See also:

• CATALYSIS (from the Gr. Kara, down, and Meta, to loosen)

CATALYSIS (from the Gr. Kara, down, and See also:

• META

Meta, to loosen)  , in See also:

• CHEMISTRY
• CHEMISTRY (formerly "chymistry"; Gr. xvµela; for derivation see ALCHEMY)

chemistry, the name given to chemical actions brought about by a substance,. termed the " catalyst," which is recovered unchanged after the See also:

• ACTION

action . The See also:

• TERM

term was introduced by See also:

• BERZELIUS, JONS JAKOB (1779-1848)

Berzelius, who first studied such reactions . It is convenient to See also:

• DIVIDE

divide catalytic actions into two See also:

• GROUPS
• GROUPS, THEORY

groups:—(1) when the catalyst first combines with one of the reaction components to See also:

• FORM (Lat. forma)

form a See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound which immediately reacts with the other components, the catalyst being simultaneously liberated, and See also:

• FREE

free to react with more of the undecomposed first component; and (2), when the catalyst apparently reacts by See also:

• MERE
• MERE, ADALBERT (1838-1909)

mere contact . The theory of See also:

• CATALYSIS (from the Gr. Kara, down, and Meta, to loosen)

catalysis is treated under CHEMICAL ACTION; in this See also:

• ARTICLE (from Lat. articulus, a joint)

article mention will be made of some of the more interesting examples.501 A See also:

• FAMILIAR (through the Fr. familier, from Lat. familiaris, of or belonging to the familia, family)

familiar instance of a catalytic action is witnessed when a mixture of See also:

• POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium chlorate and See also:

• MANGANESE (symbol Mn; atomic weight, 54.93 (0=16)], a metallic chemical element. Its dioxide (pyrolusite)

manganese dioxide is heated to 35o°, See also:

• OXYGEN (symbol 0, atomic weight 16)

oxygen being steadily liberated, and the manganese dioxide being unchanged at the end of the reaction . The action may be explained as follows:—See also:

• PART

part of the chlorate reacts with the manganese dioxide to form potassium permanganate, See also:

• CHLORINE (symbol Cl, atomic weight 35`46 (0=16)

chlorine and oxygen, the chlorine subsequently reacting with the permanganate to produce manganese dioxide, potassium chloride and oxygen, thus 2KC103+2MnO2 = 2KMnO4+C12+02 = 2KC1+2MnO2-1-302 . This explanation is supported by the facts that traces of chlorine are See also:

• PRESENT

present in the See also:

• GAS

gas, and the See also:

• PINK

pink permanganate can be recognized when little dioxide is used . Other oxides bring about the same decomposition at temperatures below that at which the chlorate yields oxygen when heated alone; but since such substances as See also:

• KAOLIN

kaolin, See also:

• PLATINUM [symbol Pt, atomic weight 145.0 (0=16)]

platinum See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black and some other finely powdered compounds exercise the same effect, it follows that the explanation given above is not quite See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general . Another example is See also:

• DEACON (Gr. S&& ovos, minister, servant)

Deacon's See also:

• PROCESS

process for the manufacture of chlorine by passing hydrochloric See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid gas mixed with See also:

• AIR (from an Indo-European root meaning " breathe," " blow ")
• AIR, or ASBEN

air over heated bricks which had been previously impregnated with a See also:

• COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

copper sulphate See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution . The nitrous gases employed in the See also:

• ORDINARY (med. Lat. ordinarius, Fr. ordinaire)

ordinary chamber process of manufacturing sulphuric acid also See also:

• ACT (Lat. actus, actum)

act catalytically . Mention may be made of the part played by See also:

• WATER

water vapour in conditioning many chemical reactions . Thus See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium will not react with dry chlorine or dry oxygen; See also:

• CARBON (symbol C, atomic weight 12)

carbon, See also:

• SULPHUR

sulphur and See also:

• PHOSPHORUS (Gr. 4ws, light, sPEpety, to bear)

phosphorus will not See also:

• BURN, RICHARD (1709-1785)

burn in perfectly dry oxygen, neither does nitric See also:

• OXIDE

oxide give red fumes of the peroxide . In organic chemistry many catalytic actions are met with .

