Chapter 1 Flashcards
(172 cards)
1
Q
What is chemistry?
A
The study of matter, its properties, and the changes it undergoes.
2
Q
True or False: Chemistry is only concerned with substances that are visible to the naked eye.
A
False
3
Q
Fill in the blank: The smallest unit of an element that maintains the properties of that element is called a __________.
A
atom
4
Q
What are the two main branches of chemistry?
A
Organic chemistry and inorganic chemistry.
5
Q
Multiple Choice: Which of the following is NOT a state of matter? A) Solid B) Liquid C) Gas D) Plasma E) Energy
A
E) Energy
6
Q
What is the basic unit of measurement in the metric system for mass?
A
Gram
7
Q
True or False: A chemical change results in the formation of a new substance.
A
True
8
Q
Define ‘element’.
A
A substance that cannot be broken down into simpler substances by chemical means.
9
Q
What is a compound?
A
A substance formed when two or more elements chemically bond together.
all made up of molecule (smallest unit of compound retains retain chemical characteristics) or ions
10
Q
Fill in the blank: The __________ is a measure of the amount of matter in an object.
A
mass
11
Q
Multiple Choice: Which of the following is an example of a physical change? A) Burning wood B) Rusting iron C) Melting ice D) Baking a cake
A
C) Melting ice
12
Q
What is the difference between an atom and a molecule?
A
An atom is the smallest unit of an element (has all properties of the element), while a molecule is a group of two or more atoms bonded together.
13
Q
True or False: A mixture has a fixed composition.
A
False
14
Q
What is the law of conservation of mass?
A
Mass is neither created nor destroyed in a chemical reaction.
15
Q
Fill in the blank: The __________ scale measures the acidity or basicity of a solution.
A
pH
16
Q
Multiple Choice: Which of the following is a homogeneous mixture? A) Salad B) Air C) Soil D) Oil and water
A
B) Air
17
Q
What is an isotope?
A
Atoms of the same element that have different numbers of neutrons.
18
Q
True or False: All elements are found on the periodic table.
A
True
19
Q
Define ‘chemical reaction’.
A
A process that leads to the transformation of one set of chemical substances to another.
20
Q
What does the term ‘solvent’ refer to?
A
The substance that dissolves a solute, resulting in a solution.
21
Q
Fill in the blank: The __________ is a chart that organizes all known elements by their atomic number.
A
periodic table
22
Q
Multiple Choice: Which particle has a negative charge? A) Proton B) Neutron C) Electron D) Nucleus
A
C) Electron
23
Q
What is the difference between an ionic bond and a covalent bond?
A
An ionic bond is formed through the transfer of electrons, while a covalent bond is formed by the sharing of electrons.
24
Q
True or False: The atomic number of an element is the number of protons in its nucleus.
A
True
25
What is a chemical formula?
represents a substance, by using symbols for elements and #s for the ratio of atoms
26
Fill in the blank: A __________ is a pure substance made of two or more different elements that are chemically combined.
compound
27
Multiple Choice: Which of the following describes a gas? A) Has a definite shape B) Has a definite volume C) Takes the shape of its container D) Has a fixed arrangement of particles
C) Takes the shape of its container
28
What is the principle of atomic theory?
All matter is composed of atoms, which are indivisible and indestructible particles.
29
True or False: Solutions are always liquids.
False
30
What is the role of a catalyst in a chemical reaction?
To speed up the reaction without being consumed in the process.
31
Fill in the blank: A __________ mixture has a uniform composition throughout.
homogeneous
32
Multiple Choice: Which of the following is an example of a chemical property? A) Color B) Melting point C) Flammability D) Density
C) Flammability
33
Define 'mass number'.
The total number of protons and neutrons in an atom's nucleus.
34
What is the significance of the periodic table?
It organizes elements based on their atomic number and properties, allowing for predictions about their behavior.
35
True or False: An element can exist in multiple forms known as allotropes.
True
36
What does 'dissolution' refer to in chemistry?
The process of dissolving a solute in a solvent.
37
Fill in the blank: A __________ is a combination of two or more substances that retains its individual properties.
mixture
38
Multiple Choice: What is the primary component of air? A) Oxygen B) Nitrogen C) Carbon Dioxide D) Argon
B) Nitrogen
39
What is a physical property?
