What Is Magnesium Oxide?

Magnesium oxide (chemical formula: MgO) is an oxide of magnesium, an ionic compound. A white solid at room temperature. Magnesium oxide exists in nature in the form of periclase and is the raw material for magnesium smelting.

Magnesium oxide is commonly called bitter soil, also called magnesia. Magnesium oxide is

Category: points

The domestic annual output of magnesium oxide is about 12 million tons.

It measures sulfur and arsenic in coal and pyrite and steel. Used as

Method name:

Determination of magnesium oxide-neutralization titration

Application:

This method uses titration to determine the content of magnesium oxide.

This method is suitable for magnesium oxide.

Method principle:

For the test product, add the sulfuric acid titration solution (0.5mol / L) to dissolve, add the methyl orange indicator solution, titrate with sodium hydroxide titration solution (1mol / L), read out the amount of sodium hydroxide titration solution, calculate, Got.

Reagent:

Water (newly boiled to room temperature)

Sodium hydroxide titration solution (0.1mol / L)

Sulfuric acid titration solution (0.5mol / L)

Methyl orange indicator liquid

Reference potassium hydrogen phthalate

equipment:

Sample preparation:

Sodium hydroxide titration solution (0.1mol / L)

Preparation: Take 56mL of clear saturated sodium hydroxide solution, add fresh boiling cold water to make 1000mL.

Calibration: Take about 6.0g of standard potassium hydrogen phthalate dried to constant weight at 105 , accurately weigh, add 50mL of freshly boiled cold water, shake it to make it dissolve as much as possible; add 2 drops of phenolphthalein indicator solution, use When this solution is titrated, when the end point is reached, potassium hydrogen phthalate should be completely dissolved and titrated until the solution becomes pink. Each 1mL of sodium hydroxide titration solution (1mol / L) is equivalent to 204.2mg of potassium hydrogen phthalate. Calculate the concentration of this solution based on the consumption of this solution and the amount of potassium hydrogen phthalate taken.

Storage: Put it in a polyethylene plastic bottle and keep it in a sealed container. There are 2 holes in the plug. One glass tube is inserted into the hole. One tube is connected to the soda lime tube. One tube is used to suck out the liquid.

Sulfuric acid titration solution (0.5mol / L)

Preparation: Take 30mL of sulfuric acid, slowly inject an appropriate amount of water, cool to room temperature, add water to dilute to 1000mL, and shake well.

Calibration: Take about 1.5g of constant anhydrous standard sodium carbonate dried at 270 300 , accurately weigh, add 50mL of water to dissolve, add 10 drops of methyl red-bromocresol green mixed indicator liquid, titrate with this liquid to When the solution changes from green to purplish red, boil for 2 minutes, cool to room temperature, and continue titration until the solution turns green to dark purple. Each 1mL of sulfuric acid titration solution (0.5mol / L) is equivalent to 53.00mg of anhydrous sodium carbonate. Calculate the concentration of the solution according to the consumption of the solution and the amount of anhydrous sodium carbonate taken, that is, obtained.

Methyl orange indicator liquid

Take 0.1g of methyl orange, add 100mL of water to dissolve, and get.

Steps:

Accurately weigh 0.5g of the test sample, add 30mL of sulfuric acid titration solution (0.5mol / L), and add 1 drop of methyl orange indicator solution. Titrate with sodium hydroxide titration solution (1mol / L), read the hydroxide The amount of sodium titration solution used, calculated, each 1mL of sulfuric acid titration solution (0.5 mol / L) is equivalent to 20.15mg of magnesium oxide or 28.04mg of calcium oxide ^[2] .

Note 1: "Precise weighing" means that the weighed weight should be accurate to one thousandth of the weighed weight. "Precision weighing" means that the accuracy of the measured volume should conform to the national standard for the volume of the pipette. Precision requirements.

Note 2: "Determination of moisture" uses the drying method, taking 2 to 5 g of the test sample, and spreading it in a flat weighing bottle that is dry to constant weight, the thickness is not more than 5 mm, and the loose test sample is not more than 10 mm. Open the bottle cap and dry it at 100 105 for 5 hours. Place the cap on the dryer, cool it for 30 minutes, and weigh it precisely. Then dry it at the above temperature for 1 hour, cool it, and weigh it twice. The difference in weighing does not exceed 5 mg. Calculate the moisture content (%) in the test product based on the weight lost.