In the class of reaction known as " condensations," it may be found that the course of the reaction is largely dependent upon the nature of some substance which acts catalytically . One of the most important is the See also:

• FRIEDEL, CHARLES (1832-1899)

Friedel and See also:

• CRAFT (a word common to Teutonic languages for strength, or power; cf. Ger. Kraft)

Craft's reaction, in which an aromatic compound combines with an alkyl haloid in the presence of See also:

• ALUMINIUM (symbol Al; atomic weight 27.0)

aluminium, See also:

• ZINC

zinc or ferric chloride . It seems in this, as in other cases, that addition compounds are first formed which subsequently react with the re-formation of the catalyst . The formation of See also:

• BENZOIN

benzoin from See also:

• BENZALDEHYDE (oil of bitter almonds), C6H5CHO

benzaldehyde in the presence of potassium See also:

• CYANIDE

cyanide is another example; this action has been investigated by G . Bredig and Stern (Zeit . Elektrochem., 1904, 10, p . 582) . The second class of catalytic actions, viz. those occasioned by the presence of a See also:

• METAL
• METAL (through Fr. from Lat. metallum, mine, quarry, adapted from Gr. µATaXAov, in the same sense, probably connected with ,ueraAAdv, to search after, explore, µeTa, after, aAAos, other)

metal or some other substance which under-goes no See also:

• CHANGE (derived through the Fr. from the Late Lat. cambium, cambiare, to barter; the ultimate derivation is probably from the root which appears in the Gr. «a urmu', to bend)

change, is of especial See also:

• INTEREST

interest, and has received much See also:

• ATTENTION (from Lat. ad-tendo, await, expect; the condition of being " stretched " or " tense ")

attention . The accelerating See also:

• INFLUENCE (Late Lat. influentia, from influere, to flow in)

influence of a clean platinum See also:

• PLATE

plate on the See also:

• RATE

rate of See also:

• COMBINATION (Lat. combinare, to combine)

combination of See also:

• HYDROGEN [symbol H, atomic weight x-oo8 (0=16)]

hydrogen and oxygen was studied by See also:

• FARADAY, MICHAEL (1791-1867)

Faraday . He found that with the pure gases the velocity of reaction increased until the mixture exploded . The presence of See also:

• MINUTE
• MINUTE (Lat. minutes, small; minuere, to make less)

minute quantities of carbon monoxide, carbon disulphide, sulphuretted hydrogen and hydrochloric acid inhibited the action; in the See also:

• CASE
• CASE, JOHN (d. 1600)

case of the first two gases, there is no -alteration of the platinum See also:

• SURFACE

surface, since the plate brings about combination when removed to an See also:

• ATMOSPHERE (Gr. fir µ6r, vapour; orkaipa, a sphere)

atmosphere of pure hydrogen and oxygen; with the last two gases, however, the surface is altered, since the plate will not occasion the combination when placed in the pure gases . M .

Bodenstein (Zeit. phys . Chem., 1904, 46, p . 725) showed that combination occurs with measurable velocity at ordinary temperatures in the presence of compact platinum . More energetic combination is observed if the metal be finely divided, as, for instance, by immersing See also:

• ASBESTOS

asbestos See also:

• FIBRES
• FIBRES (or FIBERS, in American spelling; from Lat. fibra, apparently connected either with filum, thread, or findere, to split)

fibres in a solution of platinum chloride and strongly See also:

• HEATING

heating . The " spongy " platinum so formed brings about the combination of See also:

• AMMONIA (NH3)

ammonia and oxygen to form water and nitric acid, of nitric oxide and hydrogen to form ammonia (see See also:

• GERMAN
• GERMAN, DUTCH AND SCANDINAVIAN

German Patent, 1905, 157,287), and of sulphur dioxide and oxygen to form sulphur trioxide . The last reaction, which receives commercial application in the contact process of sulphuric acid manufacture, was studied by M . Bodenstein and W . Pohl (Zeit . Elektrochem., 1905, 11, p . 373), who found that the See also:

• EQUILIBRIUM (from the Lat. aequus, equal, and libra, a balance)

equilibrium followed the See also:

• LAW
• LAW (0. Eng. lagu, M. Eng. lawe; from an old Teutonic root lag, " lie," what lies fixed or evenly; cf. Lat. lex, Fr. loi)
• LAW, JOHN (1671—1729)
• LAW, WILLIAM (1686-1761)

law of See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass-action (see also F . W . Kuster, Zeit. anorg .

