Module 3.3 Acids, Bases, and pH

Question 1

What are acids and bases?

Answer 1

Chemical compounds that have specific properties and a certain number of hydrogen ions (H+) when dissolved in water.

Question 2

Hydrogen atoms have

Answer 2

1 proton and 1 electron

Question 3

Hydrogen ions have

Answer 3

lost its electron. Has only 1 proton.

Question 4

Hydrogen ions are

Answer 4

positively charged

Question 5

How does dissociation happen?

Answer 5

Sometimes one of the polar covalent bonds of water pulls the electrons so far towards the oxygen that the water molecule falls apart or dissociates

Question 6

The equation for the dissociation of water is: ​

Answer 6

H2O → OH- + H+ ​

Question 7

Rarely during dissociation, H+ is

Answer 7

quickly picked up by a passing water molecule to become H3O+ aka a hydronium ion

Question 8

When a hydronium ion is made, it results in a

Answer 8

a hydroxide ion left (OH-)

Question 9

What happens during the dissociation of water?

Answer 9

Water dissociates into hydroxide ions (OH-) and hydrogen ions (H+).

Question 10

What is the chemical equation for the dissociation of water?

Answer 10

H2O → OH- + H+

Question 11

What is a hydronium ion?

Answer 11

H3O+, formed when H+ is picked up by a passing water molecule.

Question 12

How often does the hydrogen ion get picked up during dissociation?

Answer 12

1 in 1x10^7 molecules of water in neutral water

Question 13

What is the official chemical name of H+?

Answer 13

Hydrogen ion.

Question 14

How is H+ read

Answer 14

H plus

Question 15

The hydrogen atom has

Answer 15

1 proton and 1 electron

Question 16

When the electron is lost in the hydrogen ion, the only part of the hydrogen atom left is the

Answer 16

proton

Question 17

What defines an acid in biological terms?

Answer 17

A molecule that can donate H+.

Question 18

An acid increases the hydrogen ions in

Answer 18

a solution

Question 19

An acidic solution is a solution that has a

Answer 19

high concentration of H+ or hydronium ions

Question 20

What is the difference between strong acids and weak acids?

Answer 20

Strong acids completely dissociate; weak acids do not.

Question 21

Give examples of strong acids.

Answer 21

• Sulfuric acid
• Hydrochloric acid
• Nitric acid

Question 22

Give examples of weak acids.

Answer 22

• Carbonic acid
• Citric acid
• Acetic acid

Question 23

What defines a base?

Answer 23

Atoms or molecules that can accept H+.

Question 24

What is a characteristic of a basic solution?

Answer 24

Low concentration of H+ or high concentration of OH-.

Question 25

Bases decrease

Answer 25

H+ concentrations in a solution

Question 26

Weak bases do not

Answer 26

dissociate completely

Question 27

Give examples of weak bases.

Answer 27

* Ammonia (NH3)

Question 28

What defines strong bases?

Answer 28

They dissociate completely and create OH- ions that can pick up hydrogen ions indirectly.

Question 29

Strong bases dissociate

Answer 29

completely

Question 30

Give examples of strong bases.

Answer 30

* Sodium hydroxide * Sodium phosphate * Sodium carbonate

Question 31

What are some properties of acids?

Answer 31

* Taste sour * Are corrosive * Conduct electricity

Question 32

Strong acids nearly completely

Answer 32

dissociate

Question 33

Weak acids do not do what well?

Answer 33

Dissociate

Question 34

What percentage of weak acids dissociate

Answer 34

usually only 5%​

Question 35

What is the pH scale?

Answer 35

A measure of the acidity or basicity of an aqueous solution.

Question 36

Hydronium is more common in

Answer 36

acids

Question 37

The pH scale goes from

Answer 37

1 to 14

Question 38

pH stands for

Answer 38

The Power of Hydrogen or the Power of Hydronium

Question 39

Another way to look at pH is as a measure of

Answer 39

the concentration of H+ in an aqueous solution

Question 40

Neutral substances

Answer 40

are neither acidic nor basic​ (ex NaCl and distilled water)

Question 41

What is the neutral pH value?

Answer 41

7.

Question 42

The numbers on the scale range from 0 to 14 and reflect

Answer 42

the concentration of H+ and OH- in the solution

Question 43

A fluid is assigned a number according to

Answer 43

the number of H+ ions present in a liter of that fluid

Question 44

What does a lower pH number indicate?

Answer 44

Higher concentration of H+ ions and the LOWER the OH- concentration​.

Question 45

What does a higher pH number indicate?

Answer 45

Lower concentration of H+ ions and higher concentration of OH- ions.

Question 46

What is the pH of an acidic solution?

Answer 46

Below 7.

Question 47

What is the pH of a basic or alkaline solution?

Answer 47

Above 7.

Question 48

Low pH is

Answer 48

acidic. It has more H+ ions and fewer OH- ions

Question 49

High pH is

Answer 49

basic and has more OH- ions and fewer H+ ions

Question 50

The pH scale is a what kind of scale

Answer 50

logarithmic scale

Question 51

A logarithmic scale is a base

Answer 51

10

Question 52

A change of one whole pH number represents

Answer 52

a ten-fold (10X) change in the number of H+ ions

Question 53

What happens to proteins if the pH changes too much?

Answer 53

They can denature or fall apart.

Question 54

What are buffers?

Answer 54

Substances that resist sudden changes to the original pH of a solution.

Question 55

Give an example of a buffer in human blood.

Answer 55

Carbonate-bicarbonate buffer.

Question 56

What is the formula for the carbonate-bicarbonate buffer?

Answer 56

H2CO3 ↔ HCO3- + H+​

Question 57

Normal pH of blood

Answer 57

7.4

Question 58

What do buffers do when pH becomes too acidic?

Answer 58

Act like a base and accept H+ ions.

Question 59

What do buffers do when pH becomes too basic?

Answer 59

Act like an acid and accept OH- ions.

Question 60

STRONG acids and bases can

Answer 60

neutralize each other

Question 61

What is neutralization?

Answer 61

A reaction where H+ of an acid combines with OH- of a base to form water.

Question 62

What are salts?

Answer 62

Substances that dissociate into cations and anions in water, neither of which are H+ or OH-.

Question 63

How are salts formed?

Answer 63

In a neutralization reaction.

Question 64

Strong acids and strong bases react to form

Answer 64

water and a salt​. They make neutral products.

Question 65

What are electrolytes?

Answer 65

Salts dissolved in water that conduct electricity.

Question 66

Examples of electrolytes

Answer 66

Na+​ Cl-​ K+​ Ca2+​ Mg2+

Question 67

What are some functions of electrolytes?

Answer 67

* Maintaining salt/water balance * Maintaining acid/base balance * Involved with nerve function and parts of bone and teeth