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A 0.5 McFarland standard is prepared by mixing 0.05 mL of 1.175% barium chloride dihydrate (BaCl 2 •2H 2 O), with 9.95 mL of 1% sulfuric acid (H 2 SO 4). [ 1 ] Now there are McFarland standards prepared from suspensions of latex particles, which lengthens the shelf life and stability of the suspensions.
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. Similarly, for a ...
The van Urk reagent, which uses 0.125 g of p-DMAB, 0.2 mL of ferric chloride solution (25 mg/mL) in 100 mL of 65% sulfuric acid. [ 9 ] [ 10 ] [ 11 ] This is sometimes referred to as the Hofmann reagent or p-DMAB-TS (Test Solution) and gives slightly different colours with different indoles.
For determining the acid value of mineral oils and biodiesel, there are standard methods such as ASTM D 974 and DIN 51558, and especially for biodiesel the European Standard EN 14104 and ASTM D664 are both widely used worldwide. [2] Acid value of biodiesel should be lower than 0.50 mg KOH/g in both EN 14214 and ASTM D6751 standard fuels.
It is commonly used in the treatment of varicose and spider veins of the leg, during the procedure of sclerotherapy. [2] Being a detergent , its action is on the lipid molecules in the cells of the vein wall, causing inflammatory destruction of the internal lining of the vein and thrombus formation eventually leading to sclerosis of the vein.
Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.
Copper(II) oxide reacts with mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid to give the corresponding hydrated copper(II) salts: [4] CuO + 2 HNO 3 → Cu(NO 3) 2 + H 2 O CuO + 2 HCl → CuCl 2 + H 2 O CuO + H 2 SO 4 → CuSO 4 + H 2 O. In presence of water it reacts with concentrated alkali to form the corresponding ...
56.1 is the molar mass of KOH. [7] 38.049 is the molecular mass of glycerol backbone. For instance, triolein, a triglyceride occurring in many fats and oils, has three oleic acid residues esterified to a molecule of glycerol with a total MW of 885.4 (g / mol). Therefore, its SV equals 190 mg KOH / g sample. [9]