Answer:
pH of the benzoic acid solution = 3.35
Explanation:
Benzoic acid is a weak monoprotic acid
pKa = 4.2
⇒ Ka = 6.3 x 10⁻⁵
C₆H₅COOH ⇄ C₆H₅COO⁻ + H⁺
Initial concentration C molar 0 0
At equilibrium (c - cα) cα cα
Acid dissociation constant Ka = 
⇒ 6.3 x 10⁻⁵ = α²c ................(1)
(for weak electrolyte 1 -α = 1)
Concentration of benzoic acid C = 25 x 0.126 x 10⁻³ = 0.00315 molar
From eqn (1)
α² = 
⇒ α = √( )
⇒ α = 0.14
So concentration of H⁺ ion = 0.14 x 0.00315 = 0.000441
pH = - log 0.000441 = 3.35
We not considered H⁺ concentration of water because pH < 7
The process that occurs at the anode in an
electrochemical cell is the loss of electrons. The answer is number 2. Oxidation occurs as electrons are lost at the
anode at one of the electrodes in both an electrolytic cell and a
voltaic cell.
Answer:
c
Explanation:
the oxygen in the air and water from the rain caused oxidation causing the copper wire to become tarnished.
Yes it is balanced, and yes it is obeying the law of conservation of matter.
Formula for pH is pH = -log [H+]
you use 4.0x10^-9 and substitute in for [H+]
Fromula looks like this:
pH = -log (4.0x10^-9) - from here different calculators will require different buttons to push to get the answer
Solved out:
pH = -log (4.0x10^-9)
pH = -(-8.398) = 8.398 is the pH
