# Calculating Pressures using different laws

Converting between Units of Pressure

Part A:

Convert 0.700atm of pressure to its equivalent in millimeters of mercury.

Express the pressure numerically in millimeters of mercury

Part B

The Pressure in car tires is often measured in pounds per square inch (lb/in2) with the recommended pressure being in the range of 25 to 45lb/in2. Suppose a tire has a pressure of 40.5lb/in2. Convert 40.5lb/in2. To its equivalent in atmospheres

Express the pressure numerically in atmospheres.

Part C

High pressure liquid chromatography (HPLC) is a method used in chemistry and biochemistry to purify chemical substances. The pressures used in this procedure range from around 500 kilopascals (500,000 Pa) to about 60,000,000Pa. It is often convenient to know the pressure in torr. If an HPLC procedure is running at a pressure of 1.61*10^8Pa what is it's funning pressure in torr?

Express the pressure numerically in torr

Introduction to the Ideal Gas Law

Part A

A balloon is floating around outside your window. The temperature outside is 31C , and the air pressure is 0.700atm . Your neighbor, who released the balloon, tells you that he filled it with 5.00moles of gas. What is the volume of gas inside this balloon?

Express your answer to three significant figures and include the appropriate units.

Part B

A 20.0mL gas cylinder is filled with 6.60moles of gas. The tank is stored at 49C . What is the pressure in the tank?

Express your answer to three significant figures and include the appropriate units.

Part C

A 160L. kiln is used for vitrifying ceramics. It is currently operating at 1115C, and the pressure is 0.9500atm . How many moles of air molecules are within the confines of the kiln?

Express your answer to three significant figures and include the appropriate units.

Part D

A 16.0L gas cylinder has been filled with 5.80moles of gas. You measure the pressure to be 3.10atm . What is the temperature inside the tank?

Express your answer to three significant figures and include the appropriate units.

Temperature and Pressure

Part A

A sample of ideal gas is in a sealed container. The pressure of the gas is 735torr, and the temperature is 7C. If the temperature changes to 58C with no change in volume or amount of gas, what is the new pressure P2 , of the gas inside the container?

Express your answer with the appropriate units.

Part B

Using the same sample of gas ( P1= 735torr , T1 = 7C ), we wish to change the pressure to 7350torr with no accompanying change in volume or amount of gas. What temperature T2, in Celsius, is needed to reach this pressure?

Express your answer with the appropriate units.

Interactive Simulation - Avogadro's Law

Part A

In the simulation, set the temperature of the sample gas to 304K. Click on the "Run" button, and observe how the number of moles of the gas varies with an increase in the volume of the gas. Then, click on the "Reset" button, set the temperature of the sample gas to 504K, and click on the "Run" button again.

Observe the graph produced in the simulation, and select the correct options listed below.

Check all that apply.

Volume is inversely proportional to the number of moles of the gas.

The volume of the sample gas increases linearly with the number of moles.

The pressure of the sample gas increases with an increase in volume.

The volume of the gas doubles when the number of moles of the gas is doubled at the same temperature.

Part B

Imagine that the gas shown in the simulation is an ideal gas such as helium. Notice that the final number of moles of gas is 1.00mol for each experimental run. You can find the final volume of the gas using the y axis of the graph shown.

Consider an experimental run at 273K where the initial number of moles (n1) is actually 1.00mol and the final number of moles (n2) is 2.00mol. Use the simulation to find the volume (V1) of 1.00mol of helium at 273K, and calculate the final volume (V2).

Express the volume to three significant figures, and include the appropriate units.

Part C

At 4.00L, an expandable vessel contains 0.864mol of oxygen gas. How many liters of oxygen gas must be added at constant temperature and pressure if you need a total of 1.84mol of oxygen gas in the vessel?

Express the volume to three significant figures, and include the appropriate units

Animation-P-V Relationships

Part C

A certain gas is present in a 15.0L cylinder at 4.0atm pressure. If the pressure is increased to 8.0atm , the volume of the gas decreases to 7.5L. Find the two constants Ki the initial value of K, and Kt, the final value of K, to verify whether the gas obeys Boyle's law.

Express your answers to two significant figures separated by a comma.

Part D

If a certain gas occupies a volume of 17L when the applied pressure is 8.5atm , find the pressure when the gas occupies a volume of 4.3L.

Express your answer to two significant figures, and include the appropriate units.

Octet Rule Exceptions for Electron Dot Structures

Part A

If the boron nitride molecule, BN, were to form, what would its structure look like?

Add bonds and lone pairs as necessary.

Covalent Lewis Dot Structures

Part B

A covalent compound is composed of a nitrogen atom, a hydrogen atom, and a carbon atom. How many electrons should the Lewis structure of the covalent compound contain?

Express your answer numerically as an integer.

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Converting between Units of Pressure

Part A:

Convert 0.700atm of pressure to its equivalent in millimeters of mercury.

Express the pressure numerically in millimeters of mercury

1atm=760 mm of mercury,

0.700 atm=532 mm of mercury (0.7*760=532)

Part B

The Pressure in car tires is often measured in pounds per square inch (lb/in2) with the recommended pressure being in the range of 25 to 45lb/in2. Suppose a tire has a pressure of 40.5lb/in2. Convert 40.5lb/in2. To its equivalent in atmospheres

Express the pressure numerically in atmospheres.

1 lb/in^2=6.805E-2 atm

40.5 lb/in^2=2.756 atm (40.5*6.805*10^(-2)=2.756)

Part C

High pressure liquid chromatography (HPLC) is a method used in chemistry and biochemistry to purify chemical substances. The pressures used in this procedure range from around 500 kilopascals (500,000 Pa) to about 60,000,000Pa. It is often convenient to know the pressure in torr. If an HPLC procedure is running at a pressure of 1.61*10^8Pa what is it's funning pressure in torr?

Express the pressure numerically in torr

101325 Pa=760 torr

Therefore, 1.61*10^8 Pa=(760/101325)*1.61*10^8 torr=1.21*10^6 torr

Introduction to the Ideal Gas Law

Part A

A balloon is floating around outside your window. The temperature outside is 31C , and the air pressure is 0.700atm . Your neighbor, who released the balloon, tells you that he filled it with 5.00moles of gas. What is the volume of gas inside this balloon?

Express your answer to three significant figures and include the appropriate units.

PV=nRT

0.7*V=5*0.0821*(31+273.15)

V=178.36 liter

Part B

A 20.0mL gas ...

#### Solution Summary

The following posting helps calculate pressures using different laws.

Calculate the activity coefficient for a liquid mixture that is in equilibrium with its vapors using both Raoult's law and Henry's law

Activity coefficients are used to calculate the actual concentration of non-ideal solutions. When two liquids are mixed together in different mole fractions, the mole fractions of their vapors will also be different. The partial pressures of each component is measured in both the liquid and vapor phase. With a knowledge of both mole fractions and partial pressures, we can determine the activity of each component from Raoult's law and Henry's law. The end goal of this problem is to derive and provide a relation between the activity coefficient, partial pressures and mole fraction from both Raoult's law and Henry's law individually.

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