5 Flashcards
(104 cards)
1
Q
What is a subatomic particle?
A
A particle smaller than an atom.
2
Q
What are the three main types of subatomic particles?
A
Protons, neutrons, and electrons.
3
Q
What is the charge of a proton?
A
Positive.
4
Q
Which subatomic particle plays a key role in chemical bonding?
A
Electron.
5
Q
What is the relationship between energy and the distance of an electron from the nucleus?
A
Electrons farther from the nucleus have higher energy.
6
Q
What is the term for a particle smaller than an atom but larger than a subatomic particle?
A
Elementary particle.
7
Q
What does the term ‘inert’ mean?
A
Having little or no ability to react chemically
8
Q
True or False: Inert substances are chemically reactive.
A
False
9
Q
Fill in the blank: Inert substances have _______ ability to react chemically.
A
little or no
10
Q
What is an example of an inert gas?
A
Argon
11
Q
What is the purpose of using inert gases in welding?
A
To prevent oxidation of the weld area
12
Q
Which of the following is an example of an inert material? A) Oxygen B) Helium C) Hydrogen D) Chlorine
A
B) Helium
13
Q
What is the main characteristic of inert substances in chemical reactions?
A
They do not participate in the reaction
14
Q
Inert gases are often used in packaging of food products to prevent ________.
A
spoilage
15
Q
What type of atmosphere do inert gases create in controlled environments?
A
Stable
16
Q
True or False: Inert gases are commonly used in fire suppression systems.
A
True
17
Q
What is the main advantage of using inert gases in fire suppression?
A
They do not react with the fire
18
Q
Fill in the blank: Inert gases have a low _______ potential.
A
reactivity
19
Q
Which of the following is NOT an inert gas? A) Neon B) Nitrogen C) Oxygen D) Krypton
A
C) Oxygen
20
Q
What is the primary purpose of using inert gases in the semiconductor industry?
A
To protect sensitive materials from contamination
21
Q
Inert substances are commonly used as _______ in chemical reactions.
A
catalysts
22
Q
Which industry commonly uses inert gases in heat treatment processes? A) Automotive B) Aerospace C) Electronics D) Construction
A
A) Automotive
23
Q
What is the role of inert gases in heat treatment processes?
A
To create an oxygen-free environment for heating metals
24
Q
True or False: Inert gases have no effect on the physical properties of materials.
A
True
25
Which of the following is an example of an inert material used in construction? A) Concrete B) Steel C) Aluminum D) Titanium
A) Concrete
26
What is the primary reason for using inert gases in arc welding?
To shield the weld from atmospheric contamination
27
True or False: Inert gases are colorless and odorless.
True
28
Fill in the blank: Inert gases are _______ to human health when inhaled in moderate amounts.
not harmful
29
What is the significance of using inert gases in the oil and gas industry?
To prevent explosions and fires during drilling and production processes
30
Which of the following is a characteristic of inert gases? A) Highly reactive B) Flammable C) Non-toxic D) Corrosive
C) Non-toxic
31
What is the primary benefit of using inert gases in the pharmaceutical industry?
To prevent contamination and degradation of sensitive drugs
32
What is a buffer?
A buffer is a solution that resists changes in pH when small amounts of acid or base are added.
33
True or False: Buffers are only effective in a narrow pH range.
True
34
What is the equation for the Henderson-Hasselbalch equation?
pH = pKa + log([A-]/[HA])
35
What are the two components of a buffer solution?
A weak acid and its conjugate base
36
Fill in the blank: A buffer solution is most effective when the concentration of the ________ and ________ are approximately equal.
acid, base
37
What happens to the pH of a buffer solution when a small amount of acid is added?
The pH remains relatively constant
38
What is the main function of a buffer in biological systems?
To maintain a stable pH for enzymatic reactions
39
What is the pH range where most buffers are effective?
Within one pH unit of the pKa of the weak acid component
40
How does a buffer resist changes in pH?
By neutralizing added acid or base through the reversible reaction of the weak acid and its conjugate base
41
What is the purpose of a buffer in laboratory experiments?
To maintain a constant pH for accurate and reproducible results
42
Which type of buffer system is more effective at a higher concentration: weak acid or weak base?
Weak acid
43
What is the pKa value of a buffer solution?
The pH at which the weak acid and its conjugate base are present in equal amounts
44
How does temperature affect the effectiveness of a buffer solution?
Higher temperatures can decrease the effectiveness of a buffer solution
45
What is the relationship between buffer capacity and the concentration of the buffer components?
Higher concentrations of buffer components result in higher buffer capacity
46
In a buffer solution, what happens to the pH if a strong acid is added?
The pH decreases slightly due to the neutralization of the weak base component
47
What is the buffering capacity of a buffer solution?
The amount of acid or base that can be added to a buffer without causing a significant change in pH
48
How do you calculate the pH of a buffer solution?
