How many molecules of hydrogen peroxide are in 3 moles of hydrogen peroxide?
Answers
Answer:
So one molecule of hydrogen peroxide weighs in at 34.02 u.
The periodic table provides you with individual atomic masses. If you know the number and type of elements in a molecule you can add up the individual masses to find the molecular mass or molecular weight.
Find the molecular mass of calcium phosphate, Ca3(PO4)2
The molecule has 3 calcium atoms, 2 phosphate atoms and 8 O atoms in it. Stop and verify this for yourself. The Ca has a subscript 3 with it. The P has an assumed 1 and the O has a 4. However the PO4 group has a set of brackets around it with a subscript 2. The 2 means multiply everything inside the brackets by 2. So we end up with the 2 P and 8 O atoms.
Calculation: 3 X Ca = 3 X 40.08 u = 120.24 u
2 X P = 2 X 30.97 u = 61.94 u
8 X O = 8 X 16.00 u = 128.00 u
310.18 u
One molecule of calcium phosphate weighs 310.18 u