Free Printable Acids and Bases Worksheets - Free Printable

Problem Analysis:

The task involves understanding and applying the Brønsted-Lowry theory of acids and bases, which defines:
- Acids as hydrogen ion donors (H⁺ donors).
- Bases as hydrogen ion acceptors (H⁺ acceptors).

We will solve each part step by step.

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Part 1: Identify H⁺ Donors and Acceptors

#### a) HNO₃(aq) + H₂O(l) → H₃O⁺(aq) + NO₃⁻(aq)

- HNO₃ donates a proton (H⁺) to H₂O.
- H⁺ donor (acid): HNO₃
- H⁺ acceptor (base): H₂O

#### b) C₂H₅NH₂(aq) + H₂O(l) → C₂H₅NH₃⁺(aq) + OH⁻(aq)

- H₂O donates a proton (H⁺) to C₂H₅NH₂.
- H⁺ donor (acid): H₂O
- H⁺ acceptor (base): C₂H₅NH₂

#### c) CH₃COOH(aq) + H₂O(l) → CH₃COO⁻(aq) + H₃O⁺(aq)

- CH₃COOH donates a proton (H⁺) to H₂O.
- H⁺ donor (acid): CH₃COOH
- H⁺ acceptor (base): H₂O

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Part 2: Write the Formulas for the Conjugate Base of Each Acid

#### a) H₂SO₃
- H₂SO₃ donates one H⁺ to form HSO₃⁻.
- Conjugate base: HSO₃⁻

#### b) HCO₃⁻
- HCO₃⁻ donates one H⁺ to form CO₃²⁻.
- Conjugate base: CO₃²⁻

#### c) NH₄⁺
- NH₄⁺ donates one H⁺ to form NH₃.
- Conjugate base: NH₃

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Part 3: Write the Formulas for the Conjugate Acid of Each Base

#### a) H₂O
- H₂O accepts one H⁺ to form H₃O⁺.
- Conjugate acid: H₃O⁺

#### b) CO₃²⁻
- CO₃²⁻ accepts one H⁺ to form HCO₃⁻.
- Conjugate acid: HCO₃⁻

#### c) PH₃
- PH₃ accepts one H⁺ to form PH₄⁺.
- Conjugate acid: PH₄⁺

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Part 4: Identify Whether Each Molecule or Ion Can Act as an Acid or Base According to Different Theories

We will analyze each molecule/ion under the Arrhenius, Brønsted-Lowry, and Lewis theories.

#### Definitions Recap:
1. Arrhenius Theory:
- Acid: Produces H⁺ in water.
- Base: Produces OH⁻ in water.

2. Brønsted-Lowry Theory:
- Acid: Proton (H⁺) donor.
- Base: Proton (H⁺) acceptor.

3. Lewis Theory:
- Acid: Electron pair acceptor.
- Base: Electron pair donor.

#### Analysis of Each Compound:

| Molecule/Ion | Acid or Base | Arrhenius | Brønsted-Lowry | Lewis |
|------------------|------------------|---------------|--------------------|-----------|
| Br⁻ | Base | – | ✓ (accepts H⁺) | ✓ (donates e⁻ pair) |
| CN⁻ | Base | – | ✓ (accepts H⁺) | ✓ (donates e⁻ pair) |
| H₂CO₃ | Acid | ✓ (produces H⁺) | ✓ (donates H⁺) | ✓ (accepts e⁻ pair) |
| NH₃ | Base | – | ✓ (accepts H⁺) | ✓ (donates e⁻ pair) |
| HNO₂ | Acid | ✓ (produces H⁺) | ✓ (donates H⁺) | ✓ (accepts e⁻ pair) |
| Ba(OH)₂ | Base | ✓ (produces OH⁻) | ✓ (accepts H⁺) | ✓ (accepts e⁻ pair) |
| HCl | Acid | ✓ (produces H⁺) | ✓ (donates H⁺) | ✓ (accepts e⁻ pair) |
| AlCl₃ | Acid | – | ✓ (accepts OH⁻, acts as Lewis acid) | ✓ (accepts e⁻ pair) |
| Cl⁻ | Base | – | ✓ (accepts H⁺) | ✓ (donates e⁻ pair) |
| KOH | Base | ✓ (produces OH⁻) | ✓ (accepts H⁺) | ✓ (accepts e⁻ pair) |
| IO₃⁻ | Base | – | ✓ (accepts H⁺) | ✓ (donates e⁻ pair) |
| CH₃COOH | Acid | ✓ (produces H⁺) | ✓ (donates H⁺) | ✓ (accepts e⁻ pair) |

