2A2 Relationships between Energy and Matter Flashcards
Explore how energy and matter shape the organization of matter, distinguish chemical and physical properties, and demonstrate conservation in processes, applying thermodynamic principles and models to explain these interactions. (117 cards)
1
Q
What is matter?
A
Anything that has mass and takes up space.
2
Q
What are the 4 states of matter?
A
- Solid
- Liquid
- Gas
- Plasma
3
Q
Define:
compound
A
Two or more elements chemically combined.
These compounds can have different properties compared to their constitutuent elements. Examples of compounds include water (H~2~O) or carbon dioxide CO~2~.
4
Q
True or False:
Matter can be classified by its physical and chemical properties.
A
True
Physical properties can be observed without changing the substance’s identity (e.g., density), while chemical properties describe how a substance reacts in chemical processes (e.g., reactivity with oxygen).
5
Q
Define:
Mixture
A
A combination of two or more substances that are not chemically bonded.
Mixtures can be either homogeneous (uniform composition) or heterogeneous (non-uniform composition).
6
Q
True or False:
A homogeneous mixture has a uniform composition throughout.
A
True
In homogeneous mixtures, the components are evenly distributed, like in air or saltwater.
7
Q
What is the main characteristic of a heterogeneous mixture?
A
The components are not evenly distributed.
Examples of heterogeneous mixtures include salad or granite, where you can distinguish the individual components.
8
Q
What is a solution?
A
A homogeneous mixture where one substance dissolves in another.
Solutions are typically liquid, but can also be gases or solids (e.g., alloys). The solute dissolves in the solvent.
9
Q
Fill in the blank:
A solution consists of a _______ dissolved in a _______.
A
solute; solvent
In a solution, the solute is the substance being dissolved, while the solvent is the substance doing the dissolving.
10
Q
True or False:
Colloids are mixtures where the particles are large enough to settle.
A
False
In these mixtures, the particles are small enough to remain suspended but too large to dissolve, like in milk or fog.
11
Q
Fill in the blank:
The particles in a _______ mixture can be easily seen and separated.
A
heterogeneous
Heterogeneous mixtures, like a salad or trail mix, allow the individual components to be visually distinguished and physically separated.
12
Q
What type of mixture is milk?
A
Colloid
Milk is a colloid because fat droplets are dispersed in water and remain suspended.
13
Q
True or False:
Chemical properties can be observed directly without a chemical reaction.
A
False
Chemical properties, such as reactivity or flammability, can only be observed when a substance undergoes a chemical change or reaction.
14
Q
What happens to matter during a physical change?
A
It changes form but not composition.
In physical changes, the substance’s identity remains the same; only the appearance or phase changes.
For example, ice melting into water still consists of H2O.
15
Q
What is corrosion?
A
A chemical reaction that breaks down metals.
A common example is the rusting of iron, where iron reacts with oxygen and water to form iron oxide, weakening the material.
16
Q
True or False:
Density is a chemical property.
A
False
Density is a physical property because it can be measured without changing the substance’s chemical identity.
For example, the density of water can be measured without changing its chemical identity.
17
Q
Fill in the blank:
The Triple Point refers to the condition where a substance exists in all three states of matter at once, under specific conditions of _______ and _______.
A
temperature, pressure
This refers to the unique set of conditions where solid, liquid, and gas phases coexist in equilibrium.
For water, this occurs at 0.01°C and a pressure of 611.2 pascals.
18
Q
What is a chemical change?
A
A reaction that forms new substances.
Chemical changes, like burning wood, produce new materials that have different properties from the original substance.
19
Q
What is a phase change?
A
The transformation of a substance from one state of matter to another.
Examples of phase changes include melting (solid to liquid), freezing (liquid to solid), and vaporization (liquid to gas).
20
Q
Fill in the blank:
When milk is left out at room temperature, it sours and becomes thicker due to the growth of bacteria, which produces lactic acid. The souring of milk is an example of a ______ change.
A
chemical
The souring of milk is a chemical change because bacteria ferment lactose into lactic acid, which alters the milk proteins, causing them to denature and coagulate. This thickens the milk and forms new substances.
21
Q
What is the opposite of melting?
A
Freezing
Freezing is the process where a liquid loses heat and turns into a solid. For example, water freezes into ice when the temperature drops below 0°C.
22
Q
Fill in the blank:
When dry ice (solid carbon dioxide) is left at room temperature, it changes directly from a solid to a gas without becoming a liquid. This process is called ______.
