The pH of 100 mL of a 0.10 M aqueous solution of Compound Z
is 11.30.
(a) Is Z an acid, a base, neither, or cannot be determined?
Justify your choice.
(b) Write the relevant Bronsted-Lowry equation showing how Z behaves in aqueous solution
Is 11.3 pH basic, neutral, or acid?
do you have to figure out what z is in order to show the bronsted-lowry equation?
No. http://en.wikipedia.org/wiki/Base_(chemistry)
acid
To determine whether Compound Z is an acid, a base, neither, or cannot be determined, we need to consider its pH value.
(a) To justify our choice, we need to understand the pH scale. The pH scale ranges from 0 to 14, with values below 7 indicating acidity (more hydrogen ions, H+) and values above 7 indicating alkalinity (more hydroxide ions, OH-). A neutral solution has a pH of 7.
In this case, the pH of Compound Z is 11.30, which is greater than 7. Therefore, Compound Z is alkaline or basic. Hence, we can conclude that Compound Z is a base.
(b) The Bronsted-Lowry theory defines an acid as a molecule that donates a proton (H+) and a base as a molecule that accepts a proton. In this case, Compound Z is behaving as a base.
The relevant Bronsted-Lowry equation showing how Compound Z behaves in aqueous solution would be:
Compound Z + H2O -> ZOH- + H+
In this equation, Compound Z accepts a proton (H+) from water (H2O) to form ZOH- (conjugate base) and a hydrogen ion (H+). This reaction shows the behavior of Compound Z as a base.
Overall: Compound Z is a base, and its behavior in aqueous solution is described by the equation: Compound Z + H2O -> ZOH- + H+