00:04
All right.
00:05
So with this question, we're asked to find the average velocity of a nitrogen molecule.
00:11
And the equation we're going to use is this one right here.
00:15
This is the simplified version of the kinetic energy equation that was shown on the previous page of the book.
00:23
And what we're going to do is we're going to fill in these numbers, where r, of course, is the gas constant 8 .314.
00:29
So we're going to have, for the first one, we have 37 degrees celsius, which again, we always have to convert this into kelvin.
00:41
So if we add our 273 there, we get 310 kelvin.
00:48
So for part a, we're going to say that u, which is our velocity that we're looking for, is equal to the square root of three times the gas constant 8 .314.
01:03
Times the temperature 310 kelvin.
01:09
And then we have to divide by the molar mass.
01:12
But you got to be really careful here because the molar mass, in order for the units to cancel out correctly, has to be in kilograms per mole, not grams per mole.
01:24
So normally we would think of nitrogen as 28 grams per mole for n2...