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For example, sulfuric acid (H 2 SO 4) is a diprotic acid. Since only 0.5 mol of H 2 SO 4 are needed to neutralize 1 mol of OH −, the equivalence factor is: f eq (H 2 SO 4) = 0.5. If the concentration of a sulfuric acid solution is c(H 2 SO 4) = 1 mol/L, then its normality is 2 N. It can also be called a "2 normal" solution.
Akin to its use for pickling, hydrochloric acid is used to dissolve many metals, metal oxides and metal carbonates. The conversions are often depicted in simplified equations: Zn + 2 HCl → ZnCl 2 + H 2 NiO + 2 HCl → NiCl 2 + H 2 O CaCO 3 + 2 HCl → CaCl 2 + CO 2 + H 2 O. These processes are used to produce metal chlorides for analysis or ...
A more convenient laboratory method involves the (reversible) dehydration of nitrous acid by HCl [4] HNO 2 + HCl → H 2 O + NOCl. By the direct combination of chlorine and nitric oxide; This reaction reverses above 100 °C. Cl 2 + 2 NO → 2 NOCl. By reduction of nitrogen dioxide with hydrogen chloride: [5] 2NO 2 + 4 HCl → 2NOCl + 2H 2 O + Cl 2
Limescale build-up inside a pipe reduces both liquid flow and thermal conduction from the pipe, so will reduce thermal efficiency when used as a heat exchanger.. A descaling agent or chemical descaler is a liquid chemical substance used to remove limescale from metal surfaces in contact with hot water, such as in boilers, water heaters, and kettles.
Caffeine (1,3,7-trimethylxanthine) is the alkaloid most present in green and roasted coffee beans. The content of caffeine is between 1.0% and 2.5% by weight of dry green coffee beans. The content of caffeine does not change during maturation of green coffee beans, but higher caffeine content is found in plants grown at higher altitudes.
Contrary to popular belief, they don't mean that all but 1% or 2% of the fat has been removed. Rather they refer to what percentage of the total weight is milk fat. For example, one cup of milk ...
For example, the atomic percent of hydrogen in water (H 2 O) is at.% H 2 O = 2/3 x 100 ≈ 66.67%, while the atomic ratio of hydrogen to oxygen is A H:O = 2:1. Isotopes
Another method which can be used to produce solutions up to 10% concentration is by the use of cation exchange resins and a soluble salt such as NaClO 3, where the Na+ cation will exchange with H+. [2] Another method is the heating of hypochlorous acid, producing chloric acid and hydrogen chloride: [citation needed] 3 HClO → HClO 3 + 2 HCl