00:01
The first statement is false.
00:07
Molecular formula can be a multiple of the empirical formula, meaning the empirical formula is a simplified ratio, but the molecular formula is the actual ratio of the atoms in the compound.
00:54
Statement 2, the 2 .02 gram sample of hydrogen contains the same number of molecules as 32 .0 grams of oxygen.
01:05
That's true because both of them represent one mole of the gas.
01:15
Number three, the average atomic mass of an element is equal to the mass of its most abundant isotope.
01:20
The false average atomic mass is a weighted average of all the isotopes.
01:58
When i say weighted average, i mean it takes into account the abundance of the isotopes.
02:09
So, for example, carbon -13 is approximately 1 % of all carbon.
02:17
So the 13 only carries 1 % of the weight or so in the average.
02:24
But it does make a difference because carbon's atomic mass is 12 .011, whereas the most abundant isotope is carbon -12.
02:42
Number four, the numerical value of the molar mass of a compound expressed in atomic mass units is the same as its molar mass expressed in grams.
02:52
It's false.
02:56
Molar mass is expressed compressed in grams per mole.
03:20
Number five, the fundamental unit for chemical quantity is the gram...