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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 ...
In chemistry, acid value (AV, acid number, neutralization number or acidity) is a number used to quantify the acidity of a given chemical substance.It is the quantity of base (usually potassium hydroxide (KOH)), expressed as milligrams of KOH required to neutralize the acidic constituents in 1 gram of a sample.
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.
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.
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 ...
Two major assumptions are used in this method: The compound vapor behaves as an ideal gas (follows all 5 postulates of the kinetic theory of gases); Either the volume of the vessel does not vary significantly between room temperature and the working temperature, or the volume of the vessel may be accurately determined at the working temperature
Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO 3.Sodium bisulfite is not a real compound, [2] but a mixture of salts that dissolve in water to give solutions composed of sodium and bisulfite ions.