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순도시험
이 품목의 채취량은 온도 20℃, 압력 760mmHg에서의 용량으로 환산하여야 한다.
(1) 유리산 : 이 품목 1,000mL를 새로 끓여서 식힌 물 50mL에 통과시킨다. 이 때 이 품목 1,000mL를 15분간에 통과하도록 속도를 조절하고 도관은 지름 약 1mm의 것을 쓰고 물은 12～14cm의 높이가 되도록 50mL의 메스실린더를 쓰며 도관의 끝이 바닥으로부터 2mm의 높이에 오르도록 한다. 이 품목을 통과시킨 다음에 이 물을 같은 길이의 두개의 비색관중 하나에 넣고 다른 하나의 비색관에는 새로 끓여서 식힌 물 50mL와 0.01N 염산 1mL를 넣고 양비색관에 각각 메틸오렌지시액 0.1mL를 가하여 섞고 양 관의 색을 투시하여 비교할 때, 검체를 넣은 관의 색이 0.01N 염산을 가한 관의 색보다 진해서는 아니 된다.
(2) 인화수소, 황화수소 및 환원성유기물 : 이 품목 1,000mL를 질산은암모니아시액 25mL와 암모니아시액 3mL의 혼액에 통하였을 때, 이 품목을 통하지 아니한 같은 액보다 혼탁 또는 어두운 액이 나타나서는 아니 된다.
(3) 일산화탄소 : 일산화탄소검지관의 양단을 절단하여 그 일단을 이 품목의 용기와 연결하고 다른 끝을 적당한 유량계에 연결한다. 이 품목 약 300mL를 매분 약 100mL의 속도로 통과시켰을 때, 검지관의 황색부분이 대조 검지관에 공기를 300mL 통과시킨 것보다 진한 녹색이 나타나서는 아니 된다(10ppm 이하).
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확인시험
이 품목은 불을 꺼지게 하고 수산화칼슘시액에 통하면 백색침전이 생기며 이 침전은 초산(1→4)을 가하면 거품을 내면서 녹는다.
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정량법
검체채취는 순도시험에 따른다. 적당한 용량의 가스피펫에 수산화나트륨용액(1→3)을 넣어준다. 이어서 이 품목 100mL 이상을 미리 염화나트륨용액(3→10)을 채워둔 100mL 이상의 가스피펫 중에 정확하게 취한 다음 이것을 가스피펫에 옮기고 잘 흔들어 섞어준다. 다음에 흡수되지 않고 남아있는 가스의 용량이 항량이 되었을 때, 그 용량을 측정하여 V(mL)로 하고 다음 계산식에 따라 함량을 구한다.
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개요
Carbon dioxide is a colorless, odorless, noncombustible gas present throughout the atmosphere and is an essential compound for life on Earth. It is found on other planets in the solar system. Mars’s icecaps are primarily frozen carbon dioxide and Venus’s atmosphere is mostly carbon dioxide. Carbon dioxide occurs naturally as approximately 0.03% v/v of the atmosphere.Solid carbon dioxide, also known as dry ice, is usually encountered as white-colored pellets or blocks.
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화학적 성질
Carbon dioxide,CO2, also known as carbonic anhydride and carbonic acid gas, is a colorless,odorless gas that liquifies at -65 °C(-86 OF) and solidifies in dry ice at -78.2 °C(-107 OF). It is soluble in water,alcohol, and most alkaline solutions. In a relatively slow reaction,carbon dioxide hydrates in water to become carbonic acid and is corrosive. In petroleum production, the velocity of the carbon dioxide gas can increase the corrosion rate to very high levels,with the presence of salts becoming unimportant. Carbon dioxide is used in preparing carbonated beverages, fire extinguishers, dry ice refrigerants,and as a raw material in the production of sodium carbonate and sodium bicarbonate using the Solvay procedure.
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물리적 성질
Colorless, odorless and tasteless gas; 1.53 times heavier than air; density 1.80 g/L at 25°C; can be liquefied under pressure; liquefies at -56.6°C at 5.2 atm; density of liquid CO2 at 0°C and 34 atm 0.914 g/mL; solidifies to white snow-like flakes known as dry ice, density 1.56 g/cm3 at -79°C; dry ice sub limes to CO2 gas at -78.5°C; critical temperature 31°C; critical pressure 72.79 atm, critical density 94 cm3/mol; moderately soluble in water, solubility 173 mL and 88mL CO2/100 mL water at 0°C and 20°C, respectively; solubility increases with pressure.
