1. Do you think that the air in your classroom is a homogeneous or a heterogeneous
mixture? Explain your answer. Think: Can you breathe in all parts of the room?
Does the air smell the same in all parts of the room? Is the air temperature the same
in all parts of the room? Can you light a candle in all parts of the room?

I think the air in the classroom is heterogeneous because when a person breathes, they breath the air out of your lungs, which might mix in your DNA or any other unique cells of yourself. That means the air is mixed with different kind of air, and the fact that anyone can release any kind of other gas into the air so it smells or looks different. The air from outside would also make it heterogeneous for the air outside includes many other scents.

2. Scientists call water the universal solvent. Are all substances soluble in water?
Support your answer.

No. As done in the Solubility #2 lab, barium Sulfate, iron oxide, iron nitrate, potassium sulfate is not dissolvable in water, no matter how long you stir.

3. Use the vocabulary from this inquiry to complete the following statements.

Your father stirs a teaspoon of sugar into his coffee every morning. In this example,
the water in the coffee is the __________ and the sugar is the __________ .
The sugar is soluble/insoluble (choose one) in the water. The coffee is an example of
homogeneous/heterogeneous (choose one) mixture.

Explain why you think coffee is the type of mixture you chose.

Your father stirs a teaspoon of sugar into his coffee every morning. In this example, the water in the coffee is the solvent and the sugar is the solute. The sugar is soluble in the water. The coffee is an example of homogeneous mixture. Coffee is a homogeneous mixture because you can dissolve the sugar into the coffee so that you don’t see the little specks of sugar when you dissolve it in, but that you can still taste the sugar. Plus, sugar is a really soluble substance (You can stir in hundreds of teaspoon of sugar, but still the solution would not saturate).

• Saturated: Describes a solution that has dissolved the maximum amount of solute
• Unsaturated: Describes a solution that has a less than the max amount of solute dissolved
• Supersaturated: Describes a solution that has dissolved more than the maximum amount of solute, reached by heating then cooling
• On a graph, the saturated line is in the middle, the unsaturated is below and the supersaturated is above
• Solute – how much of a solid dissolves
• The zone below the saturated curve is unsaturated
• The zone above the saturated curve is supersaturated
• Colder water holds less solute
• Hotter water holds more solute
• For salt, both cold and hot water has the same saturated solute
• For salt, the solubility curve is flat
• All substances have different solubility curves
• Some solubility curves go down (it means that it’s more soluble at lower temperature)

This is the lab for the Solubility vs. Volume sheet data recording thing.

Solubility vs. Volume – Inquiry #9 Lab #2

Describe the physical properties of the substance that remains in the evaporating dish.

The leftover salt looks a bit powdery, with fine particles that don’t look like the original table salt.
Where is the water that was in the salt water solution?

In the air. The water vapour is the water that was in the salt water solution because the heat added to it makes evaporate.
What do you think the substance is that remained in the evaporating dish?

It’s the same as the original salt, it’s just in a different form after the heat was added.
What could you do to identify the substance?

You could test the density of the substance and match it with a known substance.

1. Explain why scientists would classify cereal as a heterogeneous mixture.

Cereal includes different foods such as the wheat cereal, the fruits, the milk, and much more. Cereal is not a solution because the solute (the cereal) does not dissolve into the solvent (the milk).

 2. After a minor traffic accident, the police noticed that a solution had spilled and run off

the roadway onto the shoulder of the road. Describe how you could recover a

sample of this solution from the dirt, rocks, and sand on the road’s shoulder.

You could scoop up the solution from the road, and run it through the desalination system, so hopefully when the solution boils, the dirt, rocks and sand would be separated, and the vapour of the solution would become the full solution. To see exactly what solution it is, you could test out the density and match it with one of the substances available.

3. When a scientist mixed together a number of substances, light, heat, and gas were

produced. The scientist could not separate the new substance using physical

properties like solubility, density, or color. Did the scientist create a mixture, or did

she produce something else? Explain how the product she produced was like and/or

different from the homogeneous and heterogeneous mixtures you have used.

What this scientist made was a compound, a solution or substance that is chemically bound together. By mixing together a number of substances, the scientist created a new substance that included light, heat and gas. Similar to how water is made (by two gases, oxygen and hydrogen bounded together), the result of this substance mix was not expected. When you make a compound, it’s like making a homogeneous or heterogeneous mixture at the same time. The atoms of a same substance can be chemically bound to form a compound, but atoms of the different substances can also be chemically bound to form a compound.

