Weak Nitric Acid generally refers to diluted nitric acid or a low-concentration nitric acid solution. Nitric acid (HNO₃) is a strong acid, but when diluted with water, it becomes less reactive, and its acidity is reduced. A weak nitric acid solution typically has a concentration of less than 70% HNO₃ by weight, with 5% to 20% concentration being common for industrial, laboratory, and cleaning applications. In contrast, concentrated nitric acid (often around 68-70% HNO₃) is much more aggressive and highly corrosive.
Properties of Weak Nitric Acid:
- Chemical Formula: HNO₃
- Appearance: Colorless to pale yellow (depending on concentration)
- Odor: Pungent, characteristic smell (often associated with oxidizing agents)
- Density: Typically between 1.04 and 1.38 g/cm³ for weaker concentrations
- Boiling Point: About 83°C (181.4°F) for 68% concentration, lower for dilute forms
- Solubility: Completely soluble in water
- pH: The pH of weak nitric acid is typically between 1 and 3, depending on the concentration.
Key Uses of Weak Nitric Acid:
- Laboratory Reagents: Used in various chemical processes, especially for dilution purposes.
- Cleaning: Often used for cleaning metal surfaces and removing scale and oxidation.
- Manufacturing: Used in the production of fertilizers (ammonium nitrate) and explosives.
- Electroplating: Used in metal finishing processes.