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역사
The discovery of carbon dioxide, credited to Joseph Black (1728–1799), played a critical role in supplanting the phlogiston theory and advancing the development of modern chemistry. Black, in his medical studies, was searching for a substance to dissolve kidney stones, but he switched his subject to a study of stomach acidity. Black was working with the carbonates magnesia alba (magnesium carbonate) and calcium carbonate (limestone) and observed that when magnesia alba was heated or reacted with acids, it produced a gas and a salt. Black, who published his work in 1756, called the gas “fixed air” and noted that it had properties similar to those described by Jan Baptista van Helmont (1577–1644) for spiritus sylvestrius. Spiritus sylvestrius was the gas produced during combustion processes, and van Helmont realized that this was the same gas produced during fermentation and when acids reacted with seashells.
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용도
Carbon Dioxide is a gas obtained during fermentation of glucose
(grain sugar) to ethyl alcohol. it is used in pressure-packed foods as
a propellant or aerating agent and is also used in the carbonation of
beverages. it is released as a result of the acid carbonate reaction of
leavening agents in baked goods to produce an increase in volume.
as a solid, it is termed dry ice and is used for freezing and chilling.
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생산 방법
Carbon dioxide is obtained industrially in large quantities as a byproduct
in the manufacture of lime; by the incineration of coke or
other carbonaceous material; and by the fermentation of glucose by
yeast. In the laboratory it may be prepared by dropping acid on a
carbonate.
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정의
1. The
solution of carbon dioxide in a liquid
under pressure, as in carbonated soft
drinks.
2. The addition of carbon dioxide to compounds,
e.g. the insertion of carbon dioxide
into Grignard reagents.
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제조 방법
Carbon dioxide is produced as a by-product in many processes. It is pro duced as a by-product in the manufacture of lime from calcium carbonate:
CaCO3 →CaO + CO2
CO2 also is derived from synthesis gas which is a mixture of CO, CO2, H2 and N2 from air obtained by steam reforming. Carbon dioxide also is obtained by combustion of natural gas:
CH4 + 2O2 → CO2 + 2H2O
It also is obtained as a by-product in the Haber-Bosch process for the man ufacture of ammonia. The method involves passing steam and air over hot coke.
Carbon dioxide also is produced along with ethanol from fermentation of carbohydrates by yeast:
C6H12O6→2CO2 + 2C2H5OH
In the laboratory, CO2 may be produced by the reaction of any carbonate with a dilute mineral acid:
CaCO3 + 2HCl → CaCl2 + CO2 + H2O
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일반 설명
An odorless, white solid. Can cause damaging frostbite. Noncombustible and nontoxic. Liquefies at -109°F. Can asphyxiate by displacement of air. Used as a refrigerant.
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공기와 물의 반응
Water soluble. Forms carbonic acid, a mild acid in water.
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반응 프로필
Contact of very cold liquid/solid carbon dioxide with water may result in vigorous or violent boiling of the product and extremely rapid vaporization due to the large temperature differences involved. If the water is hot, there is the possibility that a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if liquid gas contacts water in a closed container. With water forms weak carbonic acid in nonhazardous reaction. Dusts of magnesium, lithium, potassium, sodium, zirconium, titanium, and some magnesium-aluminum alloys, and heated aluminum, chromium, and magnesium when suspended in carbon dioxide are ignitable and explosive. This is especially true in the presence of strong oxidizers, such as peroxides. The presence of carbon dioxide in solutions of aluminum hydride in ether can cause violent decomposition on warming the residue, [J. Amer. Chem. Soc., 1948, 70, 877]. Dangers arising from the use of carbon dioxide in the fire prevention and extinguishing systems of confined volumes of air and flammable vapors are examined. The hazard associated with its use centers around the fact that large electrostatic discharges may be created that initiate explosion, [Quart. Saf. Summ., 1973, 44(1740, 10].
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위험도
Solid damaging to skin and tissue; keep
away from mouth and eyes. Asphyxia.
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건강위험
Carbon dioxide is an asphyxiant. Exposureto about 9–10% concentration can causeunconsciousness in 5 minutes. Inhalation of3% CO2 can produce weak narcotic effects.Exposure to 2% concentration for severalhours can produce headache, increased bloodpressure, and deep respiration. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
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화재위험
Non-flammable gases. Containers may explode when heated. Ruptured cylinders may rocket.
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농업용
Solid carbon dioxide is known as dry ice. It is produced by cooling gaseous carbon dioxide under pressure.
Dry ice is used in refrigeration, carbonated drinks and fire extinguishers. It is also a constituent of medical gases, as it promotes exhalation.
