<span>The answer is (1) chemically combined in a fixed proportion. Elements in a compound are bound by a chemical bond. So, oxygen and hydrogen are bound chemically. Further, their proportion never changes, it is always 1 oxygen atom and 2 hydrogen atoms in water. Thus, elements in a compound are chemically combined in a fixed proportion.Hope this helps. Let me know if you need additional help!</span>
You can see the periodic table one by one.
Pb(NO3)2 = PbN2O6
So there are
1Pb
2N
6O
and so you find the molecular mass from the periodic table and add all the numbers
Molacular mass of
Pb = 207
N = 14
O = 16
multiply it with the number of atoms
1Pb = 207 × 1 = 207
2N = 14 × 2 = 28
6O = 16 × 6 = 96
Molecular mass total = 207 + 28 + 96 = <u>3</u><u>3</u><u>1</u>
So the molecular mass is 331.
The answer is 0.25 M
Use the equation C1V1=C2V2
(.5)(100)=x(200)
x=0.25