A characteristic of a substance that can be observed or measured without changing its identity.
40
True or False: All chemical changes are reversible.
False
41
What is the purpose of a chemical equation?
To represent a chemical reaction using symbols and formulas.
42
Fill in the blank: The __________ is the region around the nucleus where electrons are likely to be found.
electron cloud
43
Multiple Choice: Which of the following is a characteristic of metals? A) Poor conductors of heat B) Brittle C) Malleable D) Dull appearance
C) Malleable
44
What is the difference between a physical change and a chemical change?
A physical change affects the form of a substance, while a chemical change alters its composition.
45
True or False: Ionic compounds generally have high melting and boiling points.
True
46
What is the significance of Avogadro's number?
It represents the number of particles in one mole of a substance, approximately 6.022 x 10^23.
47
Fill in the blank: The __________ describes the arrangement of electrons in an atom.
electron configuration
48
Multiple Choice: Which of the following represents a chemical change? A) Ice melting B) Sugar dissolving C) Iron rusting D) Water boiling
C) Iron rusting
49
What is the role of electrons in chemical bonding?
Electrons are involved in the formation of bonds between atoms.
50
True or False: The pH scale ranges from 0 to 14.
True
51
What is a solute?
The substance that is dissolved in a solution.
52
Fill in the blank: __________ are substances that can donate protons (H+) in a chemical reaction.
Acids
53
Multiple Choice: Which of the following best describes a liquid? A) Definite shape and volume B) Definite volume but takes the shape of its container C) No definite shape or volume D) Fixed arrangement of particles
B) Definite volume but takes the shape of its container
54
What is a property of noble gases?
They are generally unreactive due to having a full valence shell.
55
True or False: Chemical formulas can represent both ionic and covalent compounds.
True
56
What is the difference between a saturated and unsaturated solution?
A saturated solution contains the maximum amount of solute that can dissolve, while an unsaturated solution can dissolve more solute.
57
Fill in the blank: __________ are substances that can accept protons (H+) in a chemical reaction.
Bases
## Footnote
Acids will donate(only donate H when base is not polarize) and Bases will accept
58
Fill in the blank: Chemistry is the study of _______.
Matter
59
What is defined as anything that occupies space and has mass?
Matter
60
What is the measure of the amount of matter that an object contains?
Mass
61
What are the two types of changes that matter can undergo?
* Physical Changes
* Chemical Changes
62
What does the scientific method include?
* Experiment
* Hypothesis
* Theory
* Observation
* Law
63
What is chemistry?
Chemistry is the science that studies the properties and interactions of matter.
64
Define matter.
Anything that occupies space and has mass.
65
What is mass?
Measure of the amount of matter that an object contains.
66
What are the steps of the scientific method?
1. Observation
2. Hypothesis
3. Experiment
4. Theory
5. Law
67
Define hypothesis.
A tentative explanation or prediction based on experimental observations.
68
What is a scientific law?
A concise verbal or mathematical statement of a behavior or relation that seems always to be the same under the same conditions.
69
What is a theory?
A well-tested, unifying principle that explains a body of facts and the laws based on them.
70
What are qualitative observations?
Observations that do not involve numbers and include descriptions like color and appearance.
71
What are quantitative observations?
Observations that involve measurable attributes and express numbers with units.
72
What principles should experimental results uphold?
1. Reproducibility
2. Sufficient detail for reproduction
3. Reasonable and unbiased conclusions
4. Credit where it is due
73
What are the goals of green chemistry?
1. Prevent waste
2. Maximize materials
3. Reduce toxicity
4. Minimize energy requirements
5. Use renewable materials
6. Minimize environmental persistence
7. Minimize risks
74
What does kinetic-molecular theory explain?
It explains the behavior of gases in terms of particles in motion.
75
What are the three states of matter?
* Solid
* Liquid
* Gas
76
What are the characteristic of solids?
Definite shape, fixed volume, lowest kinetic energy.
77
What are the characteristics of liquids.
No fixed shape, intermediate kinetic energy.
78
What are the characteristics of gases.
Expand to fill their container, highest kinetic energy.
79
What is a homogeneous mixture?
A mixture consisting of two or more substances in the same phase with uniform composition.
80
What is a heterogeneous mixture?