A
sublimation
Dry ice undergoes sublimation, where a solid changes directly into a gas without becoming a liquid.
23
Q
What is vaporization?
A
The process in which a liquid turns into a gas by gaining energy.
Vaporization can occur through boiling (when a liquid is heated to its boiling point) or evaporation (when molecules at the surface of a liquid gain enough energy to escape into the air).
24
Q
Define:
Condensation
A
The process where a gas turns into a liquid upon cooling.
For example, water vapor in the air condenses into liquid water on a cold surface, like a glass of ice-cold water.
25
What are the characteristics of a **solid**?
Has a **definite** shape and volume.
## Footnote
In solids, particles are *tightly packed* and vibrate in place, keeping the shape fixed.
26
What are the characteristics of a **liquid**?
Has a **definite volume** but no definite shape.
## Footnote
Liquids can flow and take the shape of their container, as the particles are not as tightly bound as in solids.
27
What **phase change** occurs when a gas turns directly into a solid without passing through the liquid phase?
Deposition
## Footnote
[Deposition](https://study.com/academy/lesson/phase-change-evaporation-condensation-freezing-melting.html#:~:text=Deposition%20is%20a%20phase%20change,turning%20straight%20into%20a%20gas.) is the phase transition where a gas turns directly into a solid, such as when water vapor forms frost on a cold surface.
28
What does the **Law of Conservation** state?
**Matter** cannot be created or destroyed, only transformed.
## Footnote
In both physical and chemical changes, the total mass remains constant, even if the form changes.
29
# Fill in the blank:
A common example of a \_\_\_\_\_\_ change is **rusting**.
chemical
## Footnote
Rusting is a chemical change where iron reacts with oxygen to form iron oxide, a new substance.
30
What is **energy** transformation?
**Changing** one form of energy to another.
## Footnote
For example, in a light bulb, electrical energy is transformed into light and thermal energy.
31
What are the most **common** types of energy?
* Chemical energy
* Mechanical energy
* Thermal energy
* Nuclear energy
* Electromagnetic energy
* Electrical energy
## Footnote
These energies can be either potential (stored) or kinetic (in motion).
32
What is **kinetic energy**?
Energy of motion
## Footnote
Kinetic energy depends on the mass and speed of an object, such as a moving car or a flying bird.
33
What is **potential energy**?
Stored energy
## Footnote
Potential energy can be gravitational (due to position) or chemical (due to bonds), like the energy stored in food or a raised object.
34
# True or False:
Kinetic energy **increases** with speed.
True
## Footnote
The faster an object moves, the more kinetic energy it has, as kinetic energy is proportional to the square of the speed.
35
What happens when chemical energy in food is **converted** to mechanical energy?
The body **uses** the energy to perform movement.
## Footnote
In biological systems, chemical energy from food is converted to mechanical energy to power muscles.
36
How can **electrical energy** be transformed in a circuit?
It can **transform** into light, heat, or mechanical energy.
## Footnote
For example, in a motor, electrical energy is converted to mechanical (kinetic) energy to move a fan or other device.
37
# True or False:
Kinetic energy **includes** chemical energy.
False
## Footnote
Chemical energy is a *form* of potential energy stored in chemical bonds, not kinetic energy.
38
# Fill in the blank:
A roller coaster at the **top** of a hill has energy due to its height. This is an example of \_\_\_\_\_\_\_\_ energy.
potential
## Footnote
The roller coaster has gravitational potential energy at the top of the hill, which is converted to kinetic energy as it descends.
39
# Fill in the blank:
A car **speeding** down a highway has energy due to its motion. This is an example of \_\_\_\_\_\_\_ energy.
kinetic
## Footnote
The car has kinetic energy because it is in motion, and its speed and mass determine the amount of energy it possesses.
40
# Define:
Heat
**Energy** from particle movement or vibrations.
## Footnote
Heat results from the kinetic energy of atoms or molecules moving or vibrating. It can be transferred through conduction, convection, or radiation.
41
# True or False:
Heat is **always** transferred from a cooler object to a warmer one.
False
## Footnote
Heat always transfers from *hot to cold* until equilibrium is reached (i.e., the temperatures balance).
42
# Define:
Temperature
A **measurement** of the average kinetic energy of particles.
## Footnote
Temperature quantifies the heat in a system, usually in Celsius, Kelvin, or Fahrenheit, and reflects how fast the particles move.
43
What is the **boiling point** of water in Celsius?
