Pick the stronger base from each pair. c. NO2– or NO3–

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Identify the conjugate acids of each base: NO2– is the conjugate base of HNO2, and NO3– is the conjugate base of HNO3.

Recall that the strength of a base is inversely related to the strength of its conjugate acid. A weaker acid has a stronger conjugate base.

Compare the acid strengths: HNO3 is a strong acid, while HNO2 is a weak acid.

Since HNO3 is a stronger acid than HNO2, its conjugate base (NO3–) is weaker than the conjugate base of HNO2 (NO2–).

Conclude that NO2– is the stronger base compared to NO3–.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Acid-Base Theory

Acid-base theory explains the behavior of acids and bases in chemical reactions. According to the Brønsted-Lowry theory, an acid is a proton donor, while a base is a proton acceptor. Understanding this concept is crucial for determining the strength of bases, as stronger bases are more effective at accepting protons.

Conjugate Acid-Base Pairs

Conjugate acid-base pairs consist of two species that differ by the presence of a proton. For example, when a base accepts a proton, it forms its conjugate acid. In the case of NO2– and NO3–, recognizing their conjugate pairs helps in assessing their relative strengths as bases, as the stability of the conjugate acid influences the base's strength.

Resonance and Stability

Resonance refers to the delocalization of electrons within a molecule, which can stabilize the structure. In the context of NO2– and NO3–, the resonance structures of these anions affect their stability and, consequently, their basicity. A more stable anion is typically a weaker base, as it is less likely to accept a proton.

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