How many NH 3 molecules are there compared to NH 4 + ions in a typical ammonia solution?

In a typical ammonia solution, there are about 200 times as many NH 3 molecules as NH 4 + ions.

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Strong and Weak Acids and Bases

Q: What are the general steps for identifying a substance as an Arrhenius acid or base?

Step 1 : Identify the substance as an Arrhenius acid or base using the following criteria: The names of acids end in acid. Acid formulas have one of these forms: HX(aq) or H₂XyOₓ. Ionic compounds that contain hydroxide, carbonate, or hydrogen carbonate anions are basic. Ammonia, NH₃, is also a base. Step 2 : If the substance is an acid or base, determine whether it is strong or weak. We will consider all acids except HCl(aq), HNO₃, and H₂SO₄ to be weak. We will consider all bases except metal hydroxides to be weak.

Q: Why is ammonia classified as an Arrhenius base?

Ammonia is an Arrhenius base because it produces OH − ions when added to water.

39 important questions on Strong and Weak Acids and Bases

Identify each of the following as either an Arrhenius strong acid, an Arrhenius weak acid, an Arrhenius strong base, or an Arrhenius weak base: lithium hydroxide.

Lithium hydroxide is an Arrhenius strong base.

What happens to fish as the pH of water decreases according to the scale in the image?

As the pH of water decreases, fish reproduction is affected, and adult fish die.

How does a change of one pH unit affect the concentration of OH⁻ ions?

A change of one pH unit reflects a ten-fold change in OH⁻ ion concentration.

What is the pH range that indicates normal precipitation according to the image?

The pH range that indicates normal precipitation is 5.6.

What are the only weak Arrhenius bases you are expected to recognize?

The only weak Arrhenius bases you are expected to recognize are ionic compounds containing carbonate (CO₃²⁻) and hydrogen carbonate (HCO₃⁻) ions.

What is the pH of pure water?

Pure water is neutral and has a pH of 7.

What are the general steps for identifying a substance as an Arrhenius acid or base?

Step 1: Identify the substance as an Arrhenius acid or base using the following criteria:
- The names of acids end in acid. Acid formulas have one of these forms: HX(aq) or H₂XyOₓ.
- Ionic compounds that contain hydroxide, carbonate, or hydrogen carbonate anions are basic. Ammonia, NH₃, is also a base.
Step 2: If the substance is an acid or base, determine whether it is strong or weak.
- We will consider all acids except HCl(aq), HNO₃, and H₂SO₄ to be weak.
- We will consider all bases except metal hydroxides to be weak.

Identify each of the following as either an Arrhenius strong acid, an Arrhenius weak acid, an Arrhenius strong base, or an Arrhenius weak base: K₂CO₃.

K₂CO₃ is an Arrhenius weak base.

Why is ammonia classified as an Arrhenius base?

Ammonia is an Arrhenius base because it produces OH⁻ ions when added to water.

What is the example provided in Sample Study Sheet 8.1?

The example provided is Example 8.1.

What happens when sodium carbonate dissolves in water?

When sodium carbonate dissolves in water, the carbonate ions react with water in a reversible way to yield hydroxide ions.

Identify each of the following as either an Arrhenius strong acid, an Arrhenius weak acid, an Arrhenius strong base, or an Arrhenius weak base: hydrofluoric acid.

Hydrofluoric acid is an Arrhenius weak acid.

What is the reaction when Na₂CO₃ dissolves in water?

Na₂CO₃(s) → 2Na⁺(aq) + CO₃²⁻(aq)

What is the annual production of sodium hydroxide by the US chemical industry?

Each year, the US chemical industry produces over 10 billion kilograms of the base sodium hydroxide, NaOH.

What happens when ammonia is added to water at the molecular level?

When ammonia is added to water, NH₃ molecules are constantly gaining and losing H⁺ ions, but soon after the initial addition of ammonia to water, both changes proceed at an equal rate.

What is the main goal of Chapter 8.1?

One of the most important goals of this chapter is to broaden your understanding of chemical reactions by describing the chemical changes that take place when an acid is combined with a base.

What is the reaction of CO₃²⁻ with water?

CO₃²⁻(aq) + H₂O(l) ⇌ HCO₃⁻(aq) + OH⁻(aq)

What are some uses of sodium hydroxide mentioned in the text?