100°C
## Footnote
Water boils at 100°C at 1 atmosphere of pressure. Boiling points can change with altitude or pressure.
44
What is the **freezing point** of water in Kelvin?
273.15 degrees Kelvin
## Footnote
Freezing occurs at 0°C or 32°F, and this is equivalent to 273.15 K on the Kelvin scale.
45
# Define:
Absolute zero
The **point** where particle motion stops, at -273.15°C or 0K.
## Footnote
Absolute zero is theoretically the *lowest temperature* possible, where molecular motion ceases.
46
What are the **three modes** of heat transfer?
* Conduction
* Convection
* Radiation
## Footnote
**Heat moves** from hot to cold through direct contact (conduction), fluid movement (convection), or electromagnetic waves (radiation).
47
What is the **study** of energy transfer and its effects on matter called?
Thermodynamics
## Footnote
Thermodynamics deals with concepts like heat, work, and energy, such as the efficiency of engines or refrigerators.
48
What does the **first law** of thermodynamics state?
**Energy** cannot be created or destroyed, only transferred or transformed.
## Footnote
This law explains the conservation of energy in closed systems, such as in heat engines or chemical reactions.
49
# True or False:
Heat **flows** from hot to cold, and systems tend to increase in disorder (entropy), as stated in the **second law** of thermodynamics.
True
## Footnote
This law means that energy transformations are never fully efficient, and natural processes always lead to increased entropy.
50
# Fill in the blank:
The **third law** of thermodynamics states that as temperature approaches absolute zero, the \_\_\_\_\_\_\_\_ of a system approaches a constant value.
entropy
## Footnote
At absolute zero (0 K), a perfect crystal would have zero entropy, as the system reaches its lowest energy state.
51
# Define:
Specific heat
The amount of energy required to change a substance’s temperature by 1°C per unit mass.
## Footnote
Specific heat varies by material; for example, water has a high specific heat, meaning it resists temperature changes.
52
What is **convection**?
Heat transfer through the **movement** of fluids.
## Footnote
A pot of boiling water demonstrates convection as water molecules expand and circulate.
53
# Fill in the blank:
\_\_\_\_\_\_\_\_ is the transfer of heat through a **solid** without the movement of the substance itself.
Conduction
## Footnote
In [conduction](https://study.com/academy/lesson/mechanisms-of-heat-transfer-conduction-convection-radiation.html), heat is transferred through **direct contac**t, typically in solids, where particles vibrate and pass energy to neighboring particles.
54
# True or False:
Water has a **low** specific heat.
False
## Footnote
Water has a *high specific heat*, meaning it absorbs and retains heat well compared to other substances.
55
How is heat transferred through **radiation**?
Through **electromagnetic waves**.
## Footnote
[Radiation](https://study.com/academy/lesson/radiation-heat-transfer-the-stefan-boltzmann-law.html) transfers energy in the form of electromagnetic waves, such as the heat from the sun or a microwave.
56
What is a **heat engine**?
A **device** that converts thermal energy into mechanical energy.
## Footnote
Common examples are car engines and steam engines, where heat from fuel is converted into motion.
57
# True or False:
**Heat engines** can work by using only electrical energy.
False
## Footnote
Heat engines rely on thermal energy to perform mechanical work, not just electrical energy.
58
What is the conversion **equation** from Fahrenheit to Celsius?
C = (F - 32) * 5/9
## Footnote
This formula allows you to convert Fahrenheit temperature readings to Celsius. For example, 32°F equals 0°C.
59
How is **temperature** commonly measured?
Using a **thermometer**.
## Footnote
Thermometers can use different methods (e.g., liquid expansion, infrared, or digital sensors) to measure temperature.
60
# True or False:
The **boiling point** of water decreases as altitude increases.
True
## Footnote
At higher altitudes, atmospheric pressure is lower, so water boils at lower temperatures.
61
How do **impurities** affect the boiling point of water?
They **raise** the boiling point.
## Footnote
Adding salt to water increases the boiling point and decreases the freezing point, which is called *boiling point elevation*.
62
# True or False:
The **phases** of water are solid (ice), liquid (water), and gas (water vapor or steam), but not plasma.
False
## Footnote
In addition to solid, liquid, and gas, water can also exist as plasma under **extreme conditions**, such as *very high temperatures*.
63
What is an **endothermic** reaction?
A reaction that **absorbs** heat.
## Footnote
Endothermic reactions, such as photosynthesis, require energy input to proceed and lower the surrounding temperature.
64
What is an **exothermic** reaction?
