Chemistry II

Question 1

define adhesion

Answer 1

Attraction between 2 unlike molecules

Property of water allowing it to stick to other surfaces

Question 2

define cohesion

Answer 2

Property of water

attraction between 2 unlike molecules

Question 3

example of cohesion

Answer 3

water droplets forming

Question 4

example of adhesion

Answer 4

water sticking to plant/ windshield of car

Question 5

Define surface tension

Answer 5

uneven forces acting on the particles of the surface of a liquid

ability of water to resist external force

due to cohesion

Question 6

example of surface tension

Answer 6

water striders

Question 7

How do cohesion and adhesion aid plants and the movement of water

Answer 7

Cohesion- keeps water molecules together

Adhesion- allows water to stick to surface of xylem

both these properties allow and plant to pull the water up

Question 8

what is pH

Answer 8

“power of hydrogen”

A measurement/scale of how basic or acidic a solution is (based on type of ion it creates with water)

Question 9

What is an ionic bond

Answer 9

chemical bond between a metal and nonmetal

Question 10

what is an ionic bond held together by

Answer 10

electrostatic charges

Question 11

charge of cations

Answer 11

+ charge because elements lose electrons

metals form cations

Question 12

charge of anions

Answer 12

• because elements gain electrons

nonmetals form anions

Question 13

What are halogens so reactive with Alkali Metals

Answer 13

Halogen need to gain 1
Alkali need to lose 1

When mixing, they create a full valence shell, making them so reactive

Question 14

What is the difference between acids and bases when it comes to ions

Answer 14

acids are +
- presence of hydronium ions

bases are -
- presence of hydroxide ions

When averaged out, we get a neutral substance (water)

Question 15

what are pure substances

Answer 15

substances that can’t be broken down by physical means

Question 16

What types are considered pure substances

Answer 16

elements

compounds

Question 17

How can I tell difference between heterogeneous and homogeneous mixture

Answer 17

Hetero- individual parts can be seen

Homo- looks like one substance

Question 18

Give 2 examples of homogeneous mixtures

Answer 18

salt water
sugar water

Question 19

Give 2 examples of heterogeneous mixture

Answer 19

cereal
oil with vinegar

Question 20

Why is the surface tension of water so great.

Answer 20

The water molecules have to form stronger bonds with each other since one side is open

(strong cohesion makes it difficult for molecules to be broken apart)

Question 21

Where would I find atoms that form positive ions on the periodic table

Answer 21

left (metals) = positive ions

Question 22

What type of elements form negative ions

Answer 22

nonmetals

Question 23

How can a base neutralize an acid

Answer 23

of hydroxide ions from base cancels out hydronium ions of an acid, cancel out to become neutral

Question 24

What is the law of conservation of mass

Answer 24

Mass cannot be created or destroyed, it just changes forms

Question 25

How does the law of conservation of mass apply to chemical equations

Answer 25

mass and # of atoms are equal on reactants and products

Question 26

What happens in a chemical reaction

Answer 26

old chemical bonds in reactants break apart, the atoms are rearranged and form new bonds results in new physical and chemical properties

Question 27

How can you tell a chemical reaction has taken place

Answer 27

change in color bubbles precipitate change in energy (heat given off or absorbed

Question 28

endothermic

Answer 28

A reaction that the system absorbs energy from it surroundings in the form of heat

Question 29

exothermic

Answer 29

A reaction that releases energy from the system in the form of heat

Question 30

How can I determine if a clear solution is a homogeneous mixture

Answer 30

you could boil the substance to determine 2 different substances

Question 31

strong acids and bases are both

Answer 31

corrosive

Question 32

What happens to different litmus paper in the presence of acids or bases

Answer 32

red to blue (bases) blue to red (acids)

Question 33

how does lowering the volume of a liquid speed up chemical reactions

Answer 33

the particles are closer together, leading to more collisions with the appropriate energy and configuration will happen

Question 34

how does increasing the temperature of a substance lead to a faster chemical reaction

Answer 34

higher temperature means particles are moving faster faster moving particles means more energy and a greater likelihood of the reaction-causing collision

Question 35

how does breaking SA result in faster chemical reactions

Answer 35

When particles travel in packs, there surface area is very small and only the outside particles can collide By breaking up the clumps into individual pieces, the total surface area is increased and each particle has an exposed surface that can react

Question 36

How do chemical catalysts speed up chemical reactions

Answer 36

they lower the activation energy (lowering the energy required to start a reaction)

Question 37

how does increasing the concentration of a substance lead to a speed in chemical reaction

Answer 37

by increasing the number of particles in the substances, it means there are more particles of that substance in the same space. This creates an environment where more collisions can take place.

Question 38

Ionic compounds typically have what kind of melting points

Answer 38

High melting point material can withstand higher temps before transforming to a liquid state

Question 39

Why do elements in group 1 of the periodic table form +1 ions while elements in Group 17 form -1 ions

Answer 39

Group 1 are 1+ ions because when they react, they will have 1 more proton than electrons. Group 17 are 1- because when they react, they will have 1 more electron than proton