It is used for many purposes, including water treatment, vegetable oil refining, the peeling of fruits and vegetables in the food industry, and to make numerous other chemicals, including soaps and detergents.

How many NH₃ molecules are there compared to NH₄⁺ ions in a typical ammonia solution?

In a typical ammonia solution, there are about 200 times as many NH₃ molecules as NH₄⁺ ions.

How is oxalic acid identified in Example 8.1?

Oxalic acid is not on the list of strong acids—HCl(aq), HNO₃, and H₂SO₄—so it is a weak acid.

What does Fran drink to help neutralize some of her excess stomach acid?

Fran drinks some baking soda mixed with water. The baking soda contains a base that "neutralizes" some of her excess stomach acid.

What is the role of sodium hydrogen carbonate in the context provided?

Sodium hydrogen carbonate is found in fire extinguishers and mouthwashes.

What is an acid according to the modern form of the Arrhenius theory?

An acid is a substance that produces hydronium ions, H₃O⁺, when it is added to water, and an acidic solution is a solution with a significant concentration of H₃O⁺.

What is the reaction when NaHCO₃ dissolves in water?

NaHCO₃(s) → Na⁺(aq) + HCO₃⁻(aq)

What is the role of ammonia in the production of sodium hydroxide?

Over 15 billion kilograms of the base ammonia, NH₃, is produced each year. Although a water solution of ammonia is a common household cleaner, most of the NH₃ produced in the US is used to make fertilizers and explosives.

What is the identification of NaHCO₃ in Example 8.1?

NaHCO₃ is an ionic compound that contains hydrogen carbonate, so it is a base. Ionic compounds that contain hydroxide, such as potassium hydroxide, are strong bases.

What does Fran's salad dressing taste like, and why?

The vinegar in her salad dressing tastes sour, as do all acids.

What is a strong acid?

A strong acid, such as hydrochloric acid, HCl(aq), is a substance that undergoes a completion reaction with water such that each acid particle reacts to form a hydronium ion, H₃O⁺.

What is the reaction of HCO₃⁻ with water?

HCO₃⁻(aq) + H₂O(l) ⇌ H₂CO₃(aq) + OH⁻(aq)

According to the modern version of the Arrhenius theory, what happens when a base is added to water?

According to the modern version of the Arrhenius theory of acids and bases, a substance that contains hydroxide ions, OH⁻, when it is added to water. A solution that has a significant concentration of hydroxide ions is called a basic solution.

How is HCl(aq) identified in Example 8.1?

We know that hydrochloric acid, HCl(aq), is an acid because its name ends in "acid," and its formula has the form of a binary acid. It is found on the list of strong acids.

What does Fran use to wash her hands, and why does it feel slippery?

Fran washes her hands with soap made from the reaction of a strong base and animal fat. One of the reasons the soap is slippery is because all bases feel slippery on the skin.

What is a weak acid?

A weak acid is a substance that is incompletely ionized in water because of the reversibility of its reaction with water that forms hydronium ion, H₃O⁺.

Where is sodium hydrogen carbonate found?

Sodium hydrogen carbonate is found in fire extinguishers, baking powders, antacids, and mouthwashes.

What are examples of water-soluble hydroxides that are strong bases?

Examples include lithium hydroxide, LiOH, used in storage batteries and as a carbon dioxide absorbent in space vehicles, and potassium hydroxide, KOH, which is used to make some soaps, liquid fertilizers, and biodiesel.

What is the identification of ammonia, NH₃, in Example 8.1?

Ammonia, NH₃, is our example of an uncharged weak base.

What is the main topic of Chapter 8?

Chapter 8 is about Acids, Bases, and Acid-Base Reactions.

What happens when ammonia dissolves in water according to the text?

When ammonia, NH₃, dissolves in water, some hydrogen ions, H⁺, are transferred from water molecules to ammonia molecules, NH₃, producing ammonium ions, NH₄⁺, and hydroxide ions, OH⁻.

What does Table 8.1 summarize?

Table 8.1 summarizes how you can recognize substances as bases and how you can classify them as strong or weak bases.

The question on the page originate from the summary of the following study material:

An Introduction to Chemistry - Atoms First WebAssign Bundle | 9780984337903 | Chiral Publishing Company, et al

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