Question 1

What would the concentration of OH^- be if the concentration of H₃O⁺ was 1 × 10^-5M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-14

Accepted Answer

Using the equation provided, we can rearrange and solve for [OHS1U1P1-S1S1P0]:

[OHS1U1P1-S1S1P0] = KS1U1B1w / [HS1U1B13S1U1B0OS1U1P1+S1S1P0]

Plugging in the given values, we get:

[OHS1U1P1-S1S1P0] = (1 × 10S1U1P1-14S1S1P0) / (1 × 10S1U1P1-5S1S1P0)

Simplifying the exponents, we get:

[OHS1U1P1-S1S1P0] = 1 × 10S1U1P1-9S1S1P0

Therefore, the concentration of OHS1U1P1-S1S1P0 would be 1 × 10S1U1P1-9S1S1P0.

Question 2

Which is the stronger acid: H-F or H-I?

Accepted Answer

The strength of an acid is determined by its ability to release hydrogen ions. In this case, H-I is a stronger acid because the bond between H and I is weaker compared to the bond between H and F. Therefore, it is easier to break the H-I bond to form hydrogen ions, making H-I a stronger acid.

Question 3

In behaving as both an acid and a base, water reacts with itself to form ________.

Accepted Answer

Water can act as both an acid and a base in a process called self-ionization, forming hydronium ions (H3O+) and hydroxide ions (OH-).

Question 4

Which of the above illustrations shows a neutral aqueous solution?

Accepted Answer

The answer of Which of the above illustrations shows a...

Question 5

Qualitatively, what happens to the hydroxide ion concentration if you decrease the hydronium ion concentration?

Accepted Answer

Decreasing the hydronium ion concentration shifts the equilibrium of water dissociation to produce more hydroxide ions, thus increasing their concentration.

Question 6

Qualitatively, what happens to the hydronium ion concentration if you increase the hydroxide ion concentration?

Accepted Answer

Increasing the hydroxide ion concentration will decrease the hydronium ion concentration because they react to form water, maintaining the equilibrium constant for water (Kw).

Question 7

What is pH?

Accepted Answer

Both options A and B are correct. pH is a numerical scale used to represent acidity or basicity, and it is also the negative of the logarithm of the hydronium ion concentration. Option C is incorrect because it suggests that pH is the negative of the log of the acidity of a solution, when in fact pH is a measure of acidity. Option D is incorrect because it is not related to pH.

Question 8

What would the concentration of OH^- be if the concentration of H₃O⁺ was 1 × 10^-8M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-14

Accepted Answer

Given the ion product of water (Kw) is 1 × 10^-14 M^2, and the concentration of H3O+ is 1 × 10^-8 M, the concentration of OH- can be found by dividing Kw by the concentration of H3O+. Therefore, [OH-] = 1 × 10^-14 M^2 / 1 × 10^-8 M = 1 × 10^-6 M.

Question 9

Which of the following statements describes a neutral solution?

Accepted Answer

A neutral solution has an equal concentration of hydrogen ions (H+) and hydroxide ions (OH-), which means the pH is equal to 7. The formula for pH is -log[H+]. Therefore, a neutral solution would have a [H+] equal to [OH-], and when this is divided by itself, the resulting value is 1, as shown in choice E.

Question 10

Which of the following statements describes a basic solution?

Accepted Answer

A basic solution is characterized by a higher concentration of hydroxide ions ([OH-]) than hydrogen ions ([H+]), which means [OH-] > [H+].

Question 11

What would the concentration of H₃O⁺ be if the concentration of OH^- was 1 × 10^-11M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-14

Accepted Answer

Given the ion product of water (Kw) is 1 × 10^-14, and the concentration of OH^- is 1 × 10^-11 M, the concentration of H3O+ can be found using the relation Kw = [H3O+][OH^-]. Substituting the given values, 1 × 10^-14 = [H3O+](1 × 10^-11), solving for [H3O+] gives 1 × 10^-3 M.

Question 12

Which of the above illustrations shows an acidic aqueous solution?

Accepted Answer

The illustration shows the presence of more H+ ions than OH- ions in the solution, indicating an acidic solution. Option A and B show equal concentration of H+ and OH- ions, making them neutral solutions. Option D is not correct as all the options cannot be neutral solutions as option C is acidic.

Question 13

Which of the above illustrations shows a basic aqueous solution?

Accepted Answer

The illustration A shows a higher concentration of hydroxide ions (OH-) than hydrogen ions (H+) which indicates a basic aqueous solution. Illustrations B and C show a relatively equal concentration of H+ and OH- ions, suggesting a neutral solution. Therefore, only choice A is the best answer.

Question 14

Which of the following reactions illustrates an amphoteric compound?

Accepted Answer

The answer of Which of the following reactions illustrates an...

Question 15

Why is the H-F bond so much stronger than the H-I bond?

Accepted Answer

The H-F bond is stronger because of the small size of the fluorine atom, which is closer to the hydrogen atom and results in a stronger attraction between the two atoms. This attraction is known as the electronegativity difference, and it decreases as you move down the halogen group in the periodic table. Therefore, H-I has a weaker bond than H-F due to the larger size and lower electronegativity of the iodine atom. Choices A and B are incorrect because the physical state of the halogen at room temperature does not affect the bond strength. Choice D is also incorrect because the electronegativity of fluorine is higher than that of iodine and causes a stronger bond.

Question 16

What do the brackets in the following equation represent? [H₃O⁺] × [OH^-] = K_w

Accepted Answer

The answer of What do the brackets in the following...

Question 17

As the hydronium ion concentration increases, the pH ________.

Accepted Answer

pH is defined as the negative logarithm of the hydronium ion concentration ([H3O+]). As the [H3O+] increases, the logarithm term becomes more negative, and hence the pH decreases.

Question 18

How does a base like NH₃ raise the hydroxide ion concentration?

Accepted Answer

NH₃ acts as a base by accepting a proton from a water molecule, forming NH₄⁺ and OH^-, thus increasing the hydroxide ion concentration.

Question 19

What would the concentration of H₃O⁺ be if the concentration of OH^- was 1 × 10^-1M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-14

Accepted Answer

The answer of What would the concentration of H₃O⁺ be...

Question 20

Which of the following statements describes an acidic solution?

Accepted Answer

An acidic solution is characterized by having a higher concentration of hydrogen ions ([H+]) than hydroxide ions ([OH-]).

Quiz 10: Acids and Bases in Our Environment

What would the concentration of OH- be if the concentration of H3O+ was 1 × 10-5M? [H3O+] × [OH-] = Kw = 1 × 10-14