NAME: ______

Unit 1:
MIX AND FLOW OF MATTER
SCIENCE 8
Unit Notes
Mr. K

CLASS: ______

Section 1.1 Notes

WHMIS Symbols and Safety Procedures

WHMIS stands for Workplace Hazardous Materials Information System. Many people across the globe recognize these symbols to ensure everyone’s safety when handling these substances.

Section 1.2 Notes

The Many Uses of Fluids

A fluid is…

Fluids Make It Easier to Use Materials

Slurries are a…

(like dirt and water). Slurry technology – the transport of solids in water – has many important applications. You even use a slurry to wash dirt off your driveway (mixture of dirt and water).

Fluids Become Solids

Fluids take the shape of their containers. Many solid materials are originally prepared as fluids. Fluids can also be used to make other solids through superheating. Two examples of this are:

(1)

(2)

The solids are processed as liquids to shape them easier, so then they cool or dry as a solid they are in the form they should be.

Fluids Can Hold Other Materials

The ability of fluids to flow and carry other materials makes them useful in many different applications. Toothpaste is a great example. It has many different ingredients within, and acts as a ‘binder’ that keeps all of the ingredients together for easy use and transport.

Section 2.1 Notes

Pure Substances and Mixtures

Term / Definition / Examples
PURE SUBSTANCE
MIXTURE

All pure substances have their own unique set of properties, or characteristics. All mixtures contain two or more pure substances, which have their own distinct properties (some of which may be hidden). Matter can be classified as follows:

Within the mixtures category, there are several types of mixtures, each with their own set of unique properties.

Term / Definition / Examples
MECHANICAL MIXTURE
*** Mechanical mixtures are also known as…..
SOLUTION
*** Solutions are also known as…..
SUSPENSIONS
COLLOIDS

Matter, including the different types of mixtures, can be classified as in the flow chart to the right.

Homogeneous mixtures are……

Heterogeneous mixtures are…

Paper Chromatography

A filter paper is placed partially in a solution – if the fluid moves up to only one level it is a pure substance – if it moves up to multiple levels showing each substance, then it is a solution.

The filter paper used in the paper chromatography test is called a chromatogram.

Applications of Chromatography

Separation systems are used in a wide variety of industrial and scientific applications. These systems isolate and analyze products that come from mixtures formed during chemical synthesis. Chromatography applications are used in many scientific analyses, including:

-Medical/biomedical research, quality control of pharmaceuticals, routine clinical determination, and drug screening

-Space-related and geo-chemical research and development

-Forensic sciences

-Food and cosmetic chemical measurement

-Process control in the petroleum industry

-Environmental monitoring and pollution control

-Investigation of the chemistry and metabolism of biological systems.

Section 2.2 Notes

Concentration and Solubility

A solution is made up of two parts:

Solute:

Solvent:

Solublemeans to be able to be dissolved in a particular solvent. Solutes and solvents can be gases or liquids.

Water is known as the……

When you dissolve anything into something else you get a ______.

We can measure the amount of SOLUTE in any SOLVENT by calculating the CONCENTRATION of the solution.

Measuring Concentration

The ______of a solution is the actual amount of solute in a specific amount of solvent. For example: 50 grams of solute dissolved in 100 ml of water has a concentration of 50g/100ml.

Comparing Concentrations

To compare concentrations of two solutions, you need to know the amount of solute in the same volume of solvent for each solution.

Solution 1 / 10g of salt in 50ml of water (10g/50ml) / = 20g/100ml
Solution 2 / 25g of salt in 100ml of water (25g/100ml) / = 25g/100ml

Solution 2 has a higher concentration.

Which has a higher concentration? Place a star beside your prediction and then calculate to find the correct answer.

Solution 1 / 12g of salt in 50ml of water (10g/50ml)
Solution 2 / 17g of salt in 100ml of water (17g/100ml)

Saturated and Unsaturated Solutions

  • A ______solution is one in which no more solute will dissolve in a specific amount of solvent at a specific temperature.
  • An ______solution is one in which more solute can be dissolved in a specific solvent at the same specific temperature

Supersaturated solutions - a solution that ______

______

______.

When no more solute can be added to a solution, we say that we have reached the ______…. This is the point of no return. Absolutely no more solute can be added. Unless you change something in the solution. This is all related to the solubility (the maximum amount of solute that can be dissolved in a fixed volume of solvent at a given temperature.)