A reaction that **releases** heat.
## Footnote
Exothermic reactions, such as combustion, release heat energy to the surroundings, increasing their temperature.
65
# Fill in the blank:
When a **cold pack** is activated, it absorbs heat from its surroundings. This is an example of a \_\_\_\_\_\_ reaction.
endothermic
## Footnote
Endothermic reactions, like the one in cold packs, absorb energy from the surroundings, causing a cooling effect.
66
# Fill in the blank:
When **wood** burns in a fireplace, it releases heat and light. This is an example of a \_\_\_\_\_\_ reaction.
exothermic
## Footnote
Exothermic reactions release energy, usually in the form of heat, light, or sound, warming their surroundings.
67
What does the prefix **endo-** mean in thermodynamics?
Inside
## Footnote
**Endo** comes from Greek, indicating that energy is absorbed into the system, as in endothermic reactions.
68
What does the prefix **exo-** mean in thermodynamics?
Outside
## Footnote
**Exo** comes from Greek, indicating that energy is released to the surroundings, as in exothermic reactions.
69
# True or False:
In an exothermic reaction, bond formation releases more energy than bond breaking.
True
## Footnote
In exothermic reactions, more energy is released when new bonds form than is required to break the original bonds.
70
# Define:
Enthalpy
A thermodynamic property that measures the **heat content** of a system.
## Footnote
[Enthalpy](https://study.com/learn/lesson/what-is-enthalpy-formula-heat-of-solution-formula.html) is critical in understanding energy changes during chemical and physical processes and is typically measured in joules (J) or kilo-joules (kJ).
71
# Define:
Entropy
The measure of **disorder** or **randomness** in a system.
## Footnote
Entropy reflects the tendency of systems to move towards greater disorder. As entropy increases, the system becomes less organized, and usable energy decreases.
72
Melting of ice is an example of which type of **reaction**?
Endothermic
## Footnote
The melting of ice **absorbs** heat, making it an endothermic reaction that requires energy to break the bonds between ice molecules.
73
What happens to energy during **freezing**?
Energy is **released** as heat.
## Footnote
Freezing occurs when a liquid loses energy and solidifies.
74
Photosynthesis is an example of which type of **reaction**?
Endothermic
## Footnote
In photosynthesis, plants **absorb** sunlight to convert carbon dioxide and water into glucose, which requires heat energy.
75
**Nuclear fission** is an example of which type of reaction?
Exothermic
## Footnote
Nuclear fission **releases** a large amount of energy when unstable atomic nuclei split, making it an exothermic reaction.
76
# Fill in the blank:
The **enthalpy** of reaction for endothermic reactions is \_\_\_\_\_\_\_.
ΔH > 0
| (positive change in enthalpy)
## Footnote
A positive enthalpy change (ΔH > 0) means the reaction absorbs heat from its surroundings.
77
# Fill in the blank:
The **enthalpy** of reaction for exothermic reactions is \_\_\_\_\_\_\_\_.
ΔH < 0
| (negative change in enthalpy)
## Footnote
A negative enthalpy change (ΔH < 0) indicates that energy is released during the reaction.
78
What defines a **closed system** in thermodynamics?
A system that allows **energy exchange** but no matter exchange with its surroundings.
## Footnote
In a closed system, energy can flow in and out, but mass remains constant within the system.
79
# Fill in the blank:
The **first law** of thermodynamics is also known as the \_\_\_\_\_\_\_\_\_.
Law of Conservation of Energy
## Footnote
This law states that energy cannot be created or destroyed; it can only change forms.
80
# True or False:
The total energy in the universe can **change** over time.
False
## Footnote
The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed. This means the total energy in an isolated system (like the universe) remains constant.
81
What are the most **common** units for measuring heat?
* Joules (J)
* Calories
* British Thermal Units (BTU).
## Footnote
Heat is the transfer of thermal energy, and these units quantify that energy. Temperature, however, is measured in Celsius, Kelvin, or Fahrenheit.
82
What is **calorimetry**?
The **process** of measuring heat transfer during physical or chemical changes.
## Footnote
Calorimeters are instruments used to measure heat changes in reactions. This helps determine properties such as specific heat capacity or enthalpy changes.
83
What does the unit **J/g°C** represent?
Joules per gram per degree Celsius.
## Footnote
This unit measures specific heat capacity, which tells you how much heat energy (in joules) is needed to raise the temperature of 1 gram of a substance by 1°C.
