Kipp's apparatus, also called Kipp generator, is an apparatus designed for preparation of small volumes of

gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

es. It was invented around 1844 by the Dutch pharmacist

Petrus Jacobus Kipp Petrus Jacobus Kipp (Utrecht, 5 March 1808 – Delft, 3 February 1864) was a Dutch apothecary, chemist and instrument maker. He became known as the inventor of the Kipp apparatus, chemistry equipment for the development of gases. Biograph ...

and widely used in chemical

laboratories A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physici ...

and for demonstrations in schools into the second half of the 20th century. It later fell out of use, at least in laboratories, because most gases then became available in small gas cylinders. These industrial gases are much purer and drier than those initially obtained from a Kipp apparatus without further processing.

Design and operation

The apparatus is usually made of

glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching ...

, or sometimes of

polyethylene Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including b ...

, and consists of three vertically stacked chambers, roughly resembling a snowman. The upper chamber extends downward as a tube that passes through the middle chamber into the lower chamber. There is no direct path between the middle and upper chambers, but the middle chamber is separated from the lower chamber by a retention plate, such as a conical piece of glass with small holes, which permits the passage of liquid and gas. The solid material (e.g., iron sulfide) is placed into the middle chamber in lumps sufficiently large to avoid falling through the retention plate. The liquid, such as an acid, is poured into the top chamber. Although the acid is free to flow down through the tube into the bottom chamber, it is prevented from rising there by the pressure of the gas contained above it, which is able to leave the apparatus only by a stopcock near the top of the middle chamber. This stopcock may be opened, initially to permit the air to leave the apparatus, allowing the liquid in the bottom chamber to rise through the retention plate into the middle chamber and react with the solid material. Gas is evolved from this reaction, which may be drawn off through the stopcock as desired. When the stopcock is closed, the pressure of the evolved gas in the middle chamber rises and pushes the acid back down into the bottom chamber, until it is not in contact with the solid material anymore. At that point the chemical reaction comes to a stop, until the stopcock is opened again and more gas is drawn off. Kipp generators only work properly in the described manner if the solid material is insoluble in the acid, as otherwise the dissolved material would continue to evolve gas even after the level dropped. The produced gas often requires further purification and/or drying, due to content of water vapor and possibly mist if the reaction is vigorous.

Examples for prepared gases and their educts

For successful use in a Kipp's apparatus, the solid material has to be available in lumps large enough to stay on the retention plate without falling through its holes. *

Hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

from

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

flakes or

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

and

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid Acid strength is the tendency of an acid, symbol ...

or diluted sulfuric acid respectively. *

Carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

from pieces of

marble Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorphose ...

( calcium carbonate) and hydrochloric acid * Hydrogen sulfide from

iron(II) sulfide Iron(II) sulfide or ferrous sulfide (Br.E. sulphide) is one of a family chemical compounds and minerals with the approximate formula . Iron sulfides are often iron-deficient non-stoichiometric. All are black, water-insoluble solids. Preparatio ...

and hydrochloric acid * Acetylene from

calcium carbide Calcium carbide, also known as calcium acetylide, is a chemical compound with the chemical formula of Ca C2. Its main use industrially is in the production of acetylene and calcium cyanamide. The pure material is colorless, while pieces of te ...

and

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

Methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...

from

aluminium carbide Aluminum carbide, chemical formula Al4 C3, is a carbide of aluminum. It has the appearance of pale yellow to brown crystals. It is stable up to 1400 °C. It decomposes in water with the production of methane. Structure Aluminum carbide has ...

and lukewarm water,

deuterated Isotopic labeling (or isotopic labelling) is a technique used to track the passage of an isotope (an atom with a detectable variation in neutron count) through a reaction, metabolic pathway, or cell. The reactant is 'labeled' by replacing specific ...

methane (CD₄) from aluminium carbide and heavy water *

Chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

from

potassium permanganate Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, that dissolves in water as K+ and , an intensely pink to purple solution. Potassium permanganate is widely used in the c ...

, calcium hypochlorite, or manganese dioxide and hydrochloric acid; also from barium ferrate and hydrochloric acid *

Oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

from calcium hypochlorite and

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

with a bit of

nitric acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...