Using the Henderson-Hasselbalch equation
49
What is the role of a buffer in the human body?
To maintain the pH of blood and other bodily fluids within a narrow range
50
What is the pH of a buffer solution at the pKa of the weak acid component?
Equal to the pKa value
51
What is the effect of diluting a buffer solution on its buffering capacity?
Dilution decreases the buffering capacity
52
What is the ideal pH range for most biological reactions?
Around neutral pH (pH 7)
53
What is the significance of a buffer having a high buffer capacity?
It can resist larger changes in pH when acid or base is added
54
What happens to the pH of a buffer solution when a small amount of base is added?
The pH remains relatively constant
55
Why is it important to use a buffer in biochemical experiments?
To ensure that the pH remains stable for enzyme activity
56
What are isomers?
Isomers are molecules that have the same molecular formula but different structural formulas.
57
True or False: Isomers have different physical and chemical properties.
True
58
What are the two main types of isomers?
Structural isomers and stereoisomers.
59
Fill in the blank: Isomers have the same ________ but different arrangements of atoms.
molecular formula
60
What are structural isomers?
Isomers that have the same molecular formula but different connectivity of atoms.
61
True or False: Structural isomers have the same physical and chemical properties.
False
62
What are stereoisomers?
Isomers that have the same molecular formula and connectivity of atoms but differ in spatial arrangement.
63
Fill in the blank: Stereoisomers can be further divided into ________ and ________ isomers.
geometric; optical
64
What is a geometric isomer?
Stereoisomers that differ in the arrangement of groups around a double bond or ring.
65
True or False: Geometric isomers have different physical and chemical properties.
True
66
What is an optical isomer?
Stereoisomers that are non-superimposable mirror images of each other.
67
Fill in the blank: Optical isomers are also known as ________ isomers.
enantiomeric
68
How many stereocenters does a molecule need to have optical isomers?
At least one stereocenter.
69
True or False: Optical isomers rotate plane-polarized light in opposite directions.
True
70
What is a meso compound?
A molecule that has chiral centers but is optically inactive due to internal symmetry.
71
Fill in the blank: Meso compounds have an ________ plane of symmetry.
internal
72
How many stereocenters does a molecule need to have geometric isomers?
At least one stereocenter.
73
True or False: Geometric isomers can occur in molecules with double bonds or rings.
True
74
What is tautomerism?
A type of isomerism where a molecule exists in equilibrium between two structural isomers.
75
Fill in the blank: Tautomerism involves the movement of a ________ from one position to another.
hydrogen atom
76
True or False: Tautomerism results in different functional groups in the isomers.
True
77
What is conformational isomerism?
Isomerism that arises from the rotation of single bonds.
78
Fill in the blank: Conformational isomerism does not involve changes in ________.
connectivity
79
True or False: Conformational isomers have different physical properties.
False
80
What is regioisomerism?
Isomerism where the isomers differ in the placement of functional groups.
81
What is the valence shell?
The outermost shell of an atom that contains valence electrons.
82
How many electrons can the valence shell hold?
The valence shell can hold up to 8 electrons.
83
True or False: The number of electrons in the valence shell determines the chemical properties of an element.
True
84
What is the significance of the valence shell in chemical bonding?
The valence shell determines how an atom will interact with other atoms to form chemical bonds.
85
Which group of elements has a completely filled valence shell?
Noble gases
86
What is the octet rule?
Atoms tend to gain, lose, or share electrons to achieve a full outer shell of 8 electrons.
87
How many valence electrons does an atom of oxygen have?
6
88
Fill in the blank: The _______ shell is involved in chemical reactions.
valence
89
What happens to the reactivity of elements as you move from left to right across a period on the periodic table?
Reactivity decreases
90
Why do elements in the same group on the periodic table have similar chemical properties?
Because they have the same number of valence electrons.
91
Which element has 4 valence electrons?
Carbon
92
What is the charge of an atom that has lost 2 electrons from its valence shell?
2+
93
How many valence electrons does an atom of sodium have?
1
94
What type of elements tend to lose electrons to achieve a full valence shell?
Metals
95
What is the electron configuration of an atom with a full valence shell?
Stable
96
Which element has 7 valence electrons?
Chlorine
97
True or False: Atoms with a full valence shell are less likely to form chemical bonds.
True
98
What is the term for atoms sharing electrons to achieve a full valence shell?
Covalent bonding
99
Which element has 3 valence electrons?
Aluminum
100
What is the name of the group of elements that have partially filled valence shells?
Transition metals
101
What is the charge of an atom that has gained 3 electrons in its valence shell?
3-
102
How many valence electrons does an atom of nitrogen have?
5
103
Fill in the blank: The _______ electrons are involved in chemical bonding.
valence
104
What is the term for the outermost electrons in an atom?
Valence electrons
