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  2. Acidic rock - Wikipedia

    en.wikipedia.org/wiki/Acidic_Rock

    Acidic rock or acid rock refers to the chemical composition of igneous rocks that has 63% wt% SiO 2 content. [1] Rocks described as acidic usually contain more than 20% of free quartz. [2] Typical acidic rocks are granite or rhyolite. The term is used in chemical classification of igneous rock based on the content of silica (SiO 2).

  3. Silicon dioxide - Wikipedia

    en.wikipedia.org/wiki/Silicon_dioxide

    Stishovite does not react to HF to any significant degree. [65] HF is used to remove or pattern silicon dioxide in the semiconductor industry. Silicon dioxide acts as a Lux–Flood acid, being able to react with bases under certain conditions. As it does not contain any hydrogen, non-hydrated silica cannot directly act as a Brønsted–Lowry acid.

  4. Quartz - Wikipedia

    en.wikipedia.org/wiki/Quartz

    Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. [9] Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation ...

  5. Amphoterism - Wikipedia

    en.wikipedia.org/wiki/Amphoterism

    Another possibility is the molecular autoionization reaction between two water molecules, in which one water molecule acts as an acid and another as a base. H 2 O + H 2 O ⇌ H 3 O + + HO −. The bicarbonate ion, HCO − 3, is amphoteric as it can act as either an acid or a base: As an acid, losing a proton: HCO − 3 + OH − ⇌ CO 2− 3 ...

  6. Silicification - Wikipedia

    en.wikipedia.org/wiki/Silicification

    Silicic acid (H 4 SiO 4) in the silica-enriched fluids forms lenticular, nodular, fibrous, or aggregated quartz, opal, or chalcedony that grows within the rock. [5] Silicification happens when rocks or organic materials are in contact with silica-rich surface water, buried under sediments and susceptible to groundwater flow, or buried under ...

  7. Water-reactive substances - Wikipedia

    en.wikipedia.org/wiki/Water-reactive_substances

    Group 1: Alkali metals Reaction of sodium (Na) and water Reaction of potassium (K) in water. The alkali metals (Li, Na, K, Rb, Cs, and Fr) are the most reactive metals in the periodic table - they all react vigorously or even explosively with cold water, resulting in the displacement of hydrogen.

  8. Reactivity series - Wikipedia

    en.wikipedia.org/wiki/Reactivity_series

    reacts with acids and steam Aluminium Al Al 3+ Titanium Ti Ti 4+ reacts with concentrated mineral acids: pyrometallurgical extraction using magnesium, or less commonly other alkali metals, hydrogen or calcium in the Kroll process: Manganese Mn Mn 2+ reacts with acids; very poor reaction with steam smelting with coke: Zinc Zn Zn 2+ Chromium Cr Cr 3+

  9. Fused quartz - Wikipedia

    en.wikipedia.org/wiki/Fused_quartz

    Fused quartz, fused silica or quartz glass is a glass consisting of almost pure silica (silicon dioxide, SiO 2) in amorphous ... except hydrofluoric acid, ...