Approx.
1
10
⋅
m
o
l
×
24
⋅
atoms
⋅
m
o
l
−
1
×
N
A
,
where
N
A
=
6.022
×
10
23
⋅
m
o
l
−
1
.
Explanation:
We take the quotient.....
Number of moles
=
Mass of substance
⋅
g
Molar mass
⋅
g
⋅
m
o
l
−
1
=
Mass of substance
⋅
g
Molar mass
⋅
g
⋅
m
o
l
−
1
=
1
1
m
o
l
=
m
o
l
And thus we get an answer with dimensions of
m
o
l
as we require...
And so we retake the quotient.......
Number of moles of glucose
=
18
⋅
g
180.16
⋅
g
⋅
m
o
l
−
1
=
?
?
⋅
m
o
l
.
We know that glucose,
C
6
H
12
O
6
, has a formula of
180.16
⋅
g
⋅
m
o
l
−
1
, i.e.
(
6
×
12.011
+
12
×
1.00794
+
6
×
16.00
)
⋅
g
⋅
m
o
l
−
1
=
?
?
⋅
g
⋅
m
o
l
−
1
......
We are not finished there, because we were asked to find the number of atoms in such a molar quantity, and there are 24 atoms in one molecule of glucose.
And so we multiply the molar quantity by number of atoms per mole, and then by Avogadro's number to get the number of atoms,
18
⋅
g
180.16
⋅
g
⋅
m
o
l
−
1
×
24
⋅
atoms
⋅
m
o
l
−
1
×
N
A
18
⋅
g
180.16
⋅
g
⋅
m
o
l
−
1
×
24
⋅
atoms
⋅
m
o
l
−
1
×
6.022
×
10
23
⋅
m
o
l
−
1
=
?
?
