Chemistry 1-1 Unit 2

A 56 g sample of peanut oil has a volume of 60.9 cm³. Calculate the density of the peanut oil. Remember to use the correct number of significant digits in your answer.

0.92 g/cm3

A sample has a mass of 35.4 g and a volume of 36.82 mL. What is the density of the sample?

0.961 g/mL

Ca

Calcium

C

Carbon

Cl

Chlorine

Cu

Copper

All organic compounds are found in living organisms.

False

Density is inversely proportional to pressure.

False

Plastic products are made from inorganic compounds.

False

The Mohs hardness scale increases linearly from 1 to 10.

False

The density of a gas cannot be measured.

False

The physical properties of a compound are similar to those of its elements.

False

Au

Gold

He

Helium

H

Hydrogen

How many naturally occurring elements are there?

92

There are _____ naturally occurring elements.

92

Al

Aluminum

Ba

Barium

Sn

Tin

Diamond will scratch quartz.

True

Hardness and density are physical properties.

True

Hardness is a physical property.

True

Platinum will scratch gold.

True

The various components of a mixture do not combine chemically.

True

Unknown compounds can usually be identified based solely on their physical properties.

True

Zn

Zinc

phase change

a change from one state of matter to another

The usual units of density are:

g/cm3

metals

good conductors of electricity

Elements listed in vertical columns of the periodic table: have similar chemical properties have similar physical properties are metals can combine with each other chemically

have similar chemical properties

Which of the following is not a phase change? melting of snow evaporation of water from the ocean condensation of water vapor to form clouds hydrogen and oxygen gas combining to form water vapor

hydrogen and oxygen gas combining to form water vapor

The rocks and minerals of the Earth consist of _________ compounds.

inorganic

NaCl: phenol (C6H6O): C2H6: Ca3(PO4)2: formaldehyde (CH20): MgCO3:

inorganic organic organic inorganic organic inorganic

All man-made and most carbon-based compounds are

organic

Alexandria

original site of alchemy

nonmetals

poor conductors of electricity

Hardness is indirectely related to: surface roughness strength of chemical bonds mass weight

strength of chemical bonds

Hardness is related to:

strength of chemical bonds

nonmetal

the group of elements that are poor conductors of electricity and heat

atom

the simplest unit of an element that still retains the properties of that element

compound

two or more elements joined together such that the elements have lost their individual identity

What does the term "compound" mean?

two or more elements joined together such that the elements have lost their individual identity in favor of a new set of properties

Helium has a density of 1.79 x 10-4 g/mL at standard temperature and pressure. A balloon has a volume of 6.3 liters. Calculate the mass of helium that it would take to fill the balloon.

1.1 g

Chlorophyll a is one of the green pigments found in plants. Chlorophyll a has the molecular formula /C55/H72/Mg/N4/O5/. How many atoms are in this molecule?

137

Gelatin has a density of 1.27 g/cm3. If you have a blob of gelatin dessert that fills a 2.0-liter bottle, what is its mass?

2,500 g

Researchers have discovered that a moon rock brought back by the Apollo astronauts has a mass of 5.671 kg and a volume of 1,698 cm3. What is the density of the rock? Remember to use the correct number of significant digits in your answer.

3.340 g/cm3

A gold nugget has a volume of 20.0 cm3 and its density is 19.3 g/cm3. What is the mass of the gold nugget?

386 g

Fe

Iron

Why does a weather balloon filled with Helium rise?

Its density is less than air.

Why does ice float after it crystallizes?

Its density is less than water.

Mg

Magnesium

Mn

Manganese

The name of the commonly used hardness scale is:

Mohs

Ni

Nickel

N

Nitrogen

O

Oxygen

Plants make glucose by a chemical process called:

Photosynthesis

grinding glass: rusting of iron: burning a candle: sanding wood:

Physical Chemical Chemical Physical

alloy

a homogeneous mixture of elements with metals to form metallic solids

solution

a homogeneous mixture, usually a liquid with some substance dissolved in it

element

a primary substance that cannot be divided into separate substances

Law of Constant Composition

a pure compound consists of exactly the same elements in the exact same ratios by mass

Which has the greater density? air at sea level air at 20km altitude

air at sea level

For each item, choose whether the change is a physical change or a chemical change. exploding firecracker: mowing grass: breaking a window: spreading butter on toast: burning wood in a fireplace: acid rain corroding gravestones:

chemical physical physical physical chemical chemical

compound

chemical combination of elements

heterogeneous

composed of dissimilar parts which can be separated easily

element

consists of only one substance

Which of the following physical properties would tell you about an element's mass per unit volume ratio? hardness boiling point crystalline shape density all of the above

density

The process of passing electricity through water to chemically separate it into hydrogen and oxygen is called what?

electrolysis

A substance which is made up of identical atoms is a(n):

element

NaCl: phenol (C6H6O): C2H6: . Ca3(PO4)2: formaldehyde (CH20): MgCO3: vitamin D2 (C27H40O): mercury sulfate (HgS): butane (C4H10): sand (SiO2): water (H2O):

inorganic organic organic inorganic organic inorganic organic inorganic organic inorganic inorganic

