Method 1
Introduction
Hydrogen sulfide gas can be produced by reacting ferrous sulfide with dilute sulfuric acid.
Because ferrous sulfide is an insoluble solid, the reaction does not require heating and can be performed with a device similar to that used in hydrogen production (e.g., a Qipu generator).
If sodium sulfide is used to react with dilute sulfuric acid, the reaction is too violent to be controlled because sodium sulfide is soluble in water. Therefore, it is not used.
Note: The high iron ion in ferric chloride stated in the video below is wrong. The three-valent iron ions contained in ferric chloride should become positive iron, while high iron refers to the six-valent iron, the representative substance is sodium pertechnate, a water purifier.
Principle
Strong non-oxidizing acid reacts with weak acid salt (FeS) to produce hydrogen sulfide (H2S dissolved in water gives weak acid hydrosulfuric acid):
FeS+H2SO4(dilute)=FeSO4+H2S↑;
FeS+2HCl=FeCl2+H2S↑.
Hydrogen sulfide dissolves in water to form hydrosulfuric acid, so it cannot be collected by drainage. Because hydrogen sulfide is denser than air, it can be collected by the exhaust air collection method with the mouth of the bottle upward.
Supplies
Kip generator or simple gas generator, gas collection bottle, glass slides, FeS, dilute hydrochloric acid (or dilute H2SO4) solution, lead acetate test paper.
Operation
To make H2S you can use a kep generator or a simple device for making the gas. Put FeS into the spherical body of the Qipu generator, and fill the funnel with dilute HCl. When H2S is needed, open the piston of the gas conduit, and FeS and dilute HCl come into contact to produce H2S, and when you stop using the gas, you only need to close the piston to stop the reaction.
Use test paper dipped in lead acetate (or lead nitrate) solution, placed in the mouth of the cylinder to test, if the paper turns black is proof that the cylinder is full of H2S gas:
Drying
Concentrated sulfuric acid can not be used (remember), and can not be used to use alkaline desiccant (eg, soda lime).
Phosphorus pentoxide or anhydrous calcium chloride can be used to dry hydrogen sulfide gas.
Remarks
The ferrous sulfide used should be newly acquired; if it is stored for too long, both Fe and S in FeS will be oxidized, thus affecting the experiment.
The ferrous sulfide put into the gas generator should be smashed into chunks the size of a broad bean grain.
Concentrated hydrochloric acid cannot be used because it volatilizes hydrogen chloride, making the hydrogen sulfide impure.
Can not use HNO3 or concentrated H2SO4, because they are oxidizing acid, and FeS redox reaction, but can not produce hydrogen sulfide: 2FeS + 8H2SO4 (concentrated) = Fe2 (SO4) 3 + 5SO2 ↑ + 2S ↓ + 8H2O; FeS + 8HNO3 (concentrated) = Fe (NO3) 3 + 5NO2 ↑ + S ↓ + 4H2O ?[3]?
H2S is toxic, the experiment should pay attention to ventilation, excess H2S should be promptly passed into the NaOH solution (or metal salt solution) for absorption.
Mnemonic
Ferrous sulfide dilute acid meet, Qipu apparatus in the gas born.
Cabinet operation on the exhaust, oxidizing acids are not used.
Explanation:
1, ferrous sulfide dilute acid, qipu in the gas born: "dilute acid" here refers to dilute hydrochloric acid or dilute sulfuric acid. The meaning of this sentence is that in the laboratory commonly used ferrous sulfide (FeS) and dilute hydrochloric acid (HCl) or dilute sulfuric acid (H2SO4), in the Qipu generator reaction to produce hydrogen sulfide (H2S).
2, the cabinet operation on the exhaust: "cabinet" refers to the fume hood. "Closet operation" means that the procedure must be carried out in a fume hood. "Upper exhaust" means that the collection of H2S by upward exhaust air collection method, because H2S is soluble in water, and the density is greater than air.
3, oxidizing acid is not used: "oxidizing acid" here refers to concentrated sulfuric acid (H2SO4) and nitric acid (HNO3). The meaning of this sentence is that no oxidizing acid and ferrous sulfide reaction to produce hydrogen sulfide, because hydrogen sulfide is a strong reductant, easily oxidized by oxidizing acid.? [4]? Also, concentrated sulfuric acid cannot be used as a desiccant.
Method 2
The 20% to 30% phosphoric acid is slowly dripped from a dispensing funnel into a concentrated aqueous solution of Na2S-9H2O, and the resulting gas is dried by anhydrous calcium chloride and phosphorus pentoxide to produce hydrogen sulfide gas, which is liquefied and pressed into a cylinder.? [1]?
Method 3
Hydrogen sulfide is produced by direct synthesis of sulfur and hydrogen purity of high purity hydrogen under reduced pressure into the dryer for further purification, and then by metering into the bottom of the reactor and sulfur yellow direct contact reaction, generating hydrogen sulfide, hydrogen sulfide is washed by the scrubber, and then into the sulfur vapor condenser will be among the remaining sulfur vapors condensed down. The pure hydrogen sulfide gas is compressed by a press and enters the hydrogen sulfide condenser, and the liquid hydrogen sulfide is collected in a storage tank.? [1]?
The reaction apparatus for preparing liquid hydrogen sulfide from calcium sulfide by reacting it with magnesium chloride is shown in the figure, and all operations should be carried out in a fume hood.? [1]?
The apparatus for the preparation of hydrogen sulfide? [1]
Please click to enter image description
A is a flask placed in a water bath; B, C, D, E, and F are 250 mL glass flasks containing water, saturated Ba(OH)2 (outside in a cold bath with ice salts), calcium chloride, phosphorus pentoxide, and glass wool (outside cooled with dry ice); G is a 50 mL test tube with a Dewar's flask of dry-ice ether cryogen; H is a mercury seal ; I is the outlet. [1]?
The generator flask A was filled with 500 mL of saturated magnesium chloride solution and 10 g of solid magnesium chloride and 50 g of good quality calcium sulfide were added. Hydrogen sulfide gas can be produced smoothly and continuously when the mixture is heated to 60°C. Hydrogen sulfide can be passed through after barium hydroxide in bottle C absorbs the initially produced hydrogen sulfide and transforms it into barium sulfide hydride, while other volatile acidic impurities are absorbed. The gas can be kept from passing through the mercury seal H until the air is exhausted from the system to speed up the process of exhausting the air. After the reaction has been going on for some time liquid hydrogen sulfide coalesces in test tube G.? [1]?
Method 4
Hydrolysis of Aluminum Sulfide: A suitable amount of aluminum sulfide solid is placed in a flask, and water is slowly dripped into it from a dropping funnel, which produces a very pure hydrogen sulfide gas without difficulty.? [1]