Label each of the following as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: (a) CH3COO-

Verified step by step guidance

1. Step 1: Identify the given species. In this case, we have CH3COO-, which is the acetate ion.
2. Step 2: Determine the basicity of the given species. The acetate ion is a weak base because it accepts a proton (H+) to form its conjugate acid but does not ionize completely in water.
3. Step 3: Write the formula of its conjugate acid. The conjugate acid of CH3COO- is CH3COOH, which is acetic acid. This is formed when CH3COO- accepts a proton (H+).
4. Step 4: Determine the acidity of the conjugate acid. Acetic acid (CH3COOH) is a weak acid because it donates a proton (H+) but does not ionize completely in water.
5. Step 5: Summarize the findings. CH3COO- is a weak base and its conjugate acid, CH3COOH, is a weak acid.

Key Concepts

Acid-Base Theory

Acid-base theory explains the behavior of acids and bases in chemical reactions. According to the Brønsted-Lowry theory, acids are proton donors, while bases are proton acceptors. Understanding this theory is essential for classifying substances like CH3COO- and determining their conjugate acids.

Conjugate Acid-Base Pairs

A conjugate acid-base pair consists of two species that differ by the presence or absence of a proton (H+). For example, when a base accepts a proton, it forms its conjugate acid. Recognizing these pairs helps in identifying the strength of acids and bases, such as determining the nature of CH3COO- and its conjugate acid, CH3COOH.

Strength of Acids and Bases

The strength of acids and bases is determined by their ability to dissociate in water. Strong acids completely ionize, while weak acids only partially ionize. Similarly, strong bases fully dissociate in solution, whereas weak bases do not. This concept is crucial for classifying CH3COO- and its conjugate acid, CH3COOH, in terms of their basicity and acidity.