; also from barium ferrate and dilute sulfuric acid *

Ozone Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...

from

barium peroxide Barium peroxide is the inorganic compound with the formula Ba O2. This white solid (gray when impure) is one of the most common inorganic peroxides, and it was the first peroxide compound discovered. Being an oxidizer and giving a vivid green c ...

and concentrated sulfuric acid * Nitric oxide from

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

turnings and diluted nitric acid *

Nitrogen dioxide Nitrogen dioxide is a chemical compound with the formula . It is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the productio ...

from

turnings and concentrated nitric acid *

Ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...

from magnesium nitride and water, deuterated ammonia when heavy water is used; also from

calcium oxide Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term "''lime''" connotes calcium-containing inorganic ...

and solution of ammonium chloride *

Carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

from

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular v ...

impregnated with oxalic acid and concentrated sulfuric acid * Sulfur dioxide from pumice impregnated with

sodium metabisulfite Sodium metabisulfite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na2S2O5. The substance is sometimes referred to as disodium metabisulfite. It is used a ...

(or sufficiently large pieces of sodium metabisulfite) and concentrated sulfuric acid, or from sodium hydrogen sulphite and concentrated sulfuric acid *

Hydrogen chloride The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride ga ...

can be prepared from lumps of ammonium chloride and concentrated sulfuric acid Generally, weak acidic gases can be released from their metal salts by dilute acids, and sometimes just with water: * Hydrogen sulfide from metal sulfides *

Hydrogen selenide Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic sel ...

from

selenide A selenide is a chemical compound containing a selenium anion with oxidation number of −2 (Se2−), much as sulfur does in a sulfide. The chemistry of the selenides and sulfides is similar. Similar to sulfide, in aqueous solution, the selenide ion ...

s, e.g.

aluminium selenide Aluminium selenide is the inorganic compound with the formula Al2 Se3. Preparation It is a solid prepared by igniting a mixture of the elements at : :2 Al + 3 Se → Al2Se3 The pure compound is white, but typical samples are coloured. Sa ...

Hydrogen telluride Hydrogen telluride is the inorganic compound with the formula H2 Te. A hydrogen chalcogenide and the simplest hydride of tellurium, it is a colorless gas. Although unstable in ambient air, the gas can exist at very low concentrations long enough ...

from tellurides, e.g. aluminium telluride * Some hydrocarbons can be prepared from certain

carbide In chemistry, a carbide usually describes a compound composed of carbon and a metal. In metallurgy, carbiding or carburizing is the process for producing carbide coatings on a metal piece. Interstitial / Metallic carbides The carbides of th ...

s ** Methane from methanides ** acetylene from acetylides **

Methylacetylene Propyne (methylacetylene) is an alkyne with the chemical formula . It is a component of MAPD gas—along with its isomer propadiene (allene), which was commonly used in gas welding. Unlike acetylene, propyne can be safely condensed.Peter P� ...

and

propadiene Propadiene () or allene () is the organic compound with the formula . It is the simplest allene, i.e. a compound with two adjacent carbon double bonds. As a constituent of MAPP gas, it has been used as a fuel for specialized welding. Production ...

from sesquicarbides, e.g. magnesium carbide * Ammonia from certain

nitride In chemistry, a nitride is an inorganic compound of nitrogen. The "nitride" anion, N3- ion, is very elusive but compounds of nitride are numerous, although rarely naturally occuring. Some nitrides have a find applications, such as wear-resistant ...

s, e.g. magnesium nitride *

Phosphine Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...

from

phosphide In chemistry, a phosphide is a compound containing the ion or its equivalent. Many different phosphides are known, with widely differing structures. Most commonly encountered on the binary phosphides, i.e. those materials consisting only of phos ...

s, e.g.

calcium phosphide Calcium phosphide (CP) is the inorganic compound with the formula Ca3P2. It is one of several phosphides of calcium, being described as the salt-like material composed of Ca2+ and P3−. Other, more exotic calcium phosphides have the formula CaP, ...

(often produced together with small amount of

diphosphane Diphosphane, or diphosphine, is an inorganic compound with the chemical formula P2H4. This colourless liquid is one of several binary phosphorus hydrides. It is the impurity that typically causes samples of phosphine to ignite in air. Propert ...

