The subscripts tell you <em>how many atoms</em> of an element are in one formula unit of a compound.
If there is no subscript, there is only one atom of the element.
In one formula unit of Na₂PO₃F, there are
Two atoms of sodium (Na)
One atom of phosphorus (P)
Three atoms of oxygen (O)
One atom of fluorine (F)
Explanation:
The given data is as follows.
Flow of chlorine (Q) = 
Amount of liter present per day is as follows.

It is given that dosage of chlorine will be as follows.
10 mg/l =
kg/l
Therefore, total chlorine requirement is as follows.
Total chlorine requirement =
kg/day
= 100 kg/day
Thus, we can conclude that the kilograms of chlorine used daily at the given water treatment plant is 100 kg/day.
Answer:
Discharge of ions during electrolysis is affected by, current apllied, the time of electrolysis, electrode type, posiiton of metal in electrochemical.
Explanation:
2H2 + O2 → 2H2O
First, we will find the moles :
n H2 = m H2 / Mr H2
n H2 = 10 / 2
n H2 = 5 mole
n O2 = m O2 / Mr O2
n O2 = 5 / 16
n O2 = 0.3125 mole
n H2 / coef. H2 > n O2 / coef. O2
So, O2 is the limiting reactant
The mass of water produced :
n H2O = (coef. H2O / coef. O2) • n O2
n H2O = (2/1) • 0.3125
n H2O = 0.625 mole
m H2O = n H2O • Mr H2O
m H2O = 0.625 • 18
m H2O = 11.25 gr
Excesses reactant :
n H2 = 5 - 0.625 = 4.375 mole
m H2 = n H2 • Mr H2
m H2 = 4.375 • 2
m H2 = 8.75 gr