EXERCISE 1 - 2

Question 1

• almost all processes containing ____ have a need for pH measurement

Answer 1

WATER

Question 2

compares the acidity or alkalinity of a solution at a given temperature

Answer 2

pH

Question 3

neutral pH

Answer 3

pH 7

Question 4

pH can only be measured if it is in ____ form

Answer 4

AQUEOUS

Question 5

pH measures the dami ng

Answer 5

H+

Question 6

neutral solution activity

Answer 6

H & OH are equal

Question 7

acidic

Answer 7

ph < 7

Question 8

acidic soln activity

Answer 8

H activity ↑ ; pH value ↓

Question 9

basic

Answer 9

pH > 7

Question 10

basic soln activity

Answer 10

OH activity ↑ ; pH value ↑

Question 11

H activity and pH is

Answer 11

inversely proportional

Question 12

the acidity and basicity of a substance can be measured in terms of

Answer 12

MOLAR CONCENTRATION

Question 13

to provide ease in expressing these values, the concentration and OH- ions are denoted as

Answer 13

pH and pOH

Question 14

the pH of a solution may be measured using

Answer 14

pH paper

Question 15

measured the pH of the solution by changing its color depending on the concentration of H and OH ions

Answer 15

pH paper

Question 16

pH paper is treated with an indicator known as

Answer 16

FLAVIN

Question 17

flavin is an ____ commonly found in red cabbages

Answer 17

ANTHOCYANIN

Question 18

flavin usually turns:

solution is acidic

Answer 18

RED

Question 19

flavin usually turns:

solution is neutral

Answer 19

GREEN

Question 20

flavin usually turns:

solution is basic

Answer 20

PURPLE

Question 22

• more accurate method than pH paper
• contains a probe that passes the electrical signals to the meter itself which interprets the electrical signals and display the results on its screen

Answer 22

pH meter

Question 23

two electrodes of ph meter

Answer 23

sensor
reference

Question 24

contains a pH 7 buffer

Answer 24

sensor electrode

Question 25

usually contains **saturated KCl solution**

Answer 25

reference electrode

Question 26

made up of **porous glass**; have both a **silver wire** covered with **silver chloride** or **calomel**

Answer 26

PROBE

Question 27

pH meter probe has a silver wire that is covered with

Answer 27

silver chloride or calomel

Question 28

* H ions are **spontaneously generated** in **pure water** by the **dissociation (ionization)** of a small percentage of water molecules * dissociation makes **equal numbers** of H and OH ions * while the OH ions can float around in solution as themselves, the H ions are transferred directly to a neighboring water molecule to form **hydronium ions**

Answer 28

AUTOIONIZATION OF WATER

Question 29

# AUTOIONIZATION OF WATER H+ spontaneously ____ to **form** H+ and OH- **equally**

Answer 29

DISSOCIATES

Question 30

the ____ of H+ causes it to **bind** to another H2O molecule, thus **forming a hydronium ion**

Answer 30

REACTIVITY

Question 31

# AUTOIONIZATION OF WATER The amount of **dissociative H+** is ____ to the amount of **H3O+ formed**.

Answer 31

EQUAL

Question 32

* **Acids** are species that **increase [H+]** * **Bases** are species that **increase [OH-]** * **Limited** in describing acidity and basicity to **dissociation** in **aqueous solution**

Answer 32

ARRHENIUS

Question 33

# ARRHENIOUS Many substances **behave** as an **acid** or **base** in ____ phase where **no solvent** is **present**

Answer 33

GASEOUS PHASE

Question 34

● **Acids** are proton **donors** - Must have a **H+** that can **dissociate** ● **Bases** are proton **acceptors** - Must have **at least one pair** of electrons to form a bond with a proton

Answer 34

BRONSTED-LOWRY

Question 35

# BRONSTED react **almost completely** with **water**

Answer 35

STRONGER ACIDS | inorganic acids

Question 36

react only **slightly** with **water**

Answer 36

WEAK ACIDS | acetic acid

Question 37

**Acid strengths** are given using what values

Answer 37

pKa

Question 38

acid **dissociation** constant

Answer 38

Ka

Question 39

gives the **exact strength** of acid in water

Answer 39

Ka acid dissociation constant

Question 40

There is an ____ relationship between **Ka** and **pKa**

Answer 40

INVERSE

Question 41

* **Acids** **accept** a pair of non-binding **electrons** * **Bases** **donate** a pair of non-binding **electrons** * Suggest that **sharing electrons** between acids and bases causes **no change** in the **oxidation** numbers of any atoms.

Answer 41

LEWIS

Question 42

Provided a way of **simplifying** the expression of [H+]

Answer 42

SORENSEN

Question 43

pH means

Answer 43

pruissance d’ hydrogen

Question 44

pruissance d’ hydrogen means

Answer 44

POWER OF HYDROGEN

Question 45

how to compute for pH & pOH

Answer 45

-log [H+] -log {OH-]

Question 46

how to compute for **[H+] [OH-]**

Answer 46

10‾pH 10‾pOH

Question 47

formula for **pKw**

Answer 47

pKa + pKb = 14 pH + pOH = 14

Question 48

* **Resist** change in pH * Most organisms, including humans, need to maintain pH within a **fairly narrow range** to survive * Consists of an **acid-base** pair, with the acid and base **differing** by the **presence** or **absence** of a **proton** (conjugate acid-base pair)

Answer 48

BUFFERS

Question 49

# BUFFERS human blood involves what **acid**

Answer 49

CARBONIC ACID **H₂CO₃**

Question 50

# BUFFER **conjugate base** of the human blood

Answer 50

BICARBONATE ION **HCO₃‾**

Question 51

Used to calculate the pH of a **buffer** system

Answer 51

HENDERSON-HASSELBALCH

Question 52

formula for **buffer**, weak **acids**

Answer 52

pH = pKa + log (salt/acid)

Question 53

formula for **buffer**, weak **bases**

Answer 53

pH = pKw - pKb + log (base/salt)