Section 2.3 Notes

Factors Affecting Solubility

How well a solute dissolves in a solvent depends on three main factors:

(1)

(2)

(3)

Solubility Changes With Temperature

Solubility ______as the temperature of the solvent increases, because more space is provided between the particles for the solute particles to fit (dissolve) into. The reverse is true for a gas though - as the temperature increases, the solubility of a gas, in a liquid solvent decreases.

Thermal Pollution

If the temperature of water increases (warm industrial waste water poured directly into lakes and rivers) then there is less oxygen that can be dissolved in the water because the oxygen “bubbles out” of the water– thus, affecting the living organisms in the water. This is called thermal pollution.

Section 2.4 Notes

The Particle Model of Matter

The Particle Model of Matter attempts to explain how the individual molecules and atoms of matter react and behave in everyday situations. There are four basic points to this theory:

How The Particle Model Explains Mixing Substances

Particles are different sizes and when two substances are mixed, the smaller particles fill the spaces between the larger particles. The particle model also states that particles are attracted to each other. However, in some substances particles can be attracted more to particles in other substances than to its own particles making it more soluble (dissolving faster).

Factors Affecting The Rate Of Dissolving

The speed at which the solute dissolves in a solvent is called the rate of dissolving and can be affected by:

Section 3.1 Notes

Viscosity

Viscosity is…..

Fluids with a ______flow______and have little internal resistance or friction.

Fluids with a ______flow ______and have a greater amount of internal resistance or friction.

We can observe the viscosity of different fluids by doing what is called "the bubble test". In this test, fluids that have a slow moving bubble are said to be…….

Viscosity and the Particle Model of Matter

Fluids with lots of internal resistance……

Fluids with very little or no internal resistance……

The Effect of Temperature on Viscosity

Temperature has an effect on the viscosity of a substance.

/ When thick syrup is poured over hot pancakes, the syrup becomes ______viscous because it is ______and runs over the sides of the pancakes.
When thick oil is added to the engine of a car, the oil ______viscous because it is ______as the engine heats up. /
/ Asphalt (road paving) materials are heated up (making them less viscous) so they can be poured easily before it hardens.

Reminder:

Increasing temperature lowers viscosity

(makes it thinner)

Decreasing temperature increases viscosity

(making it thicker)

Section 3.2 Notes

Density of Fluids

Density is…

Density depends on two things:

Every substance has a different density, because each substance is made up of different particles. The density of a substance depends on the particles it is made up of.

All matter has density, including fluids. We can measure density by dividing the mass of the substance by its volume.

We use the following equation:

The units for density are:

Density Calculations (Triangle Method)

When we need to calculate either the density, mass or volume, we can use the TRIANGLE METHOD to help us out!

Simply cover up whichever value you need to calculate and the other two are shown in their proper placement, be it to multiply or to divide.

Most fluids become MORE DENSE as they cool down to their freezing temperature...

except for water; it becomes LESS DENSE! This is why ice floats on water – it is much less dense in the solid form than in the liquid form.

Heated substances are normally LESS DENSE, while cooled substances become MORE DENSE. The density has to do with the SPACES between the particles.

Density and the Particle Model of Matter

A substance that has a HIGH DENSITY….

A substance that has a LOW DENSITY….

Density does not change as long as the temperature remains the same. As energy is added in the form of heat, the particles move more quickly and further apart, thus increasing the substance's volume. When this happens, the density of the substance decreases because the mass remains constant, but the volume increases. One substance can have different densities, depending on the state it is in.

Changing Density by Changing Concentration

If you add salt to water, you INCREASE the number of particles.

______the number of particles means that you increase the ______, since the______.

Section 3.3 Notes

Buoyancy is the tendency of a substance to float. Buoyant objects take up space in a fluid.

When an object is in a liquid, the force of gravity pulls it down. The liquid itself has a force that acts against the force of gravity. This buoyant force pushes objects upward. Objects that are denser than water will sink (negative buoyancy); objects that are less dense than water will float (positive buoyancy); objects with the same density as water will hover (or, be suspended - (neutral buoyancy), neither sinking nor floating.)

Applications of Buoyancy

Buoyancy has important applications in transportation.

Ships are designed to float in all types of water, regardless of the density of the water.

