00:01
Okay, so for this problem, we are starting with 25 grams of each substance, and we are converting it to moles.
00:10
So in order to do that, we have to use the molar mass.
00:15
For part a, we are starting with 25 grams of neon.
00:22
So whenever we start with grams, grams must go on the bottom, and we know that that grams equals one mole of that substance.
00:32
If we look on the periodic table, we find that the mass of neon is 20 .1.
00:38
So we're going to go 25 times 1 divided by 20 .18.
00:45
And when we do that, we get a mass, or moles, excuse me, of 1 .24 moles of n .e for part b.
00:57
Again, we're starting with 25 grams of o2.
01:03
If we're starting with grams, grams of o2, let's go on the bottom.
01:08
And that's always equal to one mole of that substance.
01:11
The grams of o2, if we look on the periodic table, is 16 plus 16, which gives us a mass of 32.
01:20
When we multiply this through, we're going to get rid of our grams.
01:24
We're left with moles.
01:26
And we're going to go 25 divided by 32.
01:29
And that gives us 0 .78 moles of o2.
01:35
For part c, we have 25 grams of aluminum hydroxide.
01:49
So if we start with grams of aluminum hydroxide, we have to have grams of aluminum hydroxide on the bottom.
01:56
And we're going to put one mole of that substance on the top...