8+18 acids and bases

Question 1

what is arrhenius’ theory of acids?

Answer 1

a substance that releases H+ ions when dissolved in water

Question 2

what is arrhenius’ theory of bases?

Answer 2

a substance that releases OH- ions when dissolved in watr

Question 3

what is the bronsted-lowry theory of acids?

Answer 3

an acid is a substance that can donate a proton to another substance

Question 4

what is the bronsted-lowry theory of bases?

Answer 4

a base is a substance that can accept a proton from another substance

Question 5

what are amphiprotic species?

Answer 5

substances that can act both as a bronsted-lowry base and acid

i.e. both donate and accept a proton

Question 6

what are amphoteric substances?

Answer 6

substances that act as an acid and a base

Question 7

what is the lewis theory of acids?

Answer 7

an acid is an electron pair acceptor

Question 8

what is the lewis theory of bases?

Answer 8

a base is an electron pair donor

Question 9

label the types of acids/bases

A: can donate a proton
B: releases OH- ions when dissolved in water
C: electron pair donor

Answer 9

A: B-L acid
B: arrhenius base
C: lewis base

Question 10

lewis acids and bases form ______ bonds

Answer 10

dative

Question 11

recall transition metals: in complexes, the transition metal acts as a lewis ______ and the ligand acts as a lewis _______

Answer 11

acid, base

Question 12

in aqueous solution, acids:

taste ______
have a pH of ____ to _____
react with _____ to form salt and water
react with carbonates to form ____, ______ and _____
react with ______ to form salt and hydrogen
releases ____ when dissolved in water

Answer 12

sour
1-7
bases
salt, water, CO2
metals
H+

Question 13

alkalis are ________ bases

Answer 13

soluble

Question 14

alkalis:

taste ______
have a pH of _____ to _____
react with acids to form ____ and ____
releases ___ when dissolved in water

Answer 14

bitter
7-14
salt, water
OH-

Question 15

water can can act as both a _________ acid and base

Answer 15

bronsted lowry

Question 16

does pure water get more acidic as temperature increases?

Answer 16

yes

Question 17

is water always neutral?

Answer 17

yes!

Question 18

what is Kw?

Answer 18

the ionic product constant of water

Question 19

at 25ºC, Kw =…

Answer 19

1.00 x 10^-14

Question 20

self-ionisation of water is [exo/endo]thermic

Answer 20

endo

Question 21

what are neutral solutions?

Answer 21

solutions where [H+] = [OH-]

Question 22

the larger the pH value, the ________ the [H+]

Answer 22

smaller

Question 23

fill in the equation for pH:
14 = …

Answer 23

14 = pH + pOH

Question 24

weak acids form [strong/weak] conjugate bases

Answer 24

strong

Question 25

the weaker the base, the ________ the conjugate acid

Answer 25

stronger

Question 26

recap: the strength of an acid is dependent on its...

Answer 26

degree of dissociation

Question 27

what substances is acid deposition is caused by?

Answer 27

sulfur dioxide and nitrogen oxides

Question 28

acid deposition leads to ____ of limestone buildings

Answer 28

corrosion

Question 29

how are oxides of nitrogen produced?

Answer 29

high temperatures of internal combustion engines in cars

Question 30

what are the equations for the reaction of nitrogen oxides to form acid rain? (3)

Answer 30

2NO + O2 –> 2NO2 2NO2 + H2O –> HNO3 + HNO2 HNO2 + O2 –> 2HNO3

Question 31

how is sulfur dioxide produced?

Answer 31

1. volcanic eruptions 2. combustion of fossil fuels

Question 32

what is the equation for the formation of sulfur dioxide?

Answer 32

S + O2 –> SO2

Question 33

what is the equation for the formation of acid rain from sulfur dioxide? (3)

Answer 33

SO2 + H2O –> H2SO3 SO2 + O2 –> 2SO3 SO3 + H2O –> H2SO4

Question 34

what are two ways to deal with acid deposition?

Answer 34

1. pre-combustion removal of SO2 2. post-combustion removal of SO2

Question 35

how is SO2 removed pre-combustion?

Answer 35

- heat crude oil fractions in the presence of a catalyst to convert S –> HS2 - HS2 is removed by bubbling through an alkaline solution

Question 36

how is SO2 removed post-combustion?

Answer 36

- flue gas is passed through CaO and CaCO3 - SO2 reacts to to form harmless CaSO4

Question 37

what is Ka? (short defin.)

Answer 37

measure of the strength of a weak acid

Question 38

are Ka and Kb affected by temperature?

Answer 38

yes!

Question 39

the _____ the Ka value, the stronger the weak acid

Answer 39

larger

Question 40

the larger the pKa value, the ________ the weak acid

Answer 40

weaker

Question 41

what is the pKa equation?

Answer 41

pKa = -log10Ka

Question 42

what is the Ka equation?

Answer 42

Ka = [H3O+][A-]/[HA]

Question 43

what is the base dissociation constant? (short defin.)

Answer 43

a measure of the strength of the weak base