We assume that we have Ka= 4.2x10^-13 (missing in the question)
and when we have this equation:
H2PO4 (-) → H+ + HPO4-
and form the Ka equation we can get [H+]:
Ka= [H+] [HPO4-] / [H2PO4] and we have Ka= 4.2x10^-13 & [H2PO4-] = 0.55m
by substitution:
4.2x10^-13 = (z)(z)/ 0.55
z^2 = 2.31x 10^-13
z= 4.81x10^-7
∴[H+] = 4.81x10^-7
when PH equation is:
PH= -㏒[H+]
= -㏒(4.81x10^-7) = 6.32
Answer: The mass
Explanation: ability to rust, flammability, and ability to combust are chemical properties.
The expression that can be used to determine Cl2O(g) is ;

<h3>Determine an expression that can be used to determine Cl2O(g)</h3>
The general expression for ΔS°rxn of a chemical reaction
ΔS°rxn = ∑mS°products - ∑nS°reactants
where ; m and n = stoichiometry coefficients
Considering the given reaction : H₂O(g) + Cl₂O(g) → 2HCIO (g)
S°rxn =
------- ( 2 )
Rearranging the equation above
Hence we can conclude that The expression that can be used to determine Cl2O(g) is ;

Learn more about stoichiometry : brainly.com/question/16060223