5. You have made the following two solutions: X) hydrogen ion concentration = 1 x 10-5M Y) pH = 4
State which statements below are true and which are false: a. Solution X contains 1 x 10-9M hydroxide ions.
b. Solution X contains more H+ ions than Solution Y. c. Solution Y contains 1 x 104M hydrogen ions.
d. Solution X is basic.
e. Solution Y is more acidic than solution X.
f. Solution X has ten times more OH- ions than solution Y.
a.
(H^+)(OH^-) = Kw -= 1E-14
b.
X = pH of 5; Y = pH of 4.
c.
pH = -log(H^+) Solve for (H^+)l.
d.
pH < 7 = acid
pH = 7 = neutral
pH > 7 = basic
e.
See b and d.
f.
pH + pOH = pKw = 14; then
pOH = -log(OH^-)
To determine which statements are true or false, let's break down each statement and compare the given information about the X and Y solutions.
a. Solution X contains 1 x 10-9M hydroxide ions.
To determine the hydroxide ion concentration, we can use the formula: [OH-] = Kw / [H+].
Given the hydrogen ion concentration of solution X as 1 x 10-5 M, we can substitute this value into the formula:
[OH-] = (1.0 x 10^-14) / (1.0 x 10^-5) = 1.0 x 10^-9 M.
So, statement a is true. Solution X contains 1 x 10^-9 M hydroxide ions.
b. Solution X contains more H+ ions than Solution Y.
Given the pH of solution Y as 4, we know that the hydrogen ion concentration in solution Y is 10^(-pH). Substituting the value of pH = 4 into the formula, we get [H+] = 10^(-4).
Since the hydrogen ion concentration in solution X is 1 x 10^-5 M, which is greater than 10^-4 M (the hydrogen ion concentration in solution Y), statement b is true. Solution X contains more H+ ions than Solution Y.
c. Solution Y contains 1 x 10^4M hydrogen ions.
This statement is false. The pH value of 4 corresponds to a hydrogen ion concentration of 10^(-4) M, not 10^4 M.
d. Solution X is basic.
To determine whether a solution is acidic or basic, we can look at the pH scale. A pH value below 7 indicates acidity, a pH of 7 is neutral, and a pH above 7 indicates basicity.
Given that the pH of solution X is not mentioned, we cannot determine its acidity or basicty solely based on the provided data. Therefore, statement d is indeterminable.
e. Solution Y is more acidic than solution X.
Since the pH of solution Y is 4 and the pH of solution X is unknown, we cannot compare their acidity directly. Therefore, statement e is indeterminable.
f. Solution X has ten times more OH- ions than solution Y.
From the calculation in statement a, we found that solution X has a hydroxide ion concentration of 1 x 10^-9 M, whereas there is no information provided about the hydroxide ions in solution Y. Thus, we cannot compare their concentration of hydroxide ions, making statement f indeterminable.
In summary, the true statements are:
a. Solution X contains 1 x 10^-9 M hydroxide ions.
b. Solution X contains more H+ ions than Solution Y.
The false statements are:
c. Solution Y contains 1 x 10^4 M hydrogen ions.