On dissout dans l'eau distillée une masse m=0,25 g de benzoate de sodium C6H5CO2Na et un volume V, = 17,4 mL d'une solution (S) d'acide méthanoïque HCO₂H de concentration molaire C=0,10 mol.L' pour obtenir un mélange de volume V = 100,0 mL.
Données: pK = pK (C6H5COOH(aq)/C6H5CO2-(aq))=4,2; pK 2 = pK (HCOOH | HC2O-))=3,7 (aq) M(C6H5CO₂Na)=144 g.mol-¹

1) qu'il est le ph du melange ?

Sodium benzoate (C6H5CO2Na) is used as a foodpreservative.

1.) Calculate the pH in 0.060M sodium benzoate. Ka for benzoic acid(C6H5CO2H) is 6.5 x 10 -5.

2.) Calculate the concentrations of all species present (Na+,C6H5CO2-, C6H5CO2H, H3O+, and OH-) in 0.060M sodiumbenzoate.

I have no idea where to even begin with this problem. Please showme step by step with correct answer so I can try andunderstand.

THANK YOU!!!

The acid C6H5COOH dissociates according to the equation: C6H5COOH (aq) ⇌ C6H5COO‐ (aq) + H+ (aq) K = 6.4 x 10‐5 If the initial [C6H5CO2H] is 4.59 x 10‐3M, what are the equilibrium concentrations of C6H5COO‐ and H+ for this dislocation reaction?