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Final Answer:

#### Part 1:
a) H⁺ donor: HNO₃, H⁺ acceptor: H₂O
b) H⁺ donor: H₂O, H⁺ acceptor: C₂H₅NH₂
c) H⁺ donor: CH₃COOH, H⁺ acceptor: H₂O

#### Part 2:
a) HSO₃⁻
b) CO₃²⁻
c) NH₃

#### Part 3:
a) H₃O⁺
b) HCO₃⁻
c) PH₄⁺

#### Part 4:
| Molecule/Ion | Acid or Base | Arrhenius | Brønsted-Lowry | Lewis |
|------------------|------------------|---------------|--------------------|-----------|
| Br⁻ | Base | – | ✓ | ✓ |
| CN⁻ | Base | – | ✓ | ✓ |
| H₂CO₃ | Acid | ✓ | ✓ | ✓ |
| NH₃ | Base | – | ✓ | ✓ |
| HNO₂ | Acid | ✓ | ✓ | ✓ |
| Ba(OH)₂ | Base | ✓ | ✓ | ✓ |
| HCl | Acid | ✓ | ✓ | ✓ |
| AlCl₃ | Acid | – | ✓ | ✓ |
| Cl⁻ | Base | – | ✓ | ✓ |
| KOH | Base | ✓ | ✓ | ✓ |
| IO₃⁻ | Base | – | ✓ | ✓ |
| CH₃COOH | Acid | ✓ | ✓ | ✓ |

Boxed Final Answer:
\[
\boxed{
\begin{array}{l}
\text{Part 1:} \\
\text{a) H⁺ donor: HNO₃, H⁺ acceptor: H₂O} \\
\text{b) H⁺ donor: H₂O, H⁺ acceptor: C₂H₅NH₂} \\
\text{c) H⁺ donor: CH₃COOH, H⁺ acceptor: H₂O} \\
\\
\text{Part 2:} \\
\text{a) HSO₃⁻} \\
\text{b) CO₃²⁻} \\
\text{c) NH₃} \\
\\
\text{Part 3:} \\
\text{a) H₃O⁺} \\
\text{b) HCO₃⁻} \\
\text{c) PH₄⁺} \\
\\
\text{Part 4:} \\
\begin{array}{|c|c|c|c|c|}
\hline
\text{Molecule/Ion} & \text{Acid or Base} & \text{Arrhenius} & \text{Brønsted-Lowry} & \text{Lewis} \\
\hline
\text{Br⁻} & \text{Base} & – & ✓ & ✓ \\
\hline
\text{CN⁻} & \text{Base} & – & ✓ & ✓ \\
\hline
\text{H₂CO₃} & \text{Acid} & ✓ & ✓ & ✓ \\
\hline
\text{NH₃} & \text{Base} & – & ✓ & ✓ \\
\hline
\text{HNO₂} & \text{Acid} & ✓ & ✓ & ✓ \\
\hline
\text{Ba(OH)₂} & \text{Base} & ✓ & ✓ & ✓ \\
\hline
\text{HCl} & \text{Acid} & ✓ & ✓ & ✓ \\
\hline
\text{AlCl₃} & \text{Acid} & – & ✓ & ✓ \\
\hline
\text{Cl⁻} & \text{Base} & – & ✓ & ✓ \\
\hline
\text{KOH} & \text{Base} & ✓ & ✓ & ✓ \\
\hline
\text{IO₃⁻} & \text{Base} & – & ✓ & ✓ \\
\hline
\text{CH₃COOH} & \text{Acid} & ✓ & ✓ & ✓ \\
\hline
\end{array}
\end{array}
}
\]