the concentration of OH ions in a household ammonia cleaning solution is0.0035M. Calculate the concentration of H ions.
would it be pH=-log (.0035)???
or Kc=1/.0035???
No. p(OH)=-log (.0035)
pH= 14-pOH
Are you reading carefully your problem statements?
To calculate the concentration of H ions (H+), you can use the principle of the self-ionization of water. In pure water, the concentration of H+ ions is equal to the concentration of OH- ions, which is 1x10^-7 M at 25°C. However, in an ammonia cleaning solution, the OH- ions come from the dissociation of ammonia (NH3).
The balanced chemical equation for the dissociation of ammonia in water is:
NH3 + H2O ⇌ NH4+ + OH-
In this equation, one molecule of ammonia (NH3) reacts with a water molecule (H2O) to form an ammonium ion (NH4+) and a hydroxide ion (OH-).
Given that the concentration of OH- ions in the ammonia cleaning solution is 0.0035 M, it means that the concentration of NH4+ ions (NH4+) is also 0.0035 M, as they are in equal quantities based on the balanced equation.
Now, to find the concentration of H+ ions, you can use the fact that water autoionizes to produce equal concentrations of H+ and OH- ions. Therefore, the concentration of H+ ions would be equal to 1x10^-7 M – 0.0035 M.
pH = -log[H+]
pH = -log(1x10^-7 – 0.0035)
pH ≈ -log(0.0035)
So, to find the pH, you would calculate -log(0.0035) using a calculator or any software with a logarithm function. This will give you the pH value of the ammonia cleaning solution.