Chapter 8

Question 1

to ensure good reactivity…

Answer 1

SM’s need to be of the same phase

Question 2

how do chemists ensure good reactivity

Answer 2

since molecules inherently have different phases, chemists dissolve molecules in solvents in order for all SM’s to be of the same phase (i.e. dissolved=aqueous)

Question 3

solute

Answer 3

molecule that is being dissolved

Question 4

solvent

Answer 4

molecule that is doing the dissolving process (dissolustion)…this is often H2O(l). for us, solvents will always be liquid

Question 5

solution

Answer 5

solute and solvent create a solution

Question 6

homogenous solution

Answer 6

is a mixture that cannot be determined to be a mixture visually
EX: NaCl (aq)=NaCl in water

Question 7

heterogeneous solution

Answer 7

is a mixture that can be determined to be a mixture visually
EX: oil in water

Question 8

ion-dipole forces of attraction

Answer 8

result when an ionic solid is dissolved in H2O

• Ionics in H2O result in electrolytic solutions (ones that conduct electricity due to ion dissociation)
• molecular compounds (not ionic) can still dissolve (matching of forces of attraction) but there is NO dissociation, the molecule solute is simply surrounded by solvent
• -result in non-electrolytic solutions

Question 9

molarity

Answer 9

mols of solute/L of solution

Question 10

molality

Answer 10

mols solute/kg of solvent

Question 11

% mass

Answer 11

mass solute/total mass X100

Question 12

% volume

Answer 12

volume solute/total volume solution X100

Question 13

Aqueous reactions

Answer 13

1) acid-base reactions
2) precipitation reactions
3) redoc reactions
4) gas evolution reactions

Question 14

Acid (bronsted-lowry definition)

Answer 14

is a source of H+ (aq) in aqueous solution

Question 15

Base (bronsted-lowry definition)

Answer 15

source of hydroxide in aqueous solution (OH-; hydroxide)

Question 16

acid-base chemistry

Answer 16

H+ (acid) + OH- (base)–>H2O

-results in a neutral charge=neutralization

Question 17

titrations

Answer 17

used to quantitate concentrations of uknown solutions using quantitativereactions to ensure 100% reactivity of SM’s

Question 18

precipitation reactions

Answer 18

not all ionic solutes are soluble in H2O(l), some precipitate out from H2O(l) giving rise to precipitation reactions
-solid precipitate produced from two aqueous SM’s

Question 19

total ionic reaction

Answer 19

show all ions

Question 20

net ionic reactions

Answer 20

just show the “players”, the ones doing the chemistry, not the “spectators”

Question 21

redox reactions

Answer 21

reduction/oxidation reactions

1) identify oxidation #’s
2) write 1/2 reactions; one for oxidation and one for reduction using oxidation #’s as a guide

Question 22

reduction

Answer 22

an element is gaining e-

Question 23

oxidation

Answer 23

an element is losing e-

Question 24

oxidation numbers

Answer 24

• if an element is in its natural state its oxidation number is ZERO
• in molecules, elements will have the same oxidation number as its prefered charge (for the most part) (use go to elements to aid in the process)
• the most electropositive elements get + oxidation numbers…greater elements
• most electronegative elements get - oxidation number
• the sum of the oxidation # in a molecule must equal the charge on the molecule

Question 25

what is being reduced is also known as...

Answer 25

the oxidation agent since it is the element causing oxidation of the other element (oxidant) -pulling e-'s from another element

Question 26

what is being oxidized is also known as...

Answer 26

the reducing agent since it is the element causing reduction of the other element (reductant)