Chm 1025 Practice Exam

Front 1

There are exactly 2.54 centimeters in 1 inch. When using this conversion factor, how many significant figures are you limited to?

Back 1

infinite number of significant figures

Front 2

Trailing zeros at the end of a number, but before an implied decimal point, are ambiguous.

Back 2

true

Front 3

When the number 65.59 is rounded to contain 2 significant figures, it becomes 66.0

Back 3

false

Front 4

If you know the density of a liquid and its volume, the mass of the liquid may be calculated using the equation: m = V/d.

Back 4

faslse

Front 5

Suppose a boat engine leaks 938 milliliters of oil into a lake. The mass of this spilled oil is The oil will not mix with the lake water. Which statement is true?

Back 5

The oil will float because its density of 0.877 g/mL is less than the density of water.

Front 6

A lead ball has a mass of 55.0 grams and a density of 11.4 g/cm3. What is the volume of the ball?

Back 6

4.82 mL

Front 7

Given the following list of densities, which materials would float in a molten vat of lead provided that they do not themselves melt? Densities (g/mL): lead = 11.4, glass = 2.6, gold = 19.3, charcoal = 0.57, platinum = 21.4.

Back 7

glass and charcoal

Front 8

Gases are the only form of matter that is compressible.

Back 8

True

Front 9

Which state of matter has atomic spacing that is close together and indefinite shape?

Back 9

liquid

Front 10

Liquids have definite volume and indefinite shape.

Back 10

true.

Front 11

Solids have indefinite shape and volume.

Back 11

false

Front 12

Which state of matter has atomic spacing that is close together and definite shape?

Back 12

solid

Front 13

In a solid substance, the atoms or molecules oscillate and vibrate about a fixed point.

Back 13

true

Front 14

Both solids and liquids are incompressible while gases are compressible.

A gas has neither definite volume nor definite shape.

A liquid has a definite volume; but it has no definite shape.

A solid has a definite shape and a definite volume.

Back 14

all statements are true

Front 15

Which state of matter has atomic spacing that is far apart and definite shape?

Back 15

no of them

Front 16

Water is a mixture.

Back 16

false

Front 17

Which of the following items is a pure substance?

Back 17

ice, tin, sulfur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) and baking soda (sodium bicarbonate).

Front 18

Matter

Back 18

Anything that takes up space, has mass, and is made up of particles.

Front 19

Pure Substance

Back 19

A material that is composed of only one type of particle; examples of a pure substance include gold, oxygen and water.

Front 20

mixture

Back 20

A material made up of at least two different pure substances.

Front 21

Homogeneous

Back 21

A material having only one set of properties.

Front 22

Heterogeneous

Back 22

A mixture, made up of parts that retain their own properties, even if these properties are not visible to the unaided eye.

Front 23

Skim milk is a heterogeneous mixture.

Back 23

false

Front 24

examples of homogeneous mixture?

Back 24

stainless steel

Front 25

A pure substance may either be an element or a compound.

A mixture may be either homogeneous or heterogeneous.

Mixtures may be composed of two or more elements, two or more compounds, or a combination of both.

Matter may be a pure substance or it may be a mixture.

Back 25

all these statements are tru

Front 26

How would you classify salt water?

Back 26

mixture-homogeneous

Front 27

Chemical properties of a substance are those that can be observed without changing the composition of a substance.

Back 27

false

Front 28

Flammability of gasoline is a chemical property.

Back 28

true

Front 29

Physical properties are:

Back 29

those that a substance displays without changing its composition.

Front 30

In a chemical reaction, the substances present after the chemical change are called reactants.

Back 30

false

Front 31

The melting of ice is a physical change.

Back 31

true

Front 32

The corrosion of iron is a physical change

Back 32

false

Front 33

Phase changes are always physical changes.

In a chemical change, matter changes its composition.

Chemical reactions are chemical changes.

In a physical change, matter does not change its composition.

Back 33

all these statements are true.

Front 34

A chemical change occurs when matter does not change its composition

Back 34

false

Front 35

Which type of energy is associated with motion?

Back 35

kinetic

Front 36

What type of energy is associated with the burning of gasoline?

Back 36

chemical

Front 37

common unit of energy?

Back 37

joule

kilowatt-hour

calorie

Front 38

A kelvin degree is the same size as a Celsius degree.

Back 38

true

Front 39

Absolute zero is equivalent to a temperature of -273 K.

Back 39

false

Front 40

The boiling point of water is

Back 40

212 F

373 Kelvin

100 Celcius

Front 41

Which statement below accurately describes the contributions of Dalton?

Back 41

proposed the modern Atomic Theory

Front 42

Which statement below accurately describes the contributions of Thomson?

Back 42

discovered the existence of electrons

Front 43

Because atoms are neutral, the existence of a negatively charged particle implied there must be a positively charged component of an atom.

Thomson proposed that electrons were small particles held within a positively charged sphere.

The negatively charged electron is located outside the nucleus.

Back 43

discovery of electrons

Front 44

The plum pudding model proposed that negatively charged electrons were held in a sphere of positive charge.

Back 44

true

Front 45

All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements.

Atoms combine in simple, whole-number ratios to form compounds.

Each element is composed of tiny indestructible particles called atoms.

Back 45

Dalton's Atomic Theory

Front 46

Which statement reflects the results of Rutherford's gold foil experiments?

Back 46

Almost all of the alpha particles passed directly through the foil.

Front 47

J.J. Thomson discovered

Back 47

discovery of the first subatomic particle.

Front 48

Ernest Rutheford prove that

Back 48

inside an atom there is a nucleus

Front 49

The gold foil experiment proved that large regions of the atoms consisted of empty space.

Back 49

true

Front 50

An atom containing 7 protons, 8 neutrons, and 7 electrons

Back 50

is charge-neutral.

Front 51

Mendeleev is best remembered for his pioneering work on determining atomic structure.

Back 51

false

Front 52

Mendeleev's early periodic table predicted the existence of elements that had yet to be discovered.

Back 52

true

Front 53

Group 1A elements are also called:

Back 53

alkali metals.

Front 54

In the modern periodic table, elements are listed in order of increasing atomic number rather than increasing relative mass.

Back 54

true

Front 55

Metals are located on the left side of the periodic table

Back 55

true

Front 56

Group 8A elements are also called:

Back 56

noble gas

Front 57

A cation forms when an atom gains an electron.

Back 57

false

Front 58

When an atom loses an electron, the resulting particle is called

Back 58

a cation.

Front 59

Cations are positive ions and anions are negative ions.

Cations are formed when an atom loses electrons.

Anions are formed when an atom gains electrons.

Back 59

all true statements

Front 60

cations

Back 60

Cations are ions with a net positive charge.

Front 61

anions

Back 61

Anions are ions with a net negative charge