• Mixtures are two substances that are physically mixed together
• Salad dressing – Oil and Vinegar
• Don’t mix well, separate, can be filtered
• Oatmeal + Fruit (Easily separated from cereal)
• Solution – a mixture where one substance spreads evenly throughout another
• All solutions are mixtures
• All mixtures are not solutions
• Kool-Aid is a solution and mixtures because the powder dissolves into the solvent
• Cereal is only a mixture because the fruit does NOT dissolve into the solvent
• Things that you can separate easily
• Charcoal + Water = Mixture
• Over time, mixture will settle out
• Distillation is used to separate solutions
• Milk is both a mixture and solution
• Milk is a mixture before pasteurising
• Milk is a solution as a final product
• Immiscible means it’s not soluble in water
• Food colouring and water mix, but food colouring and oil do not mix

Compound & Mixtures Video Notes

• Join together two elements to create a compound
• Chemical reaction create bonds between atoms
• Mix two elements to make a mixture (not chemically joined, so easier to separate)
• Atoms bonded together are molecules
• Atoms of same element can join to form molecules
• Compounds are two or more atoms of different elements that are chemically bounded together (ie. sulfur and iron)
• Compounds can have different properties due to component elements (Hydrogen and oxygen = water)
• Mixtures are elements that are physically, not chemically, joined

Solubility Reading

• Solubility is the amount of solute that can dissolve in a fixed amount of solvent at fixed temperature
• Substances with greater solubility can dissolve more in a solvent
• Solute is solid or liquid or gas.
• Increased temperature means decreased solubility level
• Pressure is the force pushing against a given area
• Increased pressure on a gas increases solubility (ie. Soda contains dissolved carbon dioxide, that’s why it fizzes out of the can

Solubility Questions

http://www.youtube.com/watch?v=IKimraU21ws

1. How does Mr. Anderson define solubility in the video?

Solubility is the measure of how easy it is for a solute to dissolve in a solvent.

 2. What is the solubility of talc in 100ml of 25Celscius water? Explain why talc has this solubility.

Talc is insoluble. The water, or the solvent, can’t make a solution with a solute like talc. Because water is good at breaking down solids that are charged, and talc is not a charged, talc and water cannot mix together to become a solution.

3. Describe how increasing temperature affects the solubility of solid and liquid solutes.

When you increase temperature, you add energy to the molecules inside the substance. With the faster moving molecules, more solute can be dissolved inside the solvent because the molecules can easily surround the solute.

Notes for the Boiling Point Article

• Water boils at 100℃ at sea level
• Water boils at 70℃ at the top of Mount Everest
• Kinetic energy makes particles of the liquid vaporise
• Boiling point happens when all the molecules throughout the liquid have enough kinetic energy to vaporise.
• Boiling point is the temperature at which the vapour pressure of a liquid is equal to the external pressure
• Some liquid evaporates even when the liquid is below its boiling point
• When vapour pressure inside the bubble is equal to the external atmospheric pressure, bubbles rise to the surface and burst.
• Temperature at this process is the boiling point of the liquid
• Normal boiling point is the temperature which the vapour pressure of the liquid is equal to the standard pressure
• Boiling point of a liquid changes with external pressure

 Question 1: What is the boiling point of water in degrees Celsius and Fahrenheit?

100℃, or 212℉

Question 2: How does the boiling point of water change at altitudes below sea level?

The boiling point only occurs when the vapour pressure inside the bubble is equal to the external atmospheric pressure, so when the altitude that changes the atmospheric pressure changes, then the boiling point of the water would be delayed or early.

Question 3: Does water containing impurities boil at a higher or lower temperature than pure water?

Lower temperature

At the Boiling Point #2 lab, we did almost the same thing as Boiling Point #1 lab: We had a measured amount of water with ice cubes, we boiled it, and the thermometer graphed the data out. But this time, everyone was given a different amount of water, so we saw that different volumes boiled faster or slower. I learned that volume could affect the boiling process, since if the volume is higher, then there would be more liquid to boil and evaporate, which would take more time.

Here’s my group’s graph that the thermometer did for us in Boiling Point #2 Lab.

Here’s my Matter Scrapbook. Please read up until the part that says ‘Under Construction’.

Matter Scrapbook

States of Matter – Brainpop

– Matter is anything that takes up space

– All physical matter is made up of tiny particles called atoms.

– Atoms behave differently depending on the temperature and pressure in their environment

– Water is made up of different molecules. Each molecule is made up of two hydrogen atoms and one oxygen atom

– At room temperature, and at normal atmosphere pressure, the molecules form a liquid.

– Liquids have a fixed volume, but they don’t have a fixed shape

– When you increase the temperature in water, you’re adding energy to it.

– When you add energy to the molecules, then the molecules get excited and move around much faster, more wide apart

– But the states of matter are only physical, so the chemical structures are still the same.

– Unlike liquids, gases don’t have a fixed volume. They have a tendency to expand.

– Solid water is ice

– When you lower the temperature in water, you are removing energy.

– Resulting that the particles do not move around that much.

– Solids are made up of atoms that are locked into a rigid structure

– Solids have a definite shape and a definite volume

– Solids look the same no matter what container you put them in.

– Any matter can be solid, liquid or gas.

– Plasma is electrically charged gas

– Every star in the sky, even the sun, is made up of plasma. Lightning is also made of plasma

– The fluoresce of the lightbulbs are also plasma

– Colloids are a mixture of two phases of matter

– Butter, jello and paint are colloids

– Bose-Einstein condenstate – only created in labs.

– This state is around absolute zero, the coldest possible temperature in the universe