Mixture
A combination of two or more substances where each keep their own properties and can be easilty separated. ie. gravel and water. trail mix
Physical Change
Make a difference in the appearance of something without changing what the material is made of.
Solution
A mixture of one substance dissolved evenly into another.
Dissolve
Melt, Make a solution out of, or turn into a liquid
Evenly Distributed
When the solid dissolves, it breaks up into tiny pieces and spreads evenly throughout the liquid.
Substance
A part of a mixture.
Examples of Mixtures
1. Water and Iron Filings
2. Aluminum Cans and Iron Cans
3. Salt and Sand
4. Pepper and water
Examples of Solutions
1. Salt and Water
2. Sugar and Water
3. Tea and Water
Examples of Substances
1. Water
2. Alcohol
3. Oil
4. Food coloring
Describe a procedure that could separate a mixture of sand and table salt.
1. Add water to the mixture to dissolve the salt, 2. filter the mixtures
3. the sand will remain in the filter paper,
4. the salt solution will pass through,
5. evaporate the water from the salt solution to obtain the salt
How are mixtures and solutions alike?
1. In both Mixtures and Solutions, two or more substances are physically combined.
2. Both are made of matter.
How are mixtures and solutions different?
In solutions, one substance is dissolved into the other, but in mixtures substances do not dissolve.
Name Four Ways to Separate Mixtures
1. Magnetism (one substance must have iron)
2. Filtration (strainer, sieves, filters)
3. Evaporation
4. Condensation
Which dissolves more quickly in water?
1. Large pieces of a solute
2. Small pieces of a solute
Small pieces because more of the solute is touching the water when it is in small pieces, so it will dissolvemore quickly.
Evaporation
Used to separate a solid that has dissolved in a liquid solution.
Solute
1.The substance in a solution that is the least amount is the solute.
2. The solute dissolves in the solvent to form a solution.
Solvent
1. The substance in a solution that is in the greatest amount is the solvent.
2. The solvent is usually the liquid. (i.e. water)
What factors affect the rate that a substance will dissolve?
1. If the temparature increases, more of the solute will dissolve faster.
2. if the particle sizes are smaller, more of the solute will dissolve faster.
3. if the solution is stirred, more of the solute will dissolve faster.
Name three ways the solute will dissolve faster.
1. If the temparature increases
2. if the particle sizes are smaller,
3. if the solution is stirred.
Which property of sugar remains after sugar is dissolved in water? color, taste, shape, texture?
Taste
Solubility
The ability of a solute to dissolve in a solvent.
When you mix 2 solid materials together and add water, the mixture starts to bubble and a clear liquid forms with a precipitate on the bottom. How do you separate the precipitate from the liquid?
Filter it through coffee filter.
When you filter out a precipitate from a solution, why does it stay in the filter while the solution passes through it?
The particles of the precipitate are larger than the particles in a solution. The larger particles get caught in the filter and the solution passes through the filter.
How do you know if a liquid is a solution?
You can try to evaporate out the solution and see if anything is left behind after the solvent evaporates.
How is rock candy made with sugar and water?
The mixture of water and sugar is heated to ensure the solution is fully saturated with sugar. As it cools, the sugar comes out of the supersaturated and attaches to the stick or string and form crystals in the process.
If solution A has 20g of solute in it. Solution B has 10g of solute in it and Solution C has 25 g of solute and they all use 50 ml of water as the solvent. List the concentrations from most concentrated to least concentrated.
C A B
If you add 5g of sugar to 50ml of water. what is the total mass of the solution?
55g
If you add an unknown amount of a solid to 100ml of water. How can you calculate the amount of solute that you added?
You will find the mass of the total solution and subtract out 100 g (the mass of the water) and what ever is left is the mass of the solute.
Solution 1 = 50 ml water + 2 spoons solid
Solution 2= 200 ml water + 8 spoons solid
If you compare exactly 50 ml of each solution, which one has a greater mass?
The are identical because
2 spoons/50 ml = 8 spoons/200 ml
Solution 1 = 150 ml water + 3 spoons solid
Solution 2= 300 ml water + 5 spoons solid
If you compare exactly 50 ml of each solution, which one has a greater mass?
3spoons/150 ml water > 5 spoons/300ml water
Solution 1 is more concentrated so it will have a higher mass.
Soft drink powder dissolving in water is an example of a .......
mixture
An example of a chemical reaction
a skateboard is left outside in the rain and it starts to rust.
If you have a solution made of 10g sugar and 20ml of water and you want to make it half as concentrated, what can you do?
Add another 20 ml of water.
A student adds 4 scoops of a solid to 100ml of water. The solution is clear and there is nothing on the bottom of the cup. One spoon of the solid has a mass of 5g. What is the mass of the solution?
120g
A student adds 5 scoops of a solid to 200ml of water. The solution is clear and there is nothing on the bottom of the cup. One spoon of the solid has a mass of 3g. What is the mass of the solution?
215g
The mass of 200ml of a solution is 236g. If we evaporate the water from the solution, what will the mass of the remaining solid be?
36g
If a solution is made from 200ml of water and 40g of solid, how will the mass of the solution compare to the mass of the water alone?
The solution's mass is greater than the mass of the water alone. The water's mass is 200g and the solutions mass is 240g.
When looking at a chemical equation the reactants and the products have the same number of atoms. Why is this?
In every chemical reaction the same amount of atoms goes into a reaction as comes out. Therefore you must have the same number of atoms on each side of the equation.
Look on pg 45 in your book for an example.