This is possible because of the Plimsoll Line- which shows how heavily a ship can be loaded in different water conditions.

Different types of waters have different densities, which will cause the ship to float “higher” or “lower” in the water. This is important for maneuvering through water when the ocean or sea floors are not flat.

Hot Air Balloons

As the air inside the balloon is heated, it becomes less dense than the surrounding air. The buoyant force of the air will push the hot air balloon upwards, until the buoyant force equals the force of gravity.

Section 3.4 Notes

Compressibility

The COMPRESSIBILITY of a fluid is…

Objects under compression tend to deform in shape, like a soccer ball when kicked or a basketball when it is bounced.

When force is applied to particles, the way they respond depends on it's state of matter:

  • In a gas....
  • In a liquid………

In a liquid, the particles are close together and do not have a lot of space to move. It is said that liquids are incompressible; that is, they cannot be compressed easily.

Practical Uses and Advantages of Fluid Compression

Compression Danger

If a SCUBA diver stays under water, say at a depth of 100 feet (about 30 meters), for a certain period of time, some amount of nitrogen from the air will dissolve in the water in his or her body. If the diver were to swim quickly to the surface, it is just like uncorking a bottle of soda -- the gas is released. This can cause a very painful condition, and it is sometimes fatal, and is known as decompression sickness or "the bends".

To avoid the effects of quick decompression, the diver must rise slowly so that the gas can come out of solution slowly. If the diver does rise too fast, the only cure is to enter a pressurized chamber in which the air pressure matches the pressure at depth (breathing 100-percent oxygen on the way to the chamber also helps).

Section 3.5 Notes

Pressure in Fluids

Pressure is the amount of force applied to a given area.

Pressure can be calculated as follows:

The units for pressure (p) are in ______

Force is always in ______(N), and area is always in ______(m2).

Pressure and Depth

People who dive deeply are aware of the pressure of the water. This is the pressure exerted by the water on you as you travel deeper.

The pressure increases near the bottom of the water because there is a huge weight of water above. The deeper the water, the more pressure.

Pascal’s Law

Pascal's Law states....

"...that an enclosed fluid transmits pressure equally in all directions."

This is only in a CLOSED system (no holes or openings for fluid escape).

We saw this when we used the syringes - pressure was exerted in all directions in the syringes, which caused them to move up on the other side.

Hydraulics vs Pneumatics

A hydraulic system is…..

BASIC IDEA:

Force that is applied at one point is transmitted to another point using an incompressible fluid. Examples include:

A pneumatic system is…..

BASIC IDEA:

Force that is applied at one point is transmitted to another point using a gas. Examples include:

Mix and Flow of Matter:

Unit Exam Study Guide

  1. Define the following terms:
  2. Solute
  3. Solvent
  4. Solubility
  5. Concentration
  6. Saturation point
  7. Viscosity
  8. Density
  9. Buoyancy
  10. Identify the 8 WHMIS symbols.
  11. List at least three uses of fluids.
  12. Create a table to compare the following, each with an example: mechanical mixture, suspension, colloid, solution, pure substance.
  13. Explain the difference between heterogeneous and homogeneous.
  14. What is the concentration, in grams per 100 mL, for the following solutions:
  15. 5 grams of hot chocolate powder in 25 mL of hot water?
  16. 7 grams of salt in 10 mL of water?
  17. List three factors that affect solubility.
  18. Describe the four points of the particle model of matter
  19. Using the particle model of matter, explain the following properties of fluids:
  20. Viscosity
  21. Density
  22. Solubility
  23. Concentration
  24. How is viscosity affected by temperature?
  25. Calculate the density of each of the following substances:
  26. 2.0 mL of mercury with a mass of 27.1 g
  27. 0.5 mL of cooking oil with a mass of 5.25 g
  28. 2.5 mL of dish soap with a mass of 28.5 g
  29. How is density related to concentration?
  30. Which is more compressible, a liquid or a gas? Why?
  31. If 25 N of force is applied to an area of 7.5 m2, what is the pressure?
  32. Pascal’s Law states that….
  33. Describe the difference between a hydraulic system and a pneumatic system
  34. SCUBA divers can sometimes become sick with “the bends”. Explain what this sickness is, how it is caused and how these patients are treated.
  35. How are submarines able to surface and sink on command?