A mixture that does not have uniform composition and components are easily distinguishable.
81
How can mixtures be separated?
By physical properties such as density, boiling point, or state of matter.
82
What is a pure substance?
A substance with well-defined physical and chemical properties.
83
What are the two classifications of pure substances?
* Elements
* Compounds
84
What is an element?
A substance that cannot be converted to a simpler form by a chemical reaction.
85
What is a compound?
A combination of two or more elements in a definite, reproducible way.
86
Which state of water has the highest kinetic energy?
Steam at 115 °C.
87
What is the symbol for potassium?
K
88
Which of the following is NOT an element: hydrogen, lithium, iron, water, silver?
Water
89
What is the law of definite proportions?
A chemical compound always contains its component elements in fixed ratio by mass.
90
What is a chemical compound?
A substance composed of two or more atoms.
91
What is a molecule?
The smallest unit of a compound that retains its chemical characteristics.
92
What are physical properties?
Characteristics that can be evaluated without changing the composition of the material.
93
List some examples of physical properties.
* Color
* Odor
* Density
* Melting point
* Thermal conductivity
* Volume
* Hardness
94
What is the difference between extensive and intensive properties?
**Extensive properties ** (mass) d*epend on the amount of substance;*
** intensive properties** (density) *do not.*
95
What is a chemical property?
A characteristic that results in a change in the composition of a material.
96
Provide an example of a chemical reaction.
Wood + O2 → CO2 + water + heat
97
What results in a change in the composition of a material?
Chemical properties
| Wood + o2 --> triangle--> CO2 + H2o + heat
## Footnote
Chemical properties explain how one substance acts in the presence of another.
98
What is a chemical reaction?
How the change occurs
## Footnote
It describes the process of reactants transforming into products.
99
What is a chemical property of wood?
Its ability to burn (combustion)
| chemical reactions
## Footnote
This is an example of a chemical change.
100
What are reactants and products in a chemical reaction?
Reactants are the starting materials, and products are the substances formed.
## Footnote
For example: Wood + O2 → CO2 + water + heat.
101
What is the smallest unit of an element?
Atom
## Footnote
An atom has all the properties of an element.
102
What is a molecule?
The smallest unit of a pure substance that may contain more than one atom and element
## Footnote
Molecules exhibit all the properties of that substance.
103
What does a molecular formula represent?
The composition of molecules
## Footnote
Example: H2O for water, C8H10N4O2 for caffeine.
104
Which polymer floats on water?
Polypropylene
## Footnote
A terephthalate polymer from a soda bottle sinks.
105
Which property of matter is NOT temperature dependent?
Mass
## Footnote
Other properties such as volume, physical state, density, and solubility are temperature dependent.
106
What is a physical change?
A change that does not entail any change in chemical composition
## Footnote
Examples include melting iron or ice.
107
What is a chemical change?
Involves a change in chemical composition
## Footnote
Examples include burning magnesium or iron rusting.
108
What does chromatography do?
Separates components of a mixture without changing them
## Footnote
**This is an example of a physical change.**
109
Which of the following is NOT a physical change?
Burning a piece of paper
## Footnote
**This is a chemical change.**
110
What are the two types of energy?
Kinetic and Potential
## Footnote
**Kinetic energy is associated with motion, while potential energy is related to an object's position.**
111
What is kinetic energy?
Energy associated with motion
## Footnote
Includes thermal energy, the motion of macroscopic objects, and electrical energy.
112
What is potential energy?
Energy resulting from an object's position
## Footnote
Includes gravitational energy, energy stored in springs, and chemical energy, charges or partially charged particles (electrically charged)
113
What type of observations are qualitative?
Observations that describe changes in color and physical state
## Footnote
Opposite of quantitative measurements, which involve numbers.
114
What is the SI unit for length?
Meter (m)
## Footnote
Other SI units include kilogram for mass and seconds for time.
115
What is the conversion from Celsius to Kelvin?
T(K) = t(°C) + 273.15
## Footnote
Example: Body temperature in Kelvin is 310 K.
116
What is the SI unit for energy?
Joule (J)
## Footnote
1 J = kg × m²/s².
117
What is the relationship between calories and joules?
1 cal = 4.184 J
## Footnote
A kilocalorie (kcal) is often written as Cal, where 1 Cal = 1000 cal.
