Science 8 - 1/2

Pure substance

Only made up of one type of matter.

Mixture

Combinations of different substances.

Mechanical mixture (Heterogenous)

Mixtures in which the individual substances can be seen.

Heterogeneous mixture

Mixtures in which the individual substances can be seen, or which have a non-uniform composition.

Solution

With two or more mixtures, they cannot be seen. It looks pure.

Homogeneous mixture

Mixtures that appear to be a single substance, with a uniform composition throughout.

Suspension

Mixtures in which droplets of one substance are held in another substance.

Colloid

Mixtures in which droplets of one substance are held in another substance but the droplets are so small you cant see them.

What is the difference between a pure substance and a mixture? Give an example of each.

A pure substance is made up of one type of matter (e.g., sugar, alcohol, water), while a mixture is formed from two or more substances combined together (e.g., coffee, milk, sand).

What are the different types of mixtures? Give an example of each.

Mechanical(Heterogenous) mixture (e.g., cookie dough) and Solution(Homogenous) mixture (e.g., coffee, vinegar, air). Suspension(ketchup) Colloid(Milk)

What lab did we do to determine whether a fluid was a pure substance or a solution?

We can use paper chromatography to check whether the fluid is pure or not.

Describe the process of paper chromatography and give examples of practical applications.

1. Paper chromatography uses the fact that surfaces such as paper absorb, or bind different substances by different amounts.2. The solvent (e.g., water) moves through the paper, carrying the dissolved substances with it.3. Substances strongly attracted to the paper move slower than those weakly attracted, leading to separation into bands.4. Applications: Widely used in research and industry to test and separate solutions.

Classify 'chocolate chip cookies'.

Heterogeneous mixture, you can see the different particles.

Classify 'coffee with cream'.

Homogeneous mixture, because it looks pure but has other things in it.

Classify 'aluminum foil'.

Pure substance, its only aluminum.

Classify 'potting soil'.

Heterogeneous mixture, you can see the different particles.

Classify 'gold medal'.

Homogeneous mixture, it looks pure but has more materials in it.

Solute

One that dissolves.

Solvent

One that does the dissolving.

Concentration

Amount of solute dissolved in a specific amount of solvent.

Unsaturated solution

When the solute continues to dissolve.

Saturated solution

When there is no more solute to dissolve.

Solubility

How well a substance can dissolve another.

Saturation point

Maximum capacity that a substance can absorb another.

What is the difference between a solute and a solvent? Give an example of each.

A solute is the one that dissolves (e.g., ice tea packets, sugar), and a solvent is the one that does the dissolving (e.g., water).

Calculate the concentrations in grams per 100 ext{ mL} for the following solutions and identify the least concentrated: A. 10 ext{ g} of chocolate in 50 ext{ mL} of water. B. 3 ext{ g} of sugar in 300 ext{ mL} of water. C. 5 ext{ g} of maple syrup in 25 ext{ mL} of water.

A. (10 ext{ g} / 50 ext{ mL}) imes 100 ext{ mL} = 20 ext{ g}/100 ext{ mL}. B. (3 ext{ g} / 300 ext{ mL}) imes 100 ext{ mL} = 1 ext{ g}/100 ext{ mL}. C. (5 ext{ g} / 25 ext{ mL}) imes 100 ext{ mL} = 20 ext{ g}/100 ext{ mL}. The least concentrated solution is B.

If there was 50 ext{ grams} of sugar in your 250 ext{ mL} Pepsi slurpee, what would the concentration be?

(50 ext{ g} / 250 ext{ mL}) imes 100 ext{ mL} = 20 ext{ g}/100 ext{ mL}.

Describe the difference between unsaturated and saturated solutions.

A saturated solution contains the maximum amount of solute that a solvent can dissolve, meaning no more solute will dissolve. An unsaturated solution has less solute than the solvent can potentially dissolve, allowing for more solute to be added.

List the factors that affect solubility.

The solvent, the solute, the temperature.

What is the difference between a diluted solution and a concentrated solution?

A diluted solution contains a smaller amount of solute dissolved in a given amount of solvent. A concentrated solution has bigger amounts of solute in a smaller amount of solvent.

If a solution has a concentration of 75 ext{ g} per 100 ext{ mL}, what does this mean?

It means that 75 ext{ grams} of solute are dissolved in every 100 ext{ mL} of solution.

What is the solute in an apple juice?

Sugars.

Aqueous solution

Solutions in which water is the solvent.

Supersaturated solution

A solution that contains more dissolved solute than it can normally hold.

Why is water referred to as the universal solvent?

Because it can dissolve almost anything and everything.

Particle Model of Matter

A model that describes matter as being composed of tiny particles that are in constant motion, are attracted to each other, and have spaces between them.

What will happen when you add sand to a beaker filled with marbles?

The sand minerals would go through the cracks and holes of the marbles and fill the empty space.

The process where some particles are more attracted to each other than others is referred to as:

Attraction.

List the four principles of the Particle Model of Matter.

1. All matter is made up of tiny particles.2. The particles are always moving.3. They are attracted to each other.4. The particles have spaces between them.

Describe the movement of particles in a solid, liquid, and gas.

1. Solids: Particles stay tight together and move very little.2. Liquids: Bonds are broken, and they take the shape of the container.3. Gases: Particles are free and have very big spaces between them.

According to the Particle Model of Matter, what factors affect the rate of dissolving of a solute?

1. Temperature: Increasing or decreasing temperature allows the particles to move faster, causing solvent particles to bump into solute particles more frequently.2. Size of pieces: Smaller pieces of solute dissolve more quickly than large pieces due to increased surface area.3. Stirring: Moves all the particles around, forcing solvent particles to bump into solute particles more frequently.

WHMIS

Workplace Hazardous Materials Information System. It is the system in Canada used for classifying and labelling hazardous workplace chemicals, updated to align with the Globally Harmonized System (GHS).

Hazard Symbols

Standardized pictograms used to communicate immediate or long-term dangers associated with hazardous substances.

What is one important lab safety rule regarding touching objects and why is it important?

wear gloves. You dont know what could happen to your hands if you dot wear gloves.

What is one important lab safety rule regarding handling liquids and why is it important?

Never pour liquids in your hand, put it in the test tube rack. If a student pours liquid into their hand, they can spill it on themselves.

Fluid

A material that has no fixed shape, takes the shape of the container, and can pour or flow (usually a gas or liquid).

Hydraulic system

A system that uses liquids to move or lift something.

Hydrometer

An instrument for measuring the density of liquids.

Pneumatic system

A system that uses compressed air.

Describe an example where materials are prepared as fluids for easier movement.

Concrete is turned into a liquid form for easier transport and pouring before it hardens.