84
# Fill in the blank:
A **BTU** is the amount of energy required to raise the temperature of 1 pound of water by \_\_\_\_\_\_ degree Fahrenheit.
1
## Footnote
A BTU is used to measure energy in heating systems and is approximately equal to 1,055 joules.
85
What is the purpose of a **bomb calorimeter**?
To measure the heat released in combustion reactions.
## Footnote
Bomb calorimeters are used to determine the energy content of fuels and foods by measuring the heat produced when substances are burned under controlled conditions.
86
What does **Kinetic Molecular Theory** (KMT) describe?
The **behavior** of particles, especially in gases.
## Footnote
KMT helps explain properties like pressure, temperature, and volume by modeling the motion and collisions of molecules.
87
What are the **five** main assumptions of Kinetic Molecular Theory?
* Gases are composed of particles in random, constant motion.
* Gases move in a straight line until they collide.
* Gas molecules are not attracted to one another or the container.
* Collisions between gas molecules are perfectly elastic.
* Average kinetic energy depends only on the temperature of the gas.
## Footnote
Some sources may vary in the number of assumptions.
88
# True or False:
**Kinetic Molecular Theory** assumes that gas molecules are attracted to each other.
False
## Footnote
Kinetic Molecular Theory assumes that gas molecules have no intermolecular attractions and move independently.
89
# Fill in the blank:
**Boyle's Law** describes the \_\_\_\_\_\_\_ **relationship** between pressure and volume at constant temperature.
inverse
## Footnote
Boyle’s Law states that as the volume of a gas increases, its pressure decreases, and vice versa, provided the temperature is held constant. This is mathematically expressed as P1V1 = P2V2.
90
# Fill in the blank:
**Charles' Law** describes the \_\_\_\_\_\_\_ **relationship** between the temperature and volume of a gas when other factors are held constant.
direct
## Footnote
Charles' Law can be expressed as T1/V1 = T2/V2, showing how volume increases with temperature at constant pressure.
91
# Fill in the blank:
According to **Avogadro's Law**, if the number of moles of gas **increases**, the volume of the gas will \_\_\_\_\_\_\_\_, assuming temperature and pressure are constant.
increase
## Footnote
Avogadro’s Law shows that volume and moles are directly proportional, meaning if the number of moles increases, the volume increases in direct proportion, as long as temperature and pressure stay the same.
92
How is **kinetic energy** (KE) calculated for an ideal gas?
KE = (3/2) RT
## Footnote
where:
**R** is the gas constant
**T** is the temperature in Kelvin
Kinetic energy depends on temperature and the gas constant.
93
# True or False:
Tire pressure **increases** when the temperature decreases.
False
## Footnote
Cooler temperatures slow molecules, reducing tire pressure.
94
# Define:
Phase diagram
A graph showing the temperature and pressure conditions for solid, liquid, and gas phases.
## Footnote
Phase diagrams illustrate equilibrium and help predict phase behavior.
95
What are **supercritical fluids**?
Fluids **above** the critical point, exhibiting both liquid and gas properties.
## Footnote
Supercritical fluids can diffuse through solids like gases but dissolve substances like liquids.
96
# True or False:
The **critical point** is where liquid and gas phases merge, and phase transitions like condensation no longer occur.
True
## Footnote
Beyond the critical point, the distinction between liquid and gas disappears, and gases cannot be liquefied, regardless of pressure.
97
What is the **difference** between triple point and critical point?
**Triple point** is where all phases coexist; the **critical point** is where gas can't be turned into liquid.
## Footnote
The critical point marks the end of the liquid-gas boundary, while the triple point is where solid, liquid, and gas exist together.
98
What does a **heating curve** demonstrate?
Temperature vs. time
## Footnote
A heating curve shows how temperature changes with added heat, including phase transitions.
99
# Fill in the blank:
The average **kinetic energy** of gas molecules is directly proportional to the \_\_\_\_\_\_\_\_.
temperature (in Kelvin)
## Footnote
**Higher temperature** increases the kinetic energy of gas molecules, as the molecules move faster with increased heat.
100
# True or False:
**Gases** can be compressed because there is a significant amount of space between their molecules.
True
## Footnote
Gases have large spaces between molecules, allowing compression.
101
What is the ideal gas law **equation**?
PV = nRT
## Footnote
where:
P is pressure
V is volume
n is moles
R is the ideal gas constant
It describes the relationship between pressure, volume, temperature, and moles of gas.
102
What is the mathematical expression for **Avogadro’s Law**?
