Answer:
B. , C. and D.
Step-by-step explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
pH scale generally runs from 1 to 14 where pH = 7 represents neutral medium, pH < 7 represents acidic medium and pH > 7 represents basic medium.
Also, pH + pOH = 14
(a) So, pOH = 11.21
pH = 14 - 11.21 = 2.79
The solution is acidic.
(b) pH = 9.42
The solution is basic.
c. [OH⁻] > [H⁺]
More concentration of hydroxide ions leads to basic solution.
d. [OH⁻]> 1.0 x 10⁻⁷ M
1.0 x 10⁻⁷ M leads to neutral solution and hydroxide ions concentration greater than this yields to basic solution.