Name______
Date______Per______
Unit 1 Review—Classifying Matter and Properties
1)Classify the following as a substance or a mixture:
BronzemilkSalt
Mixturemixturesubstance
Carbon dioxideNeonSweet tea
Substancesubstancemixture
2)Classify the following as a heterogeneous or homogeneous mixture:
BrassSalt and pepperPizza
HomogeneousHeterogeneousHeterogeneous
Hi-CAirMuddy water
HomogeneousHomogeneousHeterogeneous
3)Classify the following as a element, compound, heterogeneous mixture or homogeneous mixture:
Iron LithiumTopsoil
ElementElementHeterogeneous
Brine (like saltwater)Iron oxide (rust)Oil and vinegar dressing
HomogeneousCompoundHeterogeneous
AlcoholSaltwaterIodine
CompoundHomogeneousElement
4)Classify the following as a chemical or physical change:
Silver tarnishingYogurt spoilingTea brewing
ChemicalChemicalPhysical
Cutting paperBurning trashGas exploding
PhysicalChemicalChemical
Melting plasticA ring stand corrodingBaking bread
PhysicalChemicalChemical
Dissolving saltDry ice sublimingRoadkill decaying
PhysicalPhysicalChemical
5)Are the following intensive or extensive properties? Chemical or physical?
Colorflammablilitymalleability
IntensiveIntensiveIntensive
PhysicalChemicalPhysical
Melting pointvolumemass
IntensiveExtensiveExtensive
PhysicalPhysicalPhysical
Corrosivedensityodor
IntensiveIntensiveIntensive
ChemicalPhysicalPhysical
SolubilityInert (non-reactive)combustible
IntensiveIntensiveIntensive
PhysicalChemicalChemical
6)What are the functions of the following pieces of laboratory equipment:
Beaker – Storage, heating, reaction vessel, NOT ACCURATE FOR MEASURING
Crucible – Porcelain, used to heat to red hot temperatures, usually solids
Evaporating dish – Porcelain, used to heat to red hot temperatures, usually liquids
Watch glass – Used to cover an evaporating dish or beaker
Erlenmeyer flask – Storage, heating, reaction vessel, NOT ACCURATE FOR MEASURING
Graduated cylinder – Used to measure solution volumes. Less accurate than a volumetric pipet
or buret.
Test tubes –Place for reactions to take place, may be heated.
Beaker tongs – Used to pick up and hold hot beakers
Crucible tongs – Used to pick up and hold small items
7)What are the definitions for matter and mass, and what is wrong with these definitions?
Matter is anything that has mass and takes up space.
Mass is the amount of matter in a substance.
The problem is that the two definitions are dependent on each other.
8)Describe a method of how to tell the difference between a homogeneous and heterogeneous mixture.
A Homogeneous mixture has only one phase. (APPEARS TO BE ONLY ONE KIND OF STUFF)
A Heterogeneous mixture has more than one phase. (YOU SEE MORE THAN ONE KIND OF STUFF).
9)Explain the similarities and differences of elements versus compounds. Do the same for substances versus mixtures.
Elements are one kind of atom.
Compounds are two or more atoms chemically combined, with a definite composition.
Elements and Compounds are both substances, have a definite composition.
Mixtures are two or more substances combined. NO DEFINITE COMPOSITION
10)If you are unsure whether a change in matter is a chemical or physical change, what four possible clues could you use to make a decision
Change in color or odor.
Heat or light, absorbed or released
Gas bubbles produced
Precipitate formed – when two liquids are combined and a solid is formed
11)What is the difference between a chemical and physical change? Physical and chemical properties?
A CHEMICAL CHANGE gives you new substances, such as electrolysis separating water into hydrogen and oxygen.
A PHYSICAL CHANGE, the substances remain the same, such as WATER FREEZING.
A PHYSICAL PROPERTY is a quality or condition of a substance that can be observed or measured without changing the substance’s composition, including COLOR, SOLUBILITY, ODOR, DENSITY, MELTING POINT.
A CHEMICAL PROPERTY is the ability of a substance to undergo chemical reactions and to form new substances, such as FLAMMIBILITY.
12)Explain how the particles are moving in a solid, liquid and gas and how affects its properties (i.e.why solids have a definite shape and definite volume).
Particles are vibrating around a fixed point in a SOLID.
Particles are sliding past each other in a LIQUID.
Particles are moving freely in a GAS.
The particles in a solid are NOT able to overcome the forces of attraction between the particles so they remain a solid. Because of the forces of attraction between the particles, they keep a fixed shape and volume.
The particles between liquid particles are attracted to each other and stick together but are able to slide past each other. They have a fixed volume, but no fixed shape.
