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### Units

Posted: Sun Jan 13, 2019 6:19 pm
There have been several different units that have been floating throughout my discussion and lectures so far. What is torr? What is bar? How do we find these and are these related in anyway?

### Re: Units

Posted: Sun Jan 13, 2019 6:21 pm
The torr is a unit of pressure and is defined as exactly of a standard atmosphere. A bar is a pressure unit defined as 100 kilopascals. This makes one atmosphere nearly equal to one bar. 1 bar = 750.06375541921 Torr

### Re: Units

Posted: Sun Jan 13, 2019 6:34 pm
There are several difference units that can be used to describe the pressure of a gas (bar, atm, mmHg, torr etc...). While any of them can be used to describe the pressure of a gas, when doing calculations using the ideal gas law (PV=nRT), you need to make sure to use the correct gas constant (R) which is determined by what unit of pressure you want or by what unit of pressure you are given. In general, the books usually uses atm (which has a R value of ~0.082).

### Re: Units

Posted: Sun Jan 13, 2019 6:38 pm