Unit 9 - Strength Of Acids And Bases

1. The ______ of solution is a measure of the concentration of hydronium ions in it.

Concentration

Indicator

PH

Strength

pH is a measure of the concentration of hydronium ions in a solution. It indicates the acidity or alkalinity of a solution on a scale from 0 to 14, with lower values indicating higher acidity and higher values indicating higher alkalinity. pH is determined by the concentration of hydronium ions, which are formed when water molecules react with hydrogen ions. Therefore, the correct answer is pH.

Explanation

pH is a measure of the concentration of hydronium ions in a solution. It indicates the acidity or alkalinity of a solution on a scale from 0 to 14, with lower values indicating higher acidity and higher values indicating higher alkalinity. pH is determined by the concentration of hydronium ions, which are formed when water molecules react with hydrogen ions. Therefore, the correct answer is pH.

2. ______ are solution containing ions that react with acids or bases to minimize their effects.

Buffers

Enzymes

Indicators

Hydroxides

Buffers are solutions that contain ions that react with acids or bases to minimize their effects. They work by maintaining a relatively constant pH level in a solution, even when small amounts of acid or base are added. This is achieved through a combination of weak acids and their conjugate bases, or weak bases and their conjugate acids, which can accept or donate protons to maintain the pH. Buffers are commonly used in biological and chemical laboratories to maintain the stability and control the pH of solutions during experiments.

Explanation

Buffers are solutions that contain ions that react with acids or bases to minimize their effects. They work by maintaining a relatively constant pH level in a solution, even when small amounts of acid or base are added. This is achieved through a combination of weak acids and their conjugate bases, or weak bases and their conjugate acids, which can accept or donate protons to maintain the pH. Buffers are commonly used in biological and chemical laboratories to maintain the stability and control the pH of solutions during experiments.

3. In chemical equations describing ionization, what do double arrows pointing in opposite directions indicate?

The reaction rate is doubled.

There is twice as much product as reactant.

The reactant is a strong acid.

The ionization reaction is incomplete.

The double arrows pointing in opposite directions in a chemical equation indicate that the ionization reaction is incomplete. This means that only a fraction of the reactants have been converted into products, and the reaction has not reached equilibrium.

Explanation

The double arrows pointing in opposite directions in a chemical equation indicate that the ionization reaction is incomplete. This means that only a fraction of the reactants have been converted into products, and the reaction has not reached equilibrium.

4. The strength of an acid or base depends on ______.

How many hydrogen atoms are contained in each molecule of the acid or base.

How quickly they form salts when they react with metals

How completely it ionizes in water

How many hydroxide groups are on each molecule of the acid or base

The strength of an acid or base depends on how completely it ionizes in water. When an acid or base ionizes in water, it breaks apart into ions. The more ions that are formed, the stronger the acid or base is considered to be. This is because a higher concentration of ions leads to a higher conductivity of the solution and a stronger acidic or basic behavior. Therefore, the degree of ionization in water is a key factor in determining the strength of an acid or base.

Explanation

The strength of an acid or base depends on how completely it ionizes in water. When an acid or base ionizes in water, it breaks apart into ions. The more ions that are formed, the stronger the acid or base is considered to be. This is because a higher concentration of ions leads to a higher conductivity of the solution and a stronger acidic or basic behavior. Therefore, the degree of ionization in water is a key factor in determining the strength of an acid or base.

5. Which of the following has the highest pH?

Pure water

Vinegar

Ammonia

Vitamin C

Ammonia has the highest pH among the given options. pH is a measure of the acidity or alkalinity of a solution, with values ranging from 0 to 14. A pH above 7 is considered alkaline or basic. Ammonia is a basic compound and has a pH of around 11-12 when dissolved in water. Pure water has a pH of 7, which is neutral. Vinegar and vitamin C are acidic substances, with vinegar having a pH of around 2.4-3.4 and vitamin C having a pH of around 2.2-2.8. Therefore, ammonia has the highest pH.

Explanation

Ammonia has the highest pH among the given options. pH is a measure of the acidity or alkalinity of a solution, with values ranging from 0 to 14. A pH above 7 is considered alkaline or basic. Ammonia is a basic compound and has a pH of around 11-12 when dissolved in water. Pure water has a pH of 7, which is neutral. Vinegar and vitamin C are acidic substances, with vinegar having a pH of around 2.4-3.4 and vitamin C having a pH of around 2.2-2.8. Therefore, ammonia has the highest pH.

6. Which two terms refer to the amount of acid or base dissolved in solution?

Dilute and concentrated

Strong and dilute

Weak and concentrated

Strong and weak

The terms "dilute" and "concentrated" refer to the amount of acid or base dissolved in a solution. A dilute solution has a low concentration of acid or base, meaning there is a small amount of it dissolved in the solution. On the other hand, a concentrated solution has a high concentration of acid or base, indicating that there is a large amount of it dissolved in the solution. Therefore, the correct answer is dilute and concentrated.

Explanation

The terms "dilute" and "concentrated" refer to the amount of acid or base dissolved in a solution. A dilute solution has a low concentration of acid or base, meaning there is a small amount of it dissolved in the solution. On the other hand, a concentrated solution has a high concentration of acid or base, indicating that there is a large amount of it dissolved in the solution. Therefore, the correct answer is dilute and concentrated.