If you could explain what “merkels” are, the question would be more clear.
The number to the left of a chemical formula is called coefficients
Explanation
Coefficient is the number in front of a chemical formula.
It tell how many molecules of a given formula that are involved in a chemical reaction.
in 2H+O→ H2O the coefficient are 2,1,1
that is, 2 in front of H2
1 in front of O
1 in front of H2O
