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Matter can exist in three different states: gas, liquid, and solid.
Matter can exist in three different states: gas, liquid, and solid.
True
Which of the following can be used to completely specify the condition of any state of matter?
Which of the following can be used to completely specify the condition of any state of matter?
What is the formula for calculating molar volume?
What is the formula for calculating molar volume?
Volume / number of moles
Gases are fluids.
Gases are fluids.
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Gases occupy a fixed volume.
Gases occupy a fixed volume.
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Molecules in a gas are in continuous random motion.
Molecules in a gas are in continuous random motion.
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Liquids are fluids that maintain a fixed volume.
Liquids are fluids that maintain a fixed volume.
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Liquid molecules are closer together than gas molecules.
Liquid molecules are closer together than gas molecules.
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Liquid molecules are in a state of continuous random motion just like gas molecules.
Liquid molecules are in a state of continuous random motion just like gas molecules.
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Solid molecules are tightly packed together.
Solid molecules are tightly packed together.
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Solids can take the shape of their container.
Solids can take the shape of their container.
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The density and molar volume of gases do not change significantly with temperature and pressure.
The density and molar volume of gases do not change significantly with temperature and pressure.
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The ideal gas law states that PV = nRT.
The ideal gas law states that PV = nRT.
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R, the universal gas constant, is equal to 8314 J K-1 mol-1.
R, the universal gas constant, is equal to 8314 J K-1 mol-1.
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A perfect gas obeys the ideal gas law exactly at all temperatures and pressures.
A perfect gas obeys the ideal gas law exactly at all temperatures and pressures.
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Real gases do not obey the ideal gas law at any temperature or pressure.
Real gases do not obey the ideal gas law at any temperature or pressure.
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As pressure decreases, real gases deviate more from the ideal gas law.
As pressure decreases, real gases deviate more from the ideal gas law.
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How many moles of ammonia are present in 0.95 g of ammonia gas?
How many moles of ammonia are present in 0.95 g of ammonia gas?
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What is the pressure exerted by a sample of Nitrogen at 1500 kPa and 100 mL that is allowed to expand to 10^4 cm³ at constant temperature?
What is the pressure exerted by a sample of Nitrogen at 1500 kPa and 100 mL that is allowed to expand to 10^4 cm³ at constant temperature?
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Boyle's Law states that the pressure of a gas is inversely proportional to its volume at constant temperature.
Boyle's Law states that the pressure of a gas is inversely proportional to its volume at constant temperature.
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Gay-Lussac's Law states that at constant temperature, the volume of a gas is directly proportional to its pressure.
Gay-Lussac's Law states that at constant temperature, the volume of a gas is directly proportional to its pressure.
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To what temperature must a 10^-3 m³ sample of an ideal gas be cooled from 25°C in order to reduce its volume to 10^-4 m³?
To what temperature must a 10^-3 m³ sample of an ideal gas be cooled from 25°C in order to reduce its volume to 10^-4 m³?
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Avogadro's Law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
Avogadro's Law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
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The molar volume of an ideal gas is constant for all gases at the same temperature and pressure.
The molar volume of an ideal gas is constant for all gases at the same temperature and pressure.
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Dalton's Law states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases.
Dalton's Law states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases.
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The mole fraction of a gas in a mixture is the proportion of that gas's molecules relative to the total number of gas molecules in the mixture.
The mole fraction of a gas in a mixture is the proportion of that gas's molecules relative to the total number of gas molecules in the mixture.
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Study Notes
States of Matter
- Matter exists in three states: gas, liquid, and solid.
- The state of matter can be defined by pressure (P), temperature (T), and molar volume (Vm).
- Molar volume (Vm) is calculated by dividing the volume (V) by the number of moles (n) of the substance (Vm = V/n).
Gases
- Gases are fluids that occupy the entire volume of their container.
- Gas molecules are widely separated and move randomly.
Liquids
- Liquids are fluids, but they take the shape of their container.
- Molecules in a liquid are closer together than in a gas but are still in motion, albeit in a restricted manner.
- Liquids do not necessarily fill their container entirely.
Solids
- Solid molecules are tightly packed.
- Solids have a defined and rigid shape, regardless of the container.
Equation of State
- The condition of any state of matter can be fully described by pressure (P), temperature (T), and molar volume (Vm).
- For liquids and solids, a single density or molar volume value can represent their behavior over a wide range of temperatures and pressures, without significant loss of accuracy.
- For gases, density and molar volume change considerably with temperature and pressure. An equation of state (EOS) is necessary to relate these properties.
Ideal Gas Laws
- The pressure (P), volume (V), temperature (T) and number of moles (n) of an ideal gas are related by the equation PV = nRT.
- R is the universal gas constant, typically 8.314 J K⁻¹ mol⁻¹ or 8.314 kJ K⁻¹ kmol⁻¹.
- A gas that perfectly obeys this equation at all pressures and temperatures is called an ideal gas or perfect gas.
- Real gases approximate ideal gas behavior at very low pressures.
Worked Example 1
- Calculate the pressure exerted by 0.95 g of ammonia gas in a 300 mL container at 30°C.
- The molar mass of ammonia (NH₃) is 17.03 g/mol
- The value of the universal gas constant (R) is 8.314 J mol⁻¹ K⁻¹.
- Provide the answer in SI units (Pascals).
- Steps shown to calculate the pressure including steps for conversion to SI units.
Boyle's Law
- At constant temperature and amount (number of moles), the pressure of a given amount of gas is inversely proportional to the volume of the gas.
- PV = constant (at constant temperature and number of moles)
Worked Example 2
- Calculate the final pressure of a nitrogen sample, which initially has a pressure of 1500 kPa and 100 mL and is allowed to expand to 10^4 cm³ (or mL) at a constant temperature of 25°C.
Explanation of Boyle's Law
- If you halve the volume of a gas, the pressure will double (at constant temperature and amount of gas).
- More gas molecules collide with the container walls in a given time.
- The average force exerted by these collisions increases which means the pressure increases.
Isotherms of an Ideal Gas
- A graph of pressure (P) vs volume (V) at constant temperature (T) is called an isotherm.
- On the isotherm, pressure and volume are inversely proportional to each other.
- Isotherms are curves, with decreasing pressure as volume increases.
- Higher temperatures result in higher isotherms.
Gay-Lussac's Law
- At constant pressure and amount (number of moles), the volume of a gas is directly proportional to its absolute temperature.
- A specific gas sample will have a greater volume at a higher temperature
Worked Example 3
- A 10⁻³ m³ sample of an ideal gas is cooled from 25°C in order to lower its volume to 10⁻⁴ m³ at what temperature? Assume the pressure remains constant.
Avogadro's Law
- At constant temperature and pressure, the volume of an ideal gas is directly proportional to the number of moles of gas present (V α n).
- Equal volumes of different ideal gases at the same temperature and pressure contain the same number of molecules.
- Molar volume (Vm) of a gas is the volume occupied by one mole of the gas. Vm is constant for all gases under the same conditions of temperature and pressure.
Mixture of Ideal Gases
- The total pressure exerted by a mixture of ideal gases is the sum of the partial pressures exerted by each individual gas if it occupied the same volume alone.
- The partial pressure of each gas depends on its mole fraction and the total pressure.
Mole Fraction
- Mole fraction (xᵢ) of a gas "i" in a mixture is the ratio of the number of moles of that gas to the total number of moles in the mixture.
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Description
Explore the fundamental concepts of matter and its three states: gas, liquid, and solid. This quiz covers the defining properties such as pressure, temperature, and molar volume, and how these characteristics vary among different states. Test your knowledge on the behavior of gases, liquids, and solids.
