Chem Lec 1 & 2 Flashcards
(134 cards)
1
Q
What is chemistry?
A
The study of matter and changes it undergoes
Chemistry encompasses various branches including organic, inorganic, physical, analytical, and biochemistry.
2
Q
Define matter.
A
Anything that has mass and occupies space
Matter exists in various states, including solid, liquid, gas, and plasma.
3
Q
What is distance measured in?
A
Meters
4
Q
What is volume measured in?
A
Liters
5
Q
What is a graduated cylinder?
A
A cylinder marked for how much fluid it contains
Used for accurately measuring the volume of liquids.
6
Q
How should you take a reading from a graduated cylinder?
A
From the bottom of the meniscus at eye level
This ensures an accurate measurement of the liquid’s volume.
7
Q
What formula is used to calculate the volume of solids?
A
Height x Width x Length
This formula applies to regular-shaped solids.
8
Q
What method is used to find the volume of irregular solids?
A
Water displacement
The volume of water displaced by the solid indicates its volume.
9
Q
What is mass is measured in?
A
Grams
10
Q
What is density?
A
Density is the amount of matter in a certain volume.
11
Q
How do you calculate density?
A
By measuring the volume and mass of an object and dividing mass by volume.
12
Q
What are the two temperature scales mentioned?
A
Celsius and Kelvin
These scales are commonly used in scientific measurements.
13
Q
What types of thermometers are mentioned?
A
Digital and liquid
Digital thermometers provide electronic readings, while liquid thermometers use liquid expansion.
14
Q
When taking temperatures, where should the thermometer bulb be placed?
A
In the middle of your liquid
This ensures accurate readings by avoiding contact with the container.
15
Q
True or False: The thermometer bulb should touch the sides or bottom of the container when taking a temperature reading.
A
False
Touching the sides or bottom can lead to inaccurate temperature measurements.
16
Q
What is the SI prefix system based on?
A
Powers of 10
The SI prefix system simplifies the conversion between different units of measurement.
17
Q
How do you convert to a smaller unit of measurement?
A
Move the decimal point to the right as many places as the difference in place value.
This method increases the numerical value of the measurement.
18
Q
How do you convert to a larger unit of measurement?
A
Move the decimal point to the left as many places as the difference in place value.
This method decreases the numerical value of the measurement.
19
Q
Fill in the blank: The SI prefix system makes it ______ to convert between units.
A
easy
20
Q
What is the freezing point of water in Celsius?
A
0°C
21
Q
What is the boiling point of water in Celsius?
A
100°C
22
Q
What temperature scale is used in the English system?
A
Fahrenheit (°F)
23
Q
What is the absolute temperature scale?
A
Kelvin (K)
24
Q
What is the relationship between Celsius and Kelvin?
A
Units of Celsius and Kelvin are equal in magnitude
25
In which system is the temperature measured in Celsius?
The Metric system
26
Fill in the blank: The freezing point of water is ______ in Celsius.
0°C
27
Fill in the blank: The boiling point of water is ______ in Celsius.
100°C
28
True or False: The unit of temperature in the SI system is Kelvin.
True
29
What is accuracy in measurement?
How close a measurement is to the true or accepted value
## Footnote
Accuracy reflects the correctness of a measurement compared to a known standard.
30
What is precision in measurement?
How closely measurements of the same thing are to one another
## Footnote
Precision indicates the consistency of repeated measurements, regardless of their closeness to the true value.
31
What are significant figures?
Includes all certain digits and the first uncertain digit
## Footnote
Significant figures are used to convey the precision of measurements.
32
What are the rules for significant figures regarding non-zero digits?
Non-zero digits are always significant
## Footnote
This principle ensures that all digits except zero contribute to the precision of a measurement.
33
Are zeros between significant digits considered significant?
Yes, any zeros between two significant digits are significant
## Footnote
This rule applies to maintain the integrity of the measurement's precision.
34
In multiplication and division, how is the number of significant figures in the answer determined?
The LEAST number of significant figures in any number of the problem determines the number of significant figures in the answer
## Footnote
This ensures that the answer reflects the precision of the least precise measurement.
35
When are trailing zeros significant?
A final zero or trailing zeros in the decimal portion ONLY are significant
## Footnote
This rule highlights the importance of decimal placement in determining precision.
36
In addition and subtraction, what should be counted for significant figures?
Count the number of significant figures in the decimal portion ONLY of each number in the problem
## Footnote
This focuses on the precision of the decimal values involved in the calculation.
37
What determines the number of significant figures in the final answer for addition and subtraction?
Your final answer may have no more significant figures to the right of the decimal than the LEAST number of significant figures in any number in the problem
## Footnote
This rule ensures the result reflects the least precise measurement in terms of decimal accuracy.
38
How can 2300 mL be expressed in scientific notation?
2.3 x 10^3 mL
39
What is the significance of using scientific notation for 2300 mL?
It clarifies the number of significant figures.
40
True or False: 2300 mL can have either 2, 3, or 4 significant figures.
