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  2. Kjeldahl method - Wikipedia

    en.wikipedia.org/wiki/Kjeldahl_method

    The sample solution is then distilled with a small amount of sodium hydroxide (NaOH). [3] NaOH can also be added with a dropping funnel. [4] NaOH reacts the ammonium (NH 4 +) to ammonia (NH 3), which boils off the sample solution. Ammonia bubbles through the standard acid solution and reacts back to ammonium salts with the weak or strong acid. [3]

  3. Nitrous acid - Wikipedia

    en.wikipedia.org/wiki/Nitrous_acid

    The acidification is usually conducted at ice temperatures, and the HNO 2 consumed in situ. [6] [7] Nitrous acid equilibrates with dinitrogen trioxide in water, so that concentrated solutions are visibly blue: [4]: 2 N 2 O 3 + H 2 O ⇌ 2 HNO 2. Addition of dinitrogen trioxide to water is thus another preparatory technique.

  4. Nitric acid - Wikipedia

    en.wikipedia.org/wiki/Nitric_acid

    HNO 3 + 2 H 2 SO 4 ⇌ [NO 2] + + [H 3 O] + + 2 HSO − 4; Equilibrium constant: K ≈ 22. The nitronium ion, [NO 2] +, is the active reagent in aromatic nitration reactions. Since nitric acid has both acidic and basic properties, it can undergo an autoprotolysis reaction, similar to the self-ionization of water: 2 HNO 3 ⇌ [NO 2] + + NO − 3 ...

  5. Ammonium nitrate - Wikipedia

    en.wikipedia.org/wiki/Ammonium_nitrate

    As ammonium nitrate is a salt, both the cation, NH + 4, and the anion, NO − 3, may take part in chemical reactions. Solid ammonium nitrate decomposes on heating. At temperatures below around 300 °C, the decomposition mainly produces nitrous oxide and water: NH 4 NO 3 → N 2 O + 2 H 2 O. At higher temperatures, the following reaction ...

  6. Solubility chart - Wikipedia

    en.wikipedia.org/wiki/Solubility_chart

    The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.

  7. Nitrite - Wikipedia

    en.wikipedia.org/wiki/Nitrite

    HNO 2 ⇌ H + + NO − 2; pK a ≈ 3.3 at 18 °C [3] Nitrous acid is also highly unstable, tending to disproportionate: 3 HNO 2 (aq) ⇌ H 3 O + + NO − 3 + 2 NO. This reaction is slow at 0 °C. [2] Addition of acid to a solution of a nitrite in the presence of a reducing agent, such as iron(II), is a way to make nitric oxide (NO) in the ...

  8. Enthalpy change of solution - Wikipedia

    en.wikipedia.org/wiki/Enthalpy_change_of_solution

    The energy released by the solvation of the ammonium ions and nitrate ions is less than the energy absorbed in breaking up the ammonium nitrate ionic lattice and the attractions between water molecules. Dissolving potassium hydroxide is exothermic, as more energy is released during solvation than is used in breaking up the solute and solvent.

  9. Neutralization (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Neutralization_(chemistry)

    For example, sodium hydroxide, NaOH, is a strong base. NaOH(aq) → Na + (aq) + OH − (aq) Therefore, when a strong acid reacts with a strong base the neutralization reaction can be written as H + + OH − → H 2 O. For example, in the reaction between hydrochloric acid and sodium hydroxide the sodium and chloride ions, Na + and Cl − take ...