118
What is the base unit of mass in the metric system?
Gram (g)
## Footnote
1 kg = 1000 g.
119
What is dimensional analysis?
A method using conversion factors to change units
## Footnote
Example: 1 inch = 2.54 cm.
120
What is the SI unit of volume commonly used by chemists?
Liter (L) or milliliter (mL)
## Footnote
The defined unit of volume in SI is the cubic meter (m³).
121
What is the order of increasing length for 215 mm, 9 cm, 2.3 m, and 0.125 m?
9 cm < 0.125 m < 215 mm < 2.3 m
## Footnote
This requires conversion of all measurements to the same unit.
122
What is the density formula?
Density (g/mL) = mass (g) / volume (mL)
## Footnote
This formula is used to calculate the density of a substance.
123
What is the density of copper (Cu)?
8.96 g/cm3
124
What is the density of magnesium (Mg)?
1.74 g/cm3
125
What is the density of iron (Fe)?
7.87 g/cm3
126
What is the density of silver (Ag)?
10.5 g/cm3
127
What is the density of aluminum (Al)?
2.70 g/cm3
128
What is the density of lead (Pb)?
11.3 g/cm3
129
What does precision refer to in measurements?
How well measurements agree with one another
130
What does accuracy refer to in measurements?
How close a measurement is to the true value
131
True or False: A precise measurement can be inaccurate.
True
132
What is the formula for calculating percent error?
(experimental - known / know value) x 100%
133
What are significant figures?
The number of digits expressed in a numerical value that reflect the exactness or the digits in a measured quantity that were observed with the measuring device
134
Fill in the blank: All ________ numbers are significant.
non-zero
135
What is the rule for zeros between non-zero numbers?
All zeros between non-zero numbers are significant
136
Are leading zeros significant?
No, leading zeros are NEVER significant
137
When are trailing zeros considered significant?
Only if a decimal point is part of the number
138
How many significant figures are in the number 1256?
4 sf
139
How many significant figures are in the number 1056007?
7 sf
140
How many significant figures are in the number 0.000345?
3 sf
141
How many significant figures are in the number 0.00046909?
5 sf
142
How many significant figures are in the number 1780?
3 sf
143
How many significant figures are in the number 770.0?
4 sf
144
How many significant figures are in the number 0.08040?
4 sf
145
When performing combined operations, what must be determined?
The correct number of significant figures must be determined by examination of each step
146
In addition and subtraction calculations, how should results be reported?
To the fewest number of decimal places
147
In multiplication and division calculations, how should results be reported?
To the fewest number of significant figures
148
What is the total mass of three rock samples weighing 13.213 g, 243.87 g, and 0.1364 g with the correct number of digits?
257.22 g
149
What is the volume reading of the solution in the burette?
15.15 mL
150
What is the typical daily insulin dose for an individual weighing 176 lb, given in units?
16 U
151
What is the mass % of gold in a 22.5 carat ring?
93.8%
152
By which 3 Physical Methods can mixtures be separated?
density, boiling point, or states of matter.
153
Can Molecules be broken down
yes
154
what process are molecules broken down
through a process called chemical decompisition
155
what are molecules made up of?
two or more atoms bonded together
156
How many recorded elements are there
118
157
what are ionic compounds described by
formula unit
158
what are molecules described by a molecular formula
molecular formula???
| check pp
159
a f(x) of intermolecular forces are
physical properties
160
What are physical properties affected by
temperature (MOLECULAR MOTION)
## Footnote
basically density of water changes with temperature
ice has low density, and water at 100 degrees has higher density.
161
scientific model helps
visualize atom and molecules
162
molecular formula of caffeine
C_8 H_10 N_4 O_2
163
# q
chemical change
changes composition/ structure
| magnesium burns in air --> magnesium oxide
164
Electrolysis
water changes to hydrogen and oxygen
| chemical change
165
converting celsius to F
F-32 x 5/9
166
Body Temp equation to Kalvin.
37 c + 273 = 310 k
167
precision
how well measurements agree with one another
168
accuracy
ow close a measurement is to the true value
169
experimental error
* instrumental error
* human error
170
error =
experimentally determined value - accepted value
171
% error =
(error in measurement/accepted value) x 100
172