) *

Arsine Arsine (IUPAC name: arsane) is an inorganic compound with the formula As H3. This flammable, pyrophoric, and highly toxic pnictogen hydride gas is one of the simplest compounds of arsenic. Despite its lethality, it finds some applications in ...

from

arsenide In chemistry, an arsenide is a compound of arsenic with a less electronegative element or elements. Many metals form binary compounds containing arsenic, and these are called arsenides. They exist with many stoichiometries, and in this respect a ...

s, e.g.

zinc arsenide Zinc arsenide (Zn3As2) is a binary compound of zinc with arsenic which forms gray tetragonal crystals. It is an inorganic semiconductor with a band gap of 1.0 eV. Synthesis and reactions Zinc arsenide can be prepared by the reaction of zinc with ...

* Stibine from

antimonide Antimonides (sometimes called stibnides) are compounds of antimony with more electropositive elements. The antimonide ion is Sb3−. Reduction of antimony by alkali metals or by other methods leads to alkali metal antimonides of various types. K ...

s, e.g. magnesium antimonide *

Silane Silane is an inorganic compound with chemical formula, . It is a colourless, pyrophoric, toxic gas with a sharp, repulsive smell, somewhat similar to that of acetic acid. Silane is of practical interest as a precursor to elemental silicon. Sila ...

s from some

silicide A silicide is a type of chemical compound that combines silicon and a (usually) more electropositive element. Silicon is more electropositive than carbon. Silicides are structurally closer to borides than to carbides. Similar to borides and carb ...

s (analogue of hydrocarbons, with number of silicon atoms corresponding to the silicide anion structure, sometimes more are produced from the same compound; e.g. silane,

disilane Disilane is a chemical compound with chemical formula Si2H6 that was identified in 1902 by Henri Moissan and Samuel Smiles (1877–1953). Moissan and Smiles reported disilane as being among the products formed by the action of dilute acids on meta ...

and

trisilane Trisilane is the silane with the formula H2Si(SiH3)2. A liquid at standard temperature and pressure, it is a silicon analogue of propane. The contrast with propane however trisilane ignites spontaneously in air. Synthesis Trisilane was characte ...

from decomposition of

magnesium silicide Magnesium silicide, Mg2Si, is an inorganic compound consisting of magnesium and silicon. As-grown Mg2Si usually forms black crystals; they are semiconductors with n-type conductivity and have potential applications in thermoelectric generators. C ...

) * Germanes from germanides, e.g. magnesium germanide *

Stannane Stannane or tin hydride is an inorganic compound with the chemical formula . It is a colourless gas and the tin analogue of methane. Stannane can be prepared by the reaction of and . : Stannane decomposes slowly at room temperature to give ...

s from stannides, e.g. magnesium stannide *

Borane Trihydridoboron, also known as borane or borine, is an unstable and highly reactive molecule with the chemical formula . The preparation of borane carbonyl, BH3(CO), played an important role in exploring the chemistry of boranes, as it indicated ...

s from

boride A boride is a compound between boron and a less electronegative element, for example silicon boride (SiB3 and SiB6). The borides are a very large group of compounds that are generally high melting and are covalent more than ionic in nature. Some bo ...

s (e.g.

tetraborane Tetraborane (systematically named ''arachno''-tetraborane(10)) was the first boron hydride compound to be classified by Stock and Messenez in 1912 and was first isolated by Alfred Stock. It has a relatively low boiling point at 18 °C and is ...

from

magnesium boride Magnesium diboride is the inorganic compound with the formula MgB2. It is a dark gray, water-insoluble solid. The compound has attracted attention because it becomes superconductor, superconducting at 39 K (−234 °C). In terms of its ...

, aluminium boride, or

beryllium boride Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form mi ...

and an acid) * Hydrogen fluoride can be made from concentrated sulfuric acid and e.g.

calcium fluoride Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF2. It is a white insoluble solid. It occurs as the mineral fluorite (also called fluorspar), which is often deeply coloured owing to impurities. ...

Hydrogen bromide Hydrogen bromide is the inorganic compound with the formula . It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room tempe ...

can be prepared from

bromide A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...

s with concentrated

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...