True
41
What is Dimensional Analysis?
Problem solving method of chemistry that employs conversion factors
42
What does Dimensional Analysis do?
Changes one measure to another
43
What are conversion factors?
Factors used in Dimensional Analysis to convert units
44
Do all conversion factors have the same significance in terms of significant figures?
No, some have exact (infinite) sig fig while others limit sig figs
45
Provide an example of a conversion factor with infinite significant figures.
365 days/1 year
46
Provide an example of a conversion factor that limits significant figures.
1 dime/10 pennies
47
If a can of Coca-Cola contains 12 fluid ounces, what is the volume in quarts?
0.375 quarts
## Footnote
Calculation: 12 fl oz × (1 qt / 32 fl oz) = 0.375 qt
48
What is the conversion factor for quarts to fluid ounces?
1 qt = 32 fl oz
49
What is the conversion factor from centimeters to meters?
100 cm = 1 meter
50
Convert 12.00 inches to meters.
## Footnote
2.54 cm = 1 in
0.3048 meters
## Footnote
Calculation: 12.00 in * 2.54 cm/in * 1 m/100 cm = 0.3048 m
51
What is the formula for density?
Density (D) = Mass / Volume
52
What is the unit of volume in the metric system?
meter cubed (m^3)
53
What is the relationship between liters and decimeters cubed?
1 liter (L) = 1 decimeter cubed (dm3)
54
True or False: 1 mL is equal to 1 cm3.
True
55
If you have 50.00 g of ethanol, what is its volume?
63.4 cm³
## Footnote
Volume can be calculated using the formula: Volume = Mass / Density. Therefore, Volume = 50.00 g / 0.789 g/cm³.
56
What is the arrangement of particles in a solid?
Particles close together in orderly fashion
## Footnote
Solids have little freedom of motion.
57
What is the freedom of motion like in solids?
Little freedom of motion
## Footnote
Solids do not conform to the shape of their container.
58
How do particles behave in a liquid?
Particles close together but not held rigidly in position
## Footnote
This allows particles to move past one another.
59
What does a liquid do in relation to its container?
Conforms to the shape of the container
## Footnote
Liquids do not have a fixed shape.
60
Describe the arrangement of particles in a gas.
Particles randomly spread apart
## Footnote
Gases have complete freedom of movement.
61
What is the freedom of movement like in gases?
Complete freedom of movement
## Footnote
Gases assume both shape and volume of their container.
62
Fill in the blank: In a solid, particles are _______.
close together in orderly fashion
63
Fill in the blank: A liquid does not have a fixed shape but _______.
conforms to the shape of the container
64
True or False: Gases have a definite shape and volume.
False
## Footnote
Gases assume both the shape and volume of their container.
65
What are the states of matter that can be inter-converted without changing chemical composition?
solid, liquid, gas
66
What happens to matter when heat is added?
It can change from solid to liquid to gas
67
What happens to matter when heat is removed?
It can change from gas to liquid to solid
68
How is matter classified?
As a pure substance or a mixture of substances
69
Define a mixture.
Group of 2 or more substances that are physically intermingled
70
What is a key characteristic of mixtures?
They retain many properties of their components
71
Can mixtures be separated, and if so, how?
Yes, by a physical change
72
What is a homogeneous mixture?
Composition of the mixture is uniform throughout
73
Give an example of a homogeneous mixture.
Sugar dissolved in water
74
What is a heterogeneous mixture?
Composition is not uniform throughout
75
Give an example of a heterogeneous mixture.
Sugar mixed with iron filings
76
Fill in the blank: A mixture can vary in its parts by _______.
mass
77
True or False: A mixture is considered a substance.
False
78
What can pure substances be classified as?
Either an element or a compound
79
What characteristics do pure substances have?
A definite (constant) composition and distinct properties
80
What is an element?
A substance that cannot be broken down further into simpler or other pure substances by physical or chemical means
81
What does an element consist of?
Only ONE type of atom
82
What is the periodic table of elements?
A table where each element has a name and is unique because the atoms are unique
83
How do the properties of compounds compare to those of the elements from which they are formed?
The properties of compounds are ALWAYS different from the properties of the elements
84
Can an element be separated into simpler substances by chemical means?
No
85
Give examples of elements.
* Iron
* Mercury
* Oxygen
* Hydrogen
86
What defines a compound?
Two or more elements chemically combined in definite ratios
87
Can compounds be separated by physical means?
No
88
Give examples of compounds.
* Salt
* Water
* Carbon dioxide
89
What are physical properties?
Can be observed and measured without changing the substance
## Footnote
Examples include color, melting point, states of matter, and density.
90
Give examples of physical properties.
* Color
* Melting point
* States of matter
* Density
## Footnote
These properties can be measured without altering the substance.
91
What are physical changes?
Identity of substance stays the same
## Footnote
Examples include changes of state like melting and freezing, and dissolving sugar in water.
92
What is an example of a physical change?