An atom: is the smallest whole unit of matter can form one or more elements is the smallest whole unit of matter with the properties of a specific element all of the above

is the smallest whole unit of matter with the properties of a specific element

As a substance changes phase from gas to liquid to solid:

its density generally increases

Pb

lead

fluorite

4

platinum

4.5

apatite

5

Which of the following items represents a chemical change? burning melting evaporation freezing

burning

Select all the items that are related to compounds. chemical bonding physical change maintain original physical properties new physical properties mixture of 2 or more elements

chemical bonding new physical properties

Fog is an example of a

colloid

Pure sugar is an example of a(n):

compound

Cu: HCl: CCl4: Co: HI: CH4:

element compound compound element compound compound

A solution which contains maximum solute at a given temperature is

saturated

chemical change

the starting materials completely lose their properties to form new substances

Which of the following was not a goal of the alchemists? to change lead into gold to discover a means to prolong life to discover new ways to use electricity to discover a universal cure for disease

to discover new ways to use electricity

talc

1

diamond

10

gypsum, tellurium

2

galena

2.5

copper, gold, silver

2.5 - 3

barite

3 - 3.5

arsenic

3.5

feldspar, magnetite

6

pyrite

6-6.5

quartz

7

topaz

8

corundum

9

A chemical reaction occurs when a solution is formed.

False

A mixture of uneven distribution and easy separation is called homogeneous.

False

A solution which contains maximum solute at a given temperature is supersaturated.

False

Colloidal particles will eventually settle out.

False

Colloids are true solutions.

False

CuSO4 is an example of a chemical element.

False

The components of a true solution blend to form new properties.

False

The most abundant gas in the atmosphere is oxygen.

False

The particles of a suspension are dissolved into the solvent.

False

When substances are formed that are different from the starting substances, a physical change has occurred.

False

Solid-in-liquid

Gelatin

Gas-in-solid

Marshmallow

Liquid-in-liquid (emulsion)

Milk

What is the most abundant gas in our atmosphere?

Nitrogen

Can colloidal suspensions be separated out by filtration?

No

melting ice: souring of milk: digesting food: evaporating water:

Physical Chemical Chemical Physical

K

Potassium

All atoms of the same element have the same number of:

Protons

Ag

Silver

Solid-in-gas

Smoke

The softest and hardest minerals are:

Talc, diamond

A change that occurs when a solid melts or a liquid freezes is an example of a phase change.

True

All the nonmetals have some similar physical properties.

True

Each element possesses unique chemical and physical properties.

True

Hardness may be defined as the resistance of a material to scratching.

True

Iron filings can be separated from a mixture with sulfur by using a magnet.

True

The components of a mixture maintain their original properties.

True

The temperature at which a substance boils is an example of a physical property.

True

A colloid can be detected by using the _____ effect.

Tyndall

The scattering of light by a colloidal suspension is called the

Tyndall effect

U

Uranium

Gas-in-liquid (foam)

Whipped cream

physical change

a change in shape, size, or physical characteristics but remaining same substance

Which is not a physical property?

ability to combine with oxygen

alchemy

an ancient study or art which attempted to combine science and philosophy to solve worldly problems

Ar

argon

The smallest unit that can exist as an element and still have the properties of that element is a(n):

atom

A mixture of uneven distribution and easy separation is called:

heterogeneous

A mixture of uneven distribution and easy separation is:

heterogeneous

Classify each of the following mixtures as homogeneous or heterogeneous: a mixture of oil and water: air: cereal in milk: a glass of tea:

heterogeneous homogeneous heterogeneous homogeneous

The two main classes of mixtures are __________ and __________

homogeneous, heterogeneous

table salt (NaCl): TNT (C7H5N3O9): glucose (C6H12O6): 2, 4-D (C3H6O3Cl2): limestone (CaCO₃): water (H₂O):

inorganic organic organic organic inorganic inorganic

An aerosol is a colloidal ________ suspended in a ________

liquid, gas

Using your knowledge of symbols, determine which compound listed must contain both copper and oxygen. glucose, C6H12O6 chalcopyrite, CuFeS2 malachite, Cu2CO3(OH)2 calcite, CaCO3

malachite, Cu2CO3(OH)2

Which is the correct definition of density?

mass/density

Hg

mercury

Inorganic compounds which are found in the earth are called:

minerals

colloid

mixture in which the suspended particles are too small to be seen with the naked eye

suspension

mixture that separates into individual components with time

homogeneous

not easily separated into individual components

A classification of matter which stipulates that the compound must contain carbon is called

organic

Choose the properties that are characteristic of true solutions. Select as many as apply. particles are suspended indefinitely particles are dissolved particles are larger than 10-8 cm light beam passes through invisibly

particles are dissolved light beam passes through invisibly

nonmetals compound chemical combination of elements

poor conductors of electricity

The disturbance of a supersaturated solution will cause:

precipitation

atom

smallest unit of an element

Na

sodium

The substance which is dissolved in a solution is called a:

solute

The substance which does the dissolving in a solution is called the

solvent

Which of the following examples represents a physical change? sugar dissolves in coffee iron rusts gasoline burns in an engine a candle burns

sugar dissolves in coffee

A mixture in which the particles eventually settle out is called a:

suspension

Dust in the atmosphere represents:

suspension

metal

the group of elements that are good conductors of electricity and heat

mixture

two or more substances dispersed in one another but each retaining their own identity

If more solute can be dissolved in a solvent, the solution is

unsaturated

Liquid-in-gas

(aerosol) Fog

calcite

3