent is heated above room temperature and more solute than will dissolve at room temperature is dissolved.
Types of Solutions
Solid + Solid
Alloy a homogeneous solution of two or more metals that have been melted, blended evenly together, then allow to cool; also a metal with any nonmetal where the two are evenly blended, such as iron and carbon forming steel.
Solid + Gas–
Gas + Gas– Air
Gas + liquid –Carbon dioxide dissolved in a soda.
Most mixtures can be separated by Physical means.
Methods for separating Homogeneous Mixtures
Methods for separating Heterogeneous Mixtures
A solution is a homogeneous mixture. This mean the mixture is the same throughout.
There are different kinds of solution as shown in the chart.
A solution is made by dissolving a solute in a solvent. The solute is the part that breaks into the tiniest particles making up the solute, then these particles are dispersed (evenly spread) throughout the solvent.
Generally, the solvent is the part with the greater volume.
Solid Compound + Water
There are two types of compounds, ionic compounds, such as table salt and covalent compounds, such as table sugar.
The video very nicely describes what happens when table salt (sodium chloride) and table sugar (sucrose) dissolve in water.