(conc. sulfuric acid is too oxidizing) A version of the apparatus can be used for reaction between two liquid precursors. A mercury trap has to be added as a check valve, and the middle bulb is filled with an inert porous material, e.g.

, onto which one of the precursors is dropped. *

is prepared from hydrochloric acid and concentrated sulfuric acid * Hydrogen sulfide from concentrated sodium sulfide solution and diluted sulfuric acid * Sulfur dioxide from 40% solution of

and concentrated sulfuric acid * Nitric oxide from

ferrous chloride Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2. It is a paramagnetic solid with a high melting point. The compound is white, but typical samples are often off-white. FeCl2 crystallizes from water as ...

in hydrochloric acid and 20% solution of

sodium nitrite Sodium nitrite is an inorganic compound with the chemical formula NaNO2. It is a white to slightly yellowish crystalline powder that is very soluble in water and is hygroscopic. From an industrial perspective, it is the most important nitrite ...

Dinitrogen trioxide Dinitrogen trioxide is the chemical compound with the formula N2O3. It is one of the simple nitrogen oxides. It forms upon mixing equal parts of nitric oxide and nitrogen dioxide and cooling the mixture below −21 °C (−6 °F): :NO + ...

, aka nitrous anhydride, from 20% solution of sodium nitrite and concentrated sulfuric acid *

, from concentrated formic acid and concentrated sulfuric acid.

Further gas treatments

The prepared gas is usually impure, contaminated with fine aerosol of the reagents and water vapor. The gases may need to be filtered, washed and dried before further use. Hydrogen can be washed from sulfane, arsine and oxygen with subsequent bubbling through solutions of

lead acetate Lead acetate can refer to: * Lead subacetate (Basic lead acetate), Pb3(OH)4(CH3COO)2 * Lead(IV) acetate Lead(IV) acetate or lead tetraacetate is an organometallic compound with chemical formula . It is a colorless solid that is soluble in nonpo ...

silver nitrate Silver nitrate is an inorganic compound with chemical formula . It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called ''lunar causti ...

, and alkaline

pyrogallic acid Pyrogallol is an organic compound with the formula C6H3(OH)3. It is a water-soluble, white solid although samples are typically brownish because of its sensitivity toward oxygen. It is one of three isomers of benzenetriols. Production and reac ...

. Acidic gases (e.g. hydrogen sulfide, hydrogen chloride, sulfur dioxide) can be dried with concentrated sulfuric acid, or with

phosphorus pentoxide Phosphorus pentoxide is a chemical compound with molecular formula P4 O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant and dehydra ...

. Basic gases (e.g. ammonia) can be dried with

, sodium hydroxide or

soda lime Soda lime is a mixture of NaOH and CaO chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent ...

. Disposal of the gases can be done by burning the flammable ones (carbon monoxide, hydrogen, hydrocarbons), absorbing them in water (ammonia, hydrogen sulfide, sulfur dioxide, chlorine), or reacting them with a suitable reagent.

Variants

Many variants of the gas production apparatus exist. Some are suitable for production of larger amounts of gases (Gay-Lussac and Verkhovsky), some for smaller amounts (Kiryushkin, U-tube). A

Döbereiner's lamp Döbereiner's lamp, also called a "tinderbox" ("Feuerzeug"), is a lighter invented in 1823 by the German chemist Johann Wolfgang Döbereiner. The lighter is based on the Fürstenberger lighter (invented in Basel in 1780; in which hydrogen gas is ...

is a small modified Kipp's apparatus for production of hydrogen. The hydrogen is led over a platinum sponge

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

, where it reacts with air oxygen, heats the catalyst and ignites from it, producing a gentle flame. It was commercialized for lighting fires and pipes. It's said that in 1820s over a million of the "tinderboxes" ("Feuerzeug") was sold.

References

External links

Demonstration of Kipp's apparatus
at

The Periodic Table of Videos ''Periodic Videos'' (also known as ''The Periodic Table of Videos'') is a video project and YouTube channel on chemistry. It consists of a series of videos about chemical elements and the periodic table, with additional videos on other topics i ...

{{Laboratory equipment Laboratory equipment Dutch inventions Industrial gases

Design and operation

Examples for prepared gases and their educts

Further gas treatments

Variants

Further reading

References

External links