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 and water has a [H+] of about 4.0 X 10^-9. (You may prefer to think of the Hydronium ion concentration, [H3O+], as 4.0 X 10-9.) write the formula for the calculation of pH, and then show each job as you calculate the pH of 0.1 M solution of baking soda.,

Answer 1

Answer is: pH = 8,046.
c(H₃O⁺) = 4·10⁻⁹ M = 4·10⁻⁹ mol/L = 0,000000004 mol/L.
pH = -logc(H₃O⁺).
pH = -log(4·10⁻⁹ mol/L).
pH = -(-8,046) = 8,046.
When pH is less than seven (pH<7), solution is acidic.
When is equal seven (pH = 7), solution is neutral.
When pH is greater than seven (pH > 7), solution is basic (like this example).