Fact Check: Is HNO3 a weak acid?

Is HNO3 a Weak Acid?

Introduction

The claim in question is whether HNO3, or nitric acid, is classified as a weak acid. This inquiry is significant in the field of chemistry, as the classification of acids can affect their applications and behavior in various chemical reactions.

What We Know

1. Classification of HNO3: HNO3 is widely recognized as a strong acid. According to multiple sources, it completely dissociates in water, releasing a significant amount of hydrogen ions (H⁺) and nitrate ions (NO₃⁻) 39.
2. Dissociation in Water: The complete ionization of HNO3 in aqueous solutions is a key characteristic that defines it as a strong acid. This means that in a solution, nearly all HNO3 molecules break apart into ions, contributing to a high concentration of hydrogen ions 9.
3. Comparison with Other Acids: HNO3 is often listed alongside other strong acids such as hydrochloric acid (HCl) and sulfuric acid (H₂SO₄) in educational materials and reference charts 24. This classification is based on the degree of ionization in water, where strong acids fully ionize, while weak acids do not 4.
4. Monoprotic Nature: HNO3 is classified as a monoprotic acid, meaning it can donate only one proton (H⁺) per molecule during dissociation 10. This is a characteristic of many strong acids, which typically donate protons readily.

Analysis

The claim that HNO3 is a weak acid contradicts the consensus in the scientific community. The sources that support the classification of HNO3 as a strong acid are generally reliable, including educational platforms like Chemistry LibreTexts 7 and reputable chemical databases like PubChem 1.

1. Source Reliability:

   • PubChem: A well-established database maintained by the National Center for Biotechnology Information (NCBI), which provides verified chemical information 1.
   • MilliporeSigma: A trusted supplier of laboratory chemicals that provides a comprehensive acid and base chart 2.
   • Chemistry LibreTexts: A widely used educational resource that offers detailed explanations about chemical concepts, including acid-base theory 7.

2. Potential Bias: Some sources, such as blog posts or less formal educational websites, may lack the rigorous peer review that characterizes more authoritative sources. For example, the article from Topblogtenz presents the information in a straightforward manner but lacks citations to primary literature, which could raise questions about its reliability 5.

3. Methodology and Evidence: The classification of acids as strong or weak is based on empirical observations of their behavior in solution. The consensus is that strong acids like HNO3 dissociate completely, while weak acids only partially dissociate. This classification is supported by experimental data and is a foundational concept in chemistry 39.

4. Contradicting Sources: While the majority of sources classify HNO3 as a strong acid, any claims suggesting it is a weak acid would need substantial empirical evidence to be credible. Currently, such claims are not supported by the prevailing scientific literature.

Conclusion

Verdict: False

The claim that HNO3 (nitric acid) is a weak acid is false. The evidence overwhelmingly supports the classification of HNO3 as a strong acid, as it completely dissociates in water, releasing a significant concentration of hydrogen ions. Reliable sources, including established chemical databases and educational platforms, consistently categorize HNO3 alongside other strong acids, reinforcing its classification based on empirical observations of its behavior in solution.

It is important to note that while the consensus is clear, the classification of acids can sometimes be nuanced, depending on specific conditions or contexts. However, in the case of HNO3, the prevailing scientific literature does not support any claims of it being a weak acid.

Readers should also be aware of the limitations in available evidence. While the sources cited are reputable, the discourse surrounding acid classification can evolve, and new findings may emerge. Therefore, it is advisable for readers to critically evaluate information and consult multiple sources when forming conclusions about scientific claims.

Sources

1. PubChem. Nitric Acid | HNO3 | CID 944. Retrieved from PubChem
2. MilliporeSigma. Acid and Base Chart — Table of Acids & Bases. Retrieved from MilliporeSigma
3. Vocab Dictionary. Is HNO3 Classified as a Strong Acid, Weak Acid, Strong Base, or Weak Base? Retrieved from Vocab Dictionary
4. Online Sciences. Classification of Acids according to its strength. Retrieved from Online Sciences
5. Topblogtenz. Is HNO3 an acid or base? Strong vs Weak. Retrieved from Topblogtenz
6. Brainly. Classify each of the following species as a weak or strong acid. Retrieved from Brainly
7. Chemistry LibreTexts. 14.7: Strong and Weak Acids and Bases. Retrieved from Chemistry LibreTexts
8. Studocu. Are the below strong acids weak acids strong base weak base. Retrieved from Studocu
9. Pediabay. Is HNO3 (Nitric Acid) a Strong or Weak Acid? And Why? Retrieved from Pediabay
10. ANSWERTICA. Is HNO3 Monoprotic Diprotic Or Triprotic? Retrieved from ANSWERTICA