MathBench > Measurement

Calculating Molar Weight

con man\ Congratulations, you have won a 20 gram ruby...

How many mols would that be? The molecular formula for ruby is Al2O3, so its molar weight is:

* +
* =

 

So if your ruby is 20 grams, and 102 grams is a mol, you can estimate that your ruby is about a fifth of a mol. Or, to be exact,

20 grams * 1/102 mols/g = 0.18 mol

20 grams is the same as about 100 carats and would be a huge crystal. Sadly such large crystals rarely have much value as gems. Too bad...

 

1
H
1.01
                                2
He
4.00
3
Li
6.94
4
Be
9.01
                    5
B
10.81
6
C
12.01
7
N
14.01
8
O
16.00
9
F
19.00
10
Ne
20.18
11
Na
22.99
12
Mg
24.30
                    13
Al
26.98
14
Si
28.09
15
P
30.97
16
S
32.07
17
Cl
35.47
18
Ar
39.98
19
K
39.10
20
Ca
40.09
21
Sc
44.96
22
Ti
47.88
23
V
50.94
24
Cr
51.94
25
Mn
54.94
26
Fe
55.85
27
Co
58.93
28
Ni
58.69
29
Cu
63.55
30
Zn
65.39
31
Ga
69.72
32
Ge
72.61
33
As
74.92
34
Se
78.96
35
Br
79.90
36
Kr
83.80