Mixtures and Solutions

What is “Matter?”

Anything that has mass and takes up space or volume

What is matter made of?

Very small particles too small to be seen.

What is the word that means “too small to be seen?”

Microscopic

Describe the property of a solid.

Solids have a definite shape and volume

Describe the particles in a solid.

Particles in a solid are very close to one another and vibrate, but stay in the same place.

How can you measure the volume of a solid that has measurable sides?

You can calculate the volume of a solid with rectangular sides by measuring with a ruler and calculating the height x width x length.

How do you measure the volume of a solid with irregular sides?

Measure the volume of an irregularly shaped solid by water displacement in a graduated cylinder. The volume of water displaced equals the volume of the object.

Describe a liquid.

Liquids have a definite volume, but their shape changes according to the shape of their containers.

Describe the particles of a liquid.

The particles are still relatively close to one another, but they do move apart from each other and flow from place to place.

How do you measure the volume of a liquid?

You measure the volume of a liquid in a graduated cylinder or syringe.

Describe the properties of gases

Gases have no definite shape or volume, but take the shape and volume of their containers filling the space available.

Describe the particles of a gas.

The particles easily move far apart from each other and spread out through the available space.

How do you measure the volume of a gas.

You measure the volume of a gas in a graduated syringe.

What are mixtures?

Mixtures are composed of two or more substances that are mixed together, but can easily be separated from each other.

What happens to the substances in a mixture?

the substances in a mixture do not permanently change in the mixture, but they keep their separate properties

What are solutions?

Solutions are composed of substances that mix so completely that they cannot be distinguished as separate substances.

Can solutions be separated?

They can be easily separated back into the separate substances.

What is the difference between a mixture and a solution?

A solution is usually a mixture of a solid that dissolves completely in a liquid, for example salt or sugar in water.

What is an alloy?

Alloys of two or more solid metals that mix completely for example brass made from a mixture of copper and zinc can be called a solution. The separate substances mix so completely that they cannot be distinguished.

How can a mixture or solution be separated?

Mixtures and solutions can be separated by the processes of filtration, sifting, magnetic attraction, evaporation, chromatography.

How do you use filtration to separate mixtures?

Filtration is used to separating solid particles from a liquid by pouring the mixture through a filter paper in a funnel. The filter paper traps the solid particles and only allows the particles of the liquid to pass through.

When would you use this method?

This method is used, for example, in water treatment plants as part of the process for separating dirt and other solid particles from water to produce clean drinking water.

What is sifting?

Sifting is used to separate smaller solid particles from larger solid particles. The mixture of different sized solid particles is put into a container that has a screen material at the bottom with holes of a certain size. When the mixture is shaken, the smaller particles go through the screen leaving the larger particles in the container.

When would you use sifting?

Cooks, for example, sift flour to get a small particle size for baking leaving larger particles of flour in the sifter above the screen. Sand and gravel companies, for example, separate rocks into different sized particles for road building and other construction projects using this method.

What is magnetism?

Magnetic attraction is used to separating magnetic material from a mixture of other substances. When a magnet is stirred through the mixture, it pulls out the magnetic material from the mixture.

When is magnetism used to separate?

A “cow magnet”, for example, is given to a cow to swallow A “cow magnet”, for example, is given to a cow to swallow. It stays in the first stomach of the cow keeping magnetic materials like wire and other harmful materials that cows swallow from going into the rest of their digestive system.

When is evaporation used to separate?

Evaporation is used to separate a solid that has dissolved in a liquid solution.

How is it used?

The solution is heated until all the liquid turns to a gas (evaporates) leaving the solid behind.

How could evaporation used in real life?

Salt in salt water or ocean water, for example, is separated by heating the solution until all the water evaporates leaving the solid salt in the container.

What is Chromatography ?

Chromatography is used to separate and analyze the solutes (5-4 Chromatography is used to separate and analyze the solutes (5-4.5)in a solution.

Describe chromatography.

A small amount (2-3 drops) of the solution is put on a piece of filter paper, which is put in a solvent (5-4.5). The substances in the solution, called solutes (5-4.5), that dissolve most easily travel the furthest; and substances that do not dissolve easily do not travel very far. The bands of color that are formed, for example, allow scientists to identify the substances in the solution by comparing them to the location of known substances forming bands of color on different filter papers.

How is floatation used in separation?

Floatation is used to separate solids, which float from remaining liquids in a mixture.

Describe how its used.

The solids are stirred and when they float to the top, they are skimmed off the surface of the liquid and put into a different container.

Give a real life example of how this is used.

This method is used, for example, in some water purification plants This method is used, for example, in some water purification plants. Students must be able to separate mixtures using the procedures necessary for each type of separation.

What is a solvent?

in a mixture that is a solution the substance that is in the greatest amount is the solvent, and it is usually the liquid.

What is a solute?

The substance in the least amount is the solute and it is also usually the solid.

What is a concentrated solution?

A concentrated solution contains a greater amount of solute than a solution that is not very concentrated. The greater the concentration of the solution, the greater the amount of solute is in the solution.

What determines the relative concentration of a solution?

The ratio of solute to solvent determines the relative concentration of a solution.

What is the rate of dissolving?

solids (solutes) dissolve in solvents (liquids) in solutions in different amounts in given times,

What does the rate of dissolving depend on ?

Temperature, particle size, stirring,

How does temperature change the rate of dissolving?

If the temperature increases, more of the solute will dissolve faster.

How does particle sizes change the rate of dissolving?

Usually, if the particle sizes are smaller, more of the solute will dissolve faster.

How can stirring change the rate of dissolving?

Stirring can change the rate of dissolving Stirring can change the rate of dissolving. Usually, if the solution is stirred, more of the solute will dissolve faster.

What happens when the substances are combined chemically?

The new substance formed cannot easily be separated into the original components.

Do chemically combinations have the same characteristics as the original substances?

When substances chemically combine, a new substance is formed that does not have any of the characteristics of the original substances that were mixed to form it.

What happens when the substances combined are not chemically combined?

When substances are mixed without being chemically combined, a new substance is not formed, and the substances can be easily separated.

How do pollution and harmful substances in our environment occur?

Pollution or harmful substances in our environment result from the mixing and dissolving of foreign substances in water, air, and soil.

What activities produce pollution?

These harmful substances are often produced as a result of activities associated with industry, agriculture, burning fossil fuels, or other processes associated with human activities.