Question

Cooks use baking soda to make cakes light and fluffy. You might have used baking soda yourself. Baking soda is NaHCO3. A 0.1 M solution of baking soda in water has a [H+] of about 4.0 × 10–9. (You may prefer to think of the hydronium ion concentration, [H3O+], as 4.0 × 10–9.)
Write the formula for the calculation of pH, and then show each step as you calculate the pH of a 0.1 M solution of baking soda.

I am totally confused on this one. Could you also explain what you're doing as well?

Thank you

Answer 1

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