Ba2Cl
NaS2
The numbers are in subscript
8.98
×
N
A
cobalt atoms
Explanation:
N
A
,
Avogadro's number
specifies
6.0221
×
10
23
individual particles. It is simply another collective number like a dozen, or a score, or a gross.
N
A
has the property that
6.0221
×
10
23
individual cobalt atoms has a mass of
58.93
⋅
g
. How did I know that? Did I have it memorized?
So the quantity is
≈
54
×
10
23
cobalt atoms.
Balanced:
1. <span>Na2O + H2O ---> 2NaOH
2. </span><span>K2O + H2O ---> 2KOH
3. </span><span>MgO + H2O ---> Mg(OH)2
4. </span><span>CaO + H2O ---> Ca(OH)2
5. </span><span>SO2 + H2O ⇄ H2SO3
6. </span>SO3 + H2O ---> H2SO4
All except by 2 were balanced.