00:01
So for this question, we are given the substance calcium silicate, and we are asked to determine the percent composition of this substance.
00:16
So the percent composition just means we are trying to find the percentage of each element within the molecular compound.
00:27
So by doing that, we're going to take the atomic weight of each element divided by the mass of the entire compound or formula.
00:43
So first, let's find the molecular mass or the mass of the entire.
00:49
So we are going to find the atomic weight for each element from the periodic table.
00:58
I'll do calcium and blue.
01:00
So calcium is 40 .08 atomic mass units.
01:07
Then we're going to add the atomic weight of silicone, which is 28 .09 atomic mass units, plus the atomic weight.
01:20
So the atomic weight of one oxygen is 16, but we have three of them.
01:27
So we will say three times the atomic weight of one oxygen, which is 16 atomic mass units.
01:35
So if you add those all together, you type in your calculator, the total molecular mass should be 116 .2 atomic mass units.
01:47
So now to find the percentage of each element, we just have to divide its atomic weight by the weight or mass of the entire molecule.
02:00
So first we'll do calcium.
02:04
So we just have one calcium...