* Melting
* Freezing
* Dissolving sugar in water
## Footnote
These changes lead to a different form of the same substance.
93
What are chemical properties?
Determined by chemical changes that are observed
## Footnote
Examples include flammability, acidity, and corrosiveness.
94
Give examples of chemical properties.
* Flammability
* Acidity
* Corrosiveness
## Footnote
These properties can only be observed during a chemical reaction.
95
What are chemical changes?
After reaction, original substance no longer exists
## Footnote
Examples include combustion and digestion.
96
What are indicators of a chemical reaction?
* Color change
* Heat
* Cloudiness
* Bubbles
## Footnote
These indicators signify that a chemical change has occurred.
97
True or False: Chemical changes lead to a different substance.
True
## Footnote
Chemical changes result in substances that are different from the original.
98
What is a chemical property?
A characteristic of a substance that describes its ability to undergo chemical changes.
99
What reaction produces rust?
Iron reacts with oxygen.
100
What is a defining feature of noble gases?
They are highly unreactive.
101
What is an example of a chemical change?
Combustion of gas.
102
What is produced on a metal toy due to chemical changes?
Rust.
103
What does quantitative data express?
Using numbers.
104
What does qualitative data express?
Using properties.
105
What is an extensive property?
A property that depends on the amount of matter.
106
Provide examples of extensive properties.
* Mass
* Length
107
What is an intensive property?
A property that does not depend on the amount of matter.
108
Provide examples of intensive properties.
* Density
* Temperature
* Color
109
What is the law of conservation of energy?
Energy cannot be created nor destroyed; it can only be converted from one form to another.
## Footnote
This principle is fundamental in physics and implies that the total energy in a closed system remains constant.
110
What is typically favored in energy states?
Lower energy is typically favored over higher energy.
## Footnote
Lower energy states are associated with greater stability in physical and chemical systems.
111
What does lower energy indicate in terms of stability?
Lower energy = more stable.
## Footnote
This relationship is important in understanding chemical reactions and physical processes.
112
What is the law of conservation of mass?
Matter cannot be created nor destroyed.
## Footnote
This law states that the mass of a substance before a chemical change is always equal to the mass of the substance after the change.
113
In a chemical change, what happens to the mass of substances?
The mass of substance before a chemical change is always equal to the mass of substance after a change.
## Footnote
This principle is critical for balancing chemical equations and understanding stoichiometry.
114
What is the arrangement criterion for elements in the periodic table?
Elements are arranged according to increasing atomic number
## Footnote
The atomic number represents the number of protons in an atom's nucleus.
115
What are periods in the periodic table?
Periods are boxes (elements) in horizontal rows
## Footnote
Each period corresponds to the filling of a different electron shell.
116
How are periods numbered in the periodic table?
Periods are numbered from top to bottom, but numbers are not usually printed
## Footnote
The absence of printed numbers can lead to confusion regarding the sequence.
117
What are groups in the periodic table?
Groups are vertical columns called chemical families
## Footnote
Elements in the same group often exhibit similar chemical properties.
118
How are groups identified in the periodic table?
Groups are identified by 2 rows of numbers across the top of the table (European and US Notations)
## Footnote
These notations help distinguish between different numbering systems used internationally.
119
True or False: Elements with similar properties are located in horizontal rows.
False
## Footnote
Similar properties are found in vertical columns, not horizontal rows.
120
What fundamental property leads to the similar behaviors of some elements?
Some elements had similar behaviors which must be due to some fundamental property
## Footnote
This property is often related to their electron configurations.
121
What is a molecule?
Unit consisting of 2 or more atoms chemically bonded together
122
Can a molecule consist of the same element?
Yes, a molecule can consist of the same element or different elements
123
What are diatomic molecules?
Molecules that consist of 2 atoms chemically bonded together
124
How many elements form diatomic molecules?
7 elements form diatomic molecules
125
List the 7 diatomic molecules.
* H2
* N2
* O2
* F2
* Cl2
* Br2
* I2
126
True or False: Some elements behave as single atoms.
False
127
What are the characteristics of metals?
Shiny, flexible, most are solids, ductile, malleable, good conductors
## Footnote
Mercury (Hg) is a liquid metal.
128
What does ductile mean in the context of metals?
Able to be drawn into wires
129
What does malleable mean in the context of metals?
Able to be pounded into thin sheets
130
Where are metals found on the Periodic Table?
On the left side
131
What are the characteristics of nonmetals?
Brittle, hard, not ductile, not malleable, poor conductors
## Footnote
Hydrogen (H2) is a nonmetal and is an exception.
132
Where are nonmetals found on the Periodic Table?
On the right side
133
What are the characteristics of metalloids?
Have properties of metals and nonmetals, semi-conductors, good and poor conductors
## Footnote
Metalloids are found along the stair-step line on the Periodic Table.
134
List some examples of metalloids.
* B (boron)
* Si (silicon)
* Ge (germanium)
* As (arsenic)
* Sb (antimony)
* Te (tellurium)
* At (astatine)
