Acids and Bases

Question 1

Lavoisier theory

Answer 1

• acidity caused by presence of oxygen- false

- created word oxygen

Question 2

Arrhenius theory

Answer 2

• acid- dissociates to form H+ ions
• bases- dissociate to form OH- ions
• dissociate= dissolves in water

Question 3

Lowry and Bronsted theory

Answer 3

• acid- substance that donates proton (H+) to another species
• base- accepts protons from other species
• allowed gaseous NH3 to be a base

Question 4

What did the Lowry and Bronsted theory allow for NH3?

Answer 4

to be classified as a base

Question 5

What to theories do we currently use?

Answer 5

• Arrhenius theory

- Lowry and Bronsted theory

Question 6

What is a monoprotic acid? Give 2 examples

Answer 6

• acid that only donates 1 mole of protons per mole of acid

- ex- HCl, HNO3

Question 7

What is a diprotic acid? Give 1 example.

Answer 7

• acid that donates 2 moles of protons per mole of acid

- ex- H2SO4

Question 8

What is a triprotic acid? Give an example.

Answer 8

• acid that donates 3 moles of protons per mole of acid

- H3PO4

Question 9

Conjugate acid

Answer 9

species formed from a Broasted-Lowry base by the addition of proton.

Question 10

Conjugate Base

Answer 10

species formed from a Broasted-Lowry acid by the loss of a proton.

Question 11

What does the acidity of a solution depend on?

Answer 11

the concentration of H+ ions

Question 12

What equation is used to find the pH of a solution?

Answer 12

-log10=[H+]

Question 13

pH values are given to __ decimal places

Answer 13

2

Question 14

What does the strength of acid refer to?

Answer 14

the pH, not the concentration

Question 15

What is a strong acid?

Answer 15

• low pH (0 or 1)
• high concentration of H+
• acid fully dissociated into its ions

Question 16

What is a weak acid?

Answer 16

• high pH (but less than 7)
• concentration of H+ is lower than those in strong acid
• acid not fully dissociated into its ions

Question 17

What equation is used to calculate concentration of H+?

Answer 17

10^-pH

Question 18

What is pH on a scale of?

Answer 18

1 to 14

Question 19

3 ways to measure pH

Answer 19

• pH meter
• universal indicator solution
• universal indicator paper

Question 20

3 examples of strong acid

Answer 20

• HCl- hydrochloric acid
• HNO3- nitric acid
• H2SO4- sulfuric acid

Question 21

3 examples of weak acid

Answer 21

• CH3COOH- ethanoic acid
• H2CO3- carbonic acid
• H3PO4- phosphoric acid

Question 22

What is an alkali?

Answer 22

An alkali is a soluble base

Question 23

What are acid-base indicators?

Answer 23

chemical detectors that change color according to the concentration of H+ ions

Question 24

State all indicators.

Answer 24

• methyl orange
• phenolphthalein
• litmus

Question 25

How can you measure ph?

Answer 25

• methyl orange
• phenolphthalein
• litmus
• pH meter- directly reads H+ concentration
• universal indicator

Question 26

What is a strong acid?

Answer 26

• dissociates fully and exists entirely as ions in a solution
• good proton donors
• their conjugate bases are not readily able to accept a proton

Question 27

weak acid

Answer 27

• dissociates only partly
• poor proton donors
• conjugate bases are readily able to accept a proton
• equilibria lies to left in favor of reactants

Question 28

strong base

Answer 28

• ionize fully

Question 29

What is acid dissociation written with that base ionization isn’t

Answer 29

equilibria signs

Question 30

weak base

Answer 30

• ionizes partially

- equilibrium lies to left

Question 31

acid deposition

Answer 31

the process when acidic compounds in the atmosphere are deposited onto earth

Question 32

Wet acid deposition

Answer 32

rain, hail, fog, mist, dew: aqueous precipitates

Question 33

Dry acid deposition

Answer 33

particles in gases, smoke, dust

Question 34

Where does sulfur oxides come from?

Answer 34

• sulfur dioxide is produced: SO2 when combined with O2
• smelting
• burning coal and fossil fuels

Question 35

Where do nitrogen oxides come from?

Answer 35

• Nitrogen Oxide (NO) is formed when internal combustion in engines
• nitrogen and oxygen combine

Question 36

Acid deposition on plant life

Answer 36

• cause leaching- important minerals become soluble and wash away before plants absorb them
• block stomata for gas exchange
• release toxic substances

Question 37

Acid deposition on water

Answer 37

• eutrophication
• Al3+ become soluble: stop fish’s gills from working
• below 4 pH, rivers are dead

Question 38

Acid deposition on human health

Answer 38

• not direct
• long term exposure
• increase risk of asthma, bronchitis, emphysema
• irritation of eyes

Question 39

Responses to SO2 emmisions

Answer 39

1. Pre combustion methods
   - removing sulfur by crushing coal and washing with water
   - hydrodesulfurization- removes sulfur by reacting with Hydrogen, this gas is removed and converted to sulfuric acid
2. Post- combustion methods
   - Flue-gas desulfurization- SO2 neutralized by reaction with CaO and CaCO3 in chimney before released

Question 40

Responses to NOx emmisions

Answer 40

1. Catalytic converters in vehicles
   - gas passed over platinum or palladium based catalyst to neutralize product
2. Lower temperature combustion
   - recirculating NO into engine lowers temperature to reduce formation of it