Chem., 1904, 42, p . 453, R . See also:

• LUCAS, CHARLES (1713–1771)
• LUCAS, JOHN SEYMOUR (1849– )
• LUCAS, SIR CHARLES (d. 1648)

Lucas, Zit . Elektrochem., 1905, 11, p . 457) . Other metals, such as See also:

• NICKEL
• NICKEL (symbol Ni, atomic weight 58.68 (0=16))

nickel, See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron, &c., can also react as catalysts . The use of finely divided nickel (obtained by reducing the oxide in a current of pure hydrogen at a temperature of 350) has been carefully studied by P . See also:

• SABATIER, LOUIS AUGUSTE (1839-1901)

Sabatier and J . B . Senderens; a See also:

• SUMMARY

summary of their results is given in the See also:

• ANN

Ann . Chim . Phys., 1905 (viii.) 4, pp, 319-488 .

Of See also:

• SPECIAL

special interest is the condensation of See also:

• ACETYLENE

acetylene . If this gas mixed with hydrogen be passed over the reduced nickel in the See also:

• COLD (in O. Eng. cald and ceald, a word coming ultimately from a root cognate with the Lat. gelu, gelidus, and common in the Teutonic languages, which usually have two distinct forms for the substantive and the adjective, cf. Ger. Kolte, kalt, Dutch koude

cold, the temperature may rise to as high as 1500, the acetylene disappearing and becoming replaced by a substance like See also:

• PETROLEUM (Lat. Petra, rock, and oleuin, oil)

petroleum . If the nickel be maintained at 200°, and the gases circulated for twenty-eight See also:

• HOURS, CANONICAL

hours, a product, condensible to a yellow liquid having a beautiful See also:

• FLUORESCENCE

fluorescence and boiling at 450, is obtained . This substance closely resembles ordinary Pennsylvanian petroleum . If acetylene be passed alone over nickel heated to 200°-300 , a mixture, boiling at 60°-70° and having a See also:

• GREEN, A
• GREEN, ALEXANDER HENRY (1832—1896)
• GREEN, DUFF (1791—1875)
• GREEN, JOHN RICHARD (1837—1883)
• GREEN, MATTHEW (1696-1737)
• GREEN, THOMAS HILL (1836-1882)
• GREEN, VALENTINE (1739–1813)
• GREEN, WILLIAM HENRY (.1825–1900)

green See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour by diffused and a red by transmitted See also:

• LIGHT

light, was obtained . This substance closely resembles Caucasian petroleum . The decomposition of carbon monoxide according to the reaction 2CO-4 C+See also:

• CO2

CO2 is purely catalytic in the presence of nickel and See also:

• COBALT (symbol Co, atomic weight 59)

cobalt, and also in the presence of iron, so See also:

• LONG, GEORGE (1800-1879)
• LONG, JOHN DAVIS (1838– )

long as the amount of carbon dioxide present does not exceed a certain amount (R . Schenck and W . See also:

• HELLER, STEPHEN (181 1888)

Heller, Ber., 1905, 38, pp . 2132, 2139) . It is of interest that finely divided aluminium and See also:

• MAGNESIUM [symbol Mg, atomic weight 24.32 (0 = 16)]

magnesium decompose methane, ethane, and See also:

• ETHYLENE, or ETHENE, C2H4

ethylene into carbon and hydrogen in the same way as nickel . See also:

• CHARCOAL

Charcoal at 3500 also reacts catalytically; for example, Senderens found that See also:

• ETHYL

ethyl See also:

• ALCOHOL

alcohol was decomposed by See also:

• ANIMAL
• ANIMAL (Lat. animalis, from anima, breath, soul)

animal charcoal into methane, ethylene, hydrogen, carbon monoxide and a little carbon dioxide, and propyl alcohol gave propylene, ethane, carbon monoxide and hydrogen, while G .

Lemoine obtained from ethyl alcohol and See also:

• WOOD, ANTHONY A2 (1632-1695)
• WOOD, JOHN GEORGE (1827—1889)
• WOOD, MRS HENRY [ELLEN] (1814—1887)
• WOOD, SEARLES VALENTINE (1798—188o)

wood charcoal a mixture of acetaldehyde and hydrogen .