Why Does Sodium Sulfide Dissolve In Water?
Created date: 2019/08/10

While crystal sodium sulfide and barium sulfide are both white powders, the latter one is precipitation while the former one will disappear in the water at once. Why does sodium sulfide dissolve in water so quickly and thoroughly?


Here are the content list

  • Why Does Sodium Sulfide Dissolve Quickly?

  • Why Does Sodium Sulfide Dissolve Thoroughly?

  • How Can We Utilize Sodium Sulfide?


Why Does Sodium Sulfide Dissolve Quickly?

Pure sodium sulfide is a colorless crystalline powder. Strong moisture absorption, soluble in water. The aqueous solution is strongly alkaline. Burns on skin and hair. So it commonly known as alkali sulfide. The same mass of material, powder and solvent contact area is significantly greater than the block, also in the same time there are more molecules and solvent molecules contacting each other, and the shape of sodium sulfide is mostly powder or flake, so the dissolution rate is fast.


Why Does Sodium Sulfide Dissolve Thoroughly?

Hydrogen sulfide dissolves in water to form hydro sulfuric acid, which is a very weak acid, so sodium sulfide is almost completely hydrolyzed in water solution, and hydrogen sulfide and sodium hydroxide are obtained. It is difficult to obtain theoretically saturated solutions of sodium sulfide because hydrolysis is too complete, and sodium hydrogen sulfide is often formed and hydrogen sulfide gas is released.

Sodium sulfide aqueous solution in the air will slowly oxidize into sodium thiosulfate and sodium polysulfide. The main product of oxidation is sodium thiosulfate because of the rapid formation of sodium thiosulfate.

Oxygen and sulfur are in the same group, and since sodium oxide is a very basic oxide, sodium sulfide is a very basic sulfide. Or according to the proton theory, hydrogen sulfide is a weak acid, and its chelating base is a strong base.


How Can We Utilize Sodium Sulfide?

Under the experimental conditions, hs- produced by sodium sulfide hydrolysis competes with xanthate ions adsorbed on the mineral surface to desorption the xanthate ions adsorbed on the mineral surface.

The waste liquid of electroless nickel plating was treated by chemical precipitation method, and the nickel ion of the waste liquid was precipitated out in the form of nickel sulfide with sodium sulfide as precipitant, so as to purify the waste liquid and recover nickel. The results showed that sodium sulfide dosage had the greatest effect, followed by pH value, and reaction time had the least effect. At a pH of 6, 200 mL sodium sulfide solution with a mass fraction of 20% was added, and the reaction time was 30 min. The removal rate of nickel from 200 mL waste electroless nickel plating solution (with a mass concentration of 5,450 mg/L) was 99.8%. The mass concentration of residual nickel could be reduced to about 12 mg/L. At the same time, the precipitate was dense and the nickel content was high (mass fraction was 21.6%), which was convenient for further recycling.

China's annual emissions of SO₂ 2 million tons, causing huge losses, control of SO acid rain pollution has become one of the central tasks of the country. China is a country with coal as its main energy source. Coal accounts for 75% of primary energy, so coal-fired SO2 emissions account for 85% of total SO emissions. There are many flue gas desulfurization technologies, which can be divided into dry, semi-dry and wet methods. This paper introduces the mechanism of sodium sulfide and sulfur wet desulfurization process, and discusses its application. The desulfurization product is pure sulfur, and the intermediate product sodium sulfate can be recycled to sodium sulfide. According to the estimation of material balance, 1.64 tons of SO can be removed per ton of sodium sulfide to produce 0.82 tons of elemental sulfur and 1.82 tons of sodium sulfate. It can be regenerated into sodium sulfide for recycling use according to mature technology. In other words, every ton of SO removed can produce ~0.5 tons of sulfur. Compared with other desulfurization products, sulfur has more uses and is more convenient for storage and transportation.




As with most solutes, the solubility of sodium sulfide increases with temperature, 15.4g/100ml of water at 10 degrees and 57.2g/100ml of water at 90 degrees, so using powder and high temperature is a good idea if you want to improve the solubility of sodium sulfide. For more information, please contact our company Shaanxi Fuhua Chemical Co., Ltd.

Shaanxi Fuhua Tading Co.,. Ltd.

Room 1610, Building A, Haixing City Square, Keji Road,High-tech. Zone, Xian City, Shaanxi, China


2nd Idustial Road East Zhuangi ldutialone Fuping

County, Shaanxi Province, China