V₁/n₁ = V₂/n₂
## Footnote
This equation represents the relationship between the initial and final volumes (V₁, V₂) and the number of moles (n₁, n₂) of a gas, at constant temperature and pressure.
103
What is the **value** of the ideal gas constant **R** when using atmospheric pressure?
0.0821 L ⋅ atm / mol ⋅ K
## Footnote
R is constant in all gas law equations involving pressure, volume, and temperature.
104
What is the conversion **formula** from Celsius to Kelvin?
K = °C + 273.15
## Footnote
This conversion is crucial for gas law calculations, as temperature must be expressed in Kelvin, not Celsius, to ensure accurate results.
105
Calculate the **volume** of gas using the ideal gas law.
Given 0.988 mol, 1.47 atm, and 425 K.
V = 23.4 L
| R = 0.0821 L ⋅ atm / mol ⋅ K
## Footnote
Use the ideal gas law formula PV=nRT. Rearrange to solve for volume **V = nRT/P**. Substitute the given values to calculate volume.
106
Calculate the **number of moles** of gas using the ideal gas law.
Given 1.789 atm, 4.78 L, and 306.15 K.
n = 0.34 mol
| R = 0.0821 L ⋅ atm / mol ⋅ K
## Footnote
Use the ideal gas law formula PV=nRT. Rearrange to solve for moles **n = PV/RT**. Plug in the values for pressure, volume, temperature, and the ideal gas constant to find the number of moles.
107
# Fill in the blank:
The ideal gas constant is **expressed** as \_\_\_\_\_.
R
## Footnote
R is a key constant in the ideal gas law, ensuring consistent units across calculations.
108
What does the ideal gas law **combine**?
Boyle's, Charles's, and Avogadro's laws
## Footnote
These laws describe the relationship between **pressure**, **volume**, **temperature**, and **moles**.
109
What does **STP** stand for in gas law?
Standard Temperature and Pressure
## Footnote
STP refers to a **standard** set of conditions used in gas law calculations: a temperature of 0°C (273.15 K) and a pressure of 1 atm and provide a reference point for comparing the properties of gases and ensure *consistency* across different experiments and calculations.
110
# True or False:
An ideal gas is a gas that **follows** the ideal gas law.
True
## Footnote
Ideal gases follow the combined principles of Boyle’s, Charles’s, and Avogadro’s laws.
111
What **unit** is pressure measured in according to the ideal gas law?
Atmosphere (atm)
## Footnote
When using the gas constant R=0.0821L⋅atm/mol⋅K, pressure must be expressed in atm. Other units like pascals (Pa) or mmHg can be used with different values of R.
112
# True or False:
Water vapor in the air **behaves** exactly like an ideal gas.
False
## Footnote
Water vapor is a **real gas** and does not always follow the ideal gas law, especially at high pressures or low temperatures, where [intermolecular forces](https://study.com/academy/lesson/intermolecular-forces-in-chemistry-definition-types-examples.html) cause deviations from ideal behavior.
113
How is the **volume** of a gas measured?
in liters (L)
## Footnote
In gas law calculations, volume is typically measured in liters to maintain consistency with the ideal gas law equation (PV = nRT), ensuring that all units align properly.
114
# True or False:
In a **closed** container, if the temperature of the gas is doubled, its volume will also double.
False
## Footnote
According to the **Ideal Gas Law**, while temperature and volume are related (Charles' Law), the volume does not double if the temperature is doubled unless the pressure is held constant.
115
# Fill in the blank:
**Gay-Lussac's Law** states that the **pressure** of a gas is \_\_\_\_\_\_\_ proportional to its temperature when the volume is held constant.
directly
## Footnote
This means that if the temperature of a gas increases, its pressure will also increase, provided the volume doesn't change. The law can be mathematically represented as **P1/T1 = P2/T2**, where **P** is pressure and **T** is temperature in Kelvin.
116
What happens to the **pressure** inside a basketball when you dribble it on a hot day?
It increases.
## Footnote
As the temperature of the air inside the basketball rises (due to contact with the hot surface), the pressure increases according to **Gay-Lussac's Law**, which relates pressure and temperature at constant volume.
117
# True or False:
When you inflate a balloon, the gas inside does not **obey** the ideal gas law because it is not in a rigid container.
False
## Footnote
Even though a balloon is flexible, the gas inside still follows the ideal gas law, assuming conditions of temperature, pressure, and volume are controlled, and the gas behaves ideally within the balloon's limits.
