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Pressure Conversion Chart for Inorganic Chemistry

April 14, 2020

This is an experiment for the conversion factors for the Chapter 12 of Inorganic Chemistry.


Below are the equations we are using for gas laws.

Boyle's Law  P1V1=P2V2
Charles's Law V1T2 = V2T1  Temperature in kelvin
Gay Lussac's Law P1T2=P2T1 Temperature in kelvin
Conversion  of Temperature x °C  + 273.15  =  y K
Combined Gas Law P1V1T2=P2V2T1 Temperature in kelvin
Dalton's Law of Partial Pressure Total Pressure = P1 + P2 + P3
Graham's Law of Diffusion v1/v2 = √(M2/M1) v is velocity and M is the Molar Mass of a gas
Molar volume of a gas at STP 22.41 L at 273.15 K (0.0°C) and 101,325 pascals (1 atm)
Ideal Gas Law PV = nRT R=0.0821 atm L / mol K; 8.314 kPa L / mol K; 62,364 mmHg L/ mol K

So as you can guess, Chapter 12 is the next chapter and it is filled with math. And tomorrow is a math Wednesday.

Hopefully you have an empty water bottle handy for you to have a gas visual. With this chapter we are attempting to define the gas parameters of P for pressure, V for volume, n is the number of moles, T is temperature (in kelvin). 

Pressure is the first to be defined. It has been measured in many different units. Earlier in the semester I referred to 1 atmosphere of pressure in defining STP or with the standard conditions for ▲H. However we have the metric unit of a pascal or kilopascal (kPa) that converts 101.325 kPa = 1.000 atm. You fill your car tires and measure it in psi (pounds per square inch) or the barametric pressure on weather web sites is in mmHg (millimeters of mercury).

The pre-lab for the section is trying to blow up a balloon inside a water bottle or 2L empty pop bottle. What do you experience? Pressure!! (page 415) The template will have a different lab name.


Gases are fluid, have low density, can be compressed, and completely fill up a container. Great to know if you get the chance to travel into space. As long as you are not trying to fill the universe with oxygen, keep it local and you will be OK.

Try to figure out the simple barometer found on page 419. Notice that the air must reach the surface of the liquid mercury for it to measure. 

On page 421 1-4 you are asked to convert some pressures. I included the chart on the top of this page. Besides those 4 questions convert the odd numbers 1-9 on page 865 for homework this week April 14-17. I'll add on more for the next two weeks later.

Good luck.


Here is the additional work for Boyle's Law and Charles's Law 

Boyle's law is more of the gas filled syringe that is capped. Pushing down with more force will have a smaller volume of trapped gas.

Charles's law is the hot air balloon that is filled by heating the air not forcing more air into the balloon. Or the empty water bottle capped in the morning and left sitting in the hot car in the afternoon. Convert temps to Kelvin [°C + 273.15]  and to double the volume you must double the 273 to at least 546. Hot by any means.

Pages 423-428 in Chapter 12.
Boyle’s law. P1V1=P2V2.   P=pressure V=volume
Charles’s law. V1T2=V2T1 T=kelvin temp
Page 865-866 11-13, 19-21, 28-29, 32, 33

Continuing on pages 429-430 is Gay-Luccac's Law P1T2=P2T1  T=kelvin temp

431-432 Avogadro's Law n1V1=n2V2 where n is the number of moles

Page 867 40, 41, 46, page 432 5-9

Section 3 is the final section for the Gas Chapter. The ideal gas law combines the four previous gas laws into one law PV=nRT

P= Pressure usually atmospheres or kilopascals

V = Volume in liters

n = number of moles of the gas

R = Ideal gas law constant (8.314 L KPa/mol K  if using kPa for pressure or 0.0821 L atm/mol K if using atmospheres

T = temperature of gas in Kelvin units °C + 273.15

This runs from page 433-435. Remember to convert grams to moles by using the molar mass on the periodic table.

Diffusion is how you can smell Axe spray all the way down a hallway. We use Graham's law of diffusion to quantify the rate as a ration of the inverse of the molar mass of the gases.

With this you should suspect that a lighter gas will diffuse faster (easier) than a heavier gas slower (more massive/harder to move). With the mass to show a gas at a faster rate, the larger number is in the numerator so takin the square root will be a number greater than 1. (the ratio will be 1+/1 meaning it goes further in the same amount of time (covers more than a meter when the heavier gas covers a meter))

We all love stoichiometry. Gas stoichiometry is the bomb. With an equation like 3H2 + N2--> 2NH3 where all are gases at the same temperature and pressure, then the volumes contain the same number of moles of the gas. Equal ratios of the volumes react to completion. So in this examples, 6 gallons of hydrogen would react with 3 gallons of nitrogen to produce 4 gallons of ammonia. (Substitute liters, quarts, barrels for the volume.) This is very simplified stoichiometry. As with the others, there is always one that is in excess and one limiting. You run out of one and the other quits making the product.

Homework page 442 7-11

Vocabulary is on page 444

Review for the gas test online

page 446 33, 36, 37, 40, 41, 44, 45, 48, 49 

page 447 57, 60, 61, 64, 65

page 449 97

page 450 98-103

page 451 1-12


We will have Zoom discussions for classes at 2PM on Tuesday for 6th hour, 10AM on Wednesday for 2nd hour, and 2PM on Wednesday for 7th hour.

My ID is 998 720 8729

Password is 9jCxe6


Otherwise send me an e-mail to dladehoff@cusd4.org or dladehoff@gmail.com


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