Answer: 3.35x10²³atoms H2
Explanation: solution attached:
Convert mass of Al to moles
Do the mole to mole ratio between Al and H2
Convert moles of H2 to atoms using Avogadro's number.
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
The concentration of the Nitric acid solution : 0.114 M
<h3>Further explanation </h3>
Titration is a procedure for determining the concentration of a solution (analyte) by reacting with another solution whose known concentration (usually a standard solution) is called the titrant. Determination of the endpoint/equivalence point of the reaction can use indicators according to the appropriate pH range
Titrations can be acid-base titration, depositional titration, and redox titration. An acid-base titration is the principle of neutralization of acids and bases
Reaction
HNO₃ + NaOH → NaNO₃ + H₂O
Concentration a standard solution of sodium hydroxide : 0.0998 mol/dm³ , and the volume = 25 cm³
moles NaOH=

<em>From the equation, mol ratio HNO₃ : NaOH = 1 : 1, so mol HNO₃ = mol NaOH=</em><em>2.495 mlmoles</em>
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The volume of HNO₃ = 21.8 cm³, so the concentration :
