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  2. Sulfurous acid - Wikipedia

    en.wikipedia.org/wiki/Sulfurous_acid

    Sulfuric(IV) acid (United Kingdom spelling: sulphuric(IV) acid), also known as sulfurous (UK: sulphurous) acid and thionic acid, [citation needed] is the chemical compound with the formula H 2 SO 3. Raman spectra of solutions of sulfur dioxide in water show only signals due to the SO 2 molecule and the bisulfite ion, HSO − 3 . [ 2 ]

  3. Gas evolution reaction - Wikipedia

    en.wikipedia.org/wiki/Gas_evolution_reaction

    A replacement reaction concerning zinc metal and dilute sulfuric acid. + + In this example, diatomic hydrogen gas is released. Dilute hydrochloric acid can be used in place of dilute sulfuric acid.

  4. Standard enthalpy of formation - Wikipedia

    en.wikipedia.org/wiki/Standard_enthalpy_of_formation

    For many substances, the formation reaction may be considered as the sum of a number of simpler reactions, either real or fictitious. The enthalpy of reaction can then be analyzed by applying Hess' law, which states that the sum of the enthalpy changes for a number of individual reaction steps equals the enthalpy change of the overall reaction.

  5. Contact process - Wikipedia

    en.wikipedia.org/wiki/Contact_process

    The contact process is a method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum was originally used as the catalyst for this reaction; however, because it is susceptible to reacting with arsenic impurities in the sulfur feedstock, vanadium(V) oxide (V 2 O 5) has since been preferred.

  6. Ammonium sulfate - Wikipedia

    en.wikipedia.org/wiki/Ammonium_sulfate

    2 NH 3 + H 2 SO 4 → (NH 4) 2 SO 4. A mixture of ammonia gas and water vapor is introduced into a reactor that contains a saturated solution of ammonium sulfate and about 2% to 4% of free sulfuric acid at 60 °C. Concentrated sulfuric acid is added to keep the solution acidic, and to retain its level of free acid.

  7. Piranha solution - Wikipedia

    en.wikipedia.org/wiki/Piranha_solution

    Piranha solution, also known as piranha etch, is a mixture of sulfuric acid (H 2 SO 4) and hydrogen peroxide (H 2 O 2). The resulting mixture is used to clean organic residues off substrates , for example silicon wafers . [ 1 ]

  8. Standard Gibbs free energy of formation - Wikipedia

    en.wikipedia.org/wiki/Standard_Gibbs_free_energy...

    The standard Gibbs free energy of formation (G f °) of a compound is the change of Gibbs free energy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 bar of pressure and the specified temperature, usually 298.15 K or 25 °C).

  9. Stoichiometry - Wikipedia

    en.wikipedia.org/wiki/Stoichiometry

    Fe 2 O 3 + 2 Al → Al 2 O 3 + 2 Fe This equation shows that 1 mole of iron(III) oxide and 2 moles of aluminum will produce 1 mole of aluminium oxide and 2 moles of iron . So, to completely react with 85.0 g of iron(III) oxide (0.532 mol), 28.7 g (1.06 mol) of aluminium are needed.