The particles of a gas are not held together by forces of attraction between the particles.
13)What is the law of conservation of mass? How does it apply to chemical changes?
Mass can neither be created or destroyed in an ordinary chemical process.
The mass of the reactants must equal the mass of the products.
2 grams of Hydrogen react with 16 grams of Oxygen to for 18 grams of water.
14) If exactly 12.00g of carbon are reacted with exactly 32.00g of oxygen gas and the only product formed is carbon dioxide, what is the mass of the product? How do you know?
12 grams of Carbon reacts with 32 grams of Oxygen to form 44 grams of Carbon Dioxide.
You know because matter is not gained or lost, only rearranged.
15)What is the difference between intensive and extensive properties?
An INTENSIVE PROPERTY, such as density, is independent of the quantity or amount observed.
An EXTENSIVE PROPERTY, such as mass or volume, depends on the quantity or amount of matter observed.
For example, the ice in both an ice cube and an iceberg melts at 0° Celsius.
Melting point is an INTENSIVE property. However, the length of time it takes for an ice cube versus an iceberg to melt is affected by the amount of the ice. Therefore the length of time for ice to melt is an EXTENSIVE property.
16)Give all the safety rules for fire safety and for glassware (heating, disposing of, etc.).
If your clothes catch on fire – STOP, DROP and ROLL.
Never leave an open flame unattended.
Heat test tubes pointed away from anyone and heat slowly at an angle.
Strike the match BEFORE you turn on the gas.
Heat all glassware slowly.
Dispose of broken glass in the designated container.
Wear goggles at all times when heating, working with glassware or chemicals.
17) Explain the rule about diluting acids—what is it and why?
Pour the acid into the water, NEVER POUR THE WATER INTO THE ACID.
If you pour the water into the acid it will react violently and splatter, possibly in your face.
18) What is a vapor? What are some examples of substances that can be a vapor? Is oxygen a vapor?
A vapor is a gas for a substance that would normally be a solid or a liquid at room temperature.
Examples: Steam, water vapor, ethanol vapor, mothballs, room deodorizer.
No, Oxygen is not a vapor, because Oxygen is a gas at normal room temperature.
19) There were three alloys that were mentioned in class—what is an alloy? What were the three examples? As what type of mixture would alloys be classified?
An alloy is a mixture of metals.
Steel, Brass, and Bronze are three examples of an alloy.
Alloys would be classified as a mixture of solids.
20) What is a solution? Give examples of things that are solutions where the following are dissolved:
A solution is a homogeneous mixture.
Liquid/liquid- water & vinegar
Solid/ liquid – Salt Water
Solid/solid – Brass, Steel, Bronze, Sterling Silver
Gas/gas – Air
Gas/liquid – Soda, oxygen in lake water, water vapor in air
Gas/solid -I can’t think of any
21) Explain the difference between a solution and a suspension, and how a colloid is similar to each.
A solution is a homogeneous mixture with particles so small you see only one phase, such as salt water, air, or Kool-Aid.
A suspension is a heterogeneous from which particles settle out upon standing, such as a running river or muddy water.
A colloid is a heterogeneous mixture containing particles which are intermediate in size between a suspension and a solution, such as gelatin, paint, aerosol sprays, and smoke.
A colloid is similar to a solution because the particles cannot be separated out with filter paper
and do not settle out over time. Both a colloid and a suspension scatter light (Tyndall Effect).
22)What is density? If I poured three insoluble liquids of different density into the same container, what order would the layers occupy?
Density is the ratio of mass to volume, density = mass/volume (d = m/v)
The layers would order from the least dense on top to the most dense on the bottom.
An example, oil floats on water, water floats on mercury.
2nd example, helium balloons float in air.
23) Mercury metal is poured into a graduated cylinder to a volume of exactly 22.50mL. If the mass of the mercury is found to be 306.0g, what is its density?
d = m/v.
d = 306.0 g / 22.50 ml
d = 13.60 g/ml
24)Ethyl alcohol has a density of 0.789g/mL. You need exactly 200.0mL for a lab, but your station is missing the graduated cylinder, so you only have a digital balance. What mass of ethyl alcohol should you use?
d = m/v
m = d x v
m = 0.789 g/ml x 200.0 ml
m = 157.8 g
25)What is the volume of a wooden cube that has a mass of 47.88g? The density of wood is 0.492g/cm3 (you are using Eastern Red Cedar, if you were curious). What would be the length of the sides of this cube?
V = m/d
V = 47.88g /0.492g/cm3
V = 97.3 cm3
Volume = length x width x height
Cube = all equal sides
L=97.3 cm3
L = 4.60 cm