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Safety Profile
An asphpant. See
discussion of simple asphyxiants under
ARGON. Experimental teratogenic and
reproductive effects. Contact of solid
carbon dioxide snow with the skin can cause
burns. Dusts of magnesium, zirconium,
titanium, and some magnesium-aluminum
alloys igmte and then explode in COa
atmospheres. Dusts of aluminum,
chromium, and manganese ignite and then
explode when heated in CO2. Several bulk
metals wlll burn in CO2. Reacts vigorously with (Al + Na2O2), Cs2O, Mg(C2H5)2, Li,
(Mg + Na2O2), K, KHC, Na, Na2C2, NaK,
Ti. CO2 fire extingushers can produce
highly incendiary sparks of 5-1 5 mJ at
10-20 kV by electrostatic discharge.
Incompatible with acrylaldehyde, aziridme,
metal acetylides, sodium peroxide.
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Safety
In formulations, carbon dioxide is generally regarded as an
essentially nontoxic material.
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잠재적 노출
Gaseous Carbon dioxide is used to
carbonate beverages; as a weak acid in the textile, leather,
and chemical industries; in water treatment; and in the
manufacture of aspirin and white lead; for hardening molds
in foundries; in food preservation, in purging tanks and
pipe lines; as a fire extinguisher, in foams; and in welding.
Because it is relatively inert, it is utilized as a pressure
medium. It is also used as a propellant in aerosols; to promote plant growth in green houses; it is used medically as
a respiratory stimulant; in the manufacture of carbonates;
and to produce an inert atmosphere when an explosive or
flammable hazard exists. The liquid is used in fire extinguishing equipment; in cylinders for inflating life rafts; in
the manufacturing of dry ice, and as a refrigerant. Dry ice
is used primarily as a refrigerant. Occupational exposure to
carbon dioxide may also occur in any place where fermentation processes may deplete oxygen with the formation of
carbon dioxide, e.g., in mines, silos, wells, vats, ships’
holds, etc.
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환경귀착
Carbon dioxide is an asphyxiant, means it causes toxicity by
displacing oxygen from the breathing atmosphere primarily in
enclosed spaces or in open spaces due to sudden release of
massive amounts of CO2 (for example, forests fire or natural
emission during a volcanic eruption) and results in hypoxia.
Thehumanbody produces about 12 000–13 000 mmols per day
of CO2 and is excreted primarily via lungs. The CO2 concentration
in plasma is maintained within a narrow range of
40±5 mm Hg (4.7–6 KPa). At plasma concentration of
22.5mmHg (3 KPa) or less death can occur within few minutes.
The cause of death in breathing high concentration ofCO2 is due
to CO2 poisoning, that results in rapid decrease in blood pH
(respiratory acidosis,
Low concentrations of CO2 in the air, or insufficient time for
CO2 in blood to exchange with oxygen (O2) in air such as in the
situations of hyperventilation, can lead to an increase in blood
pH (respiratory alkalosis, >pH 7.45). The reaction of CO2 with
water in the body is catalyzed by the enzyme carbonic anhydrases
(or carbonate dehydratases), which leads to formation of carbonic
acid, followed by dissociation into protons (H+) and bicarbonate
(HCO3-
). Carbonic acid is buffered in the cell primarily
by hemoglobin and proteins, which have limited capacity.
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저장
Extremely stable and chemically nonreactive. Store in a tightly
sealed cylinder. Avoid exposure to excessive heat.
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운송 방법
Carbon dioxide (UN1013, UN2187), Hazard
Class: 2.2; Labels: 2.2-Nonflammable compressed gas. Dry
ice (UN1845), Hazard class 9 is considered a “miscellaneous hazardous material” and does not require a label.
The gas and refrigerated liquid fall in Hazard Class 2.2 and
there is no Packing Group; solid, dry ice falls in Hazard
Class 9. Solid, dry ice carries the symbol “AW.” The letter
“A” restricts the application of requirements of this subchapter to materials offered or intended for transportation
by aircraft, unless the material is a hazardous substance or
a hazardous waste. The letter “W” restricts the application
of requirements of this subchapter to materials offered or
intended for transportation by vessel, unless the material is
a hazardous substance or a hazardous waste. Cylindersmust be transported in a secure upright position, in a wellventilated truck. Protect cylinder and labels from physical
damage. The owner of the compressed gas cylinder is the
only entity allowed by federal law (49CFR) to transport
and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express
written permission of the owner.
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Purification Methods
Pass the gas over CuO wire at 800o to oxidise CO and other reducing impurities (such as H2), then over copper dispersed on Kieselguhr at 180o to remove oxygen. Drying it at -78o removes the water vapour. Final purification is by vacuum distillation at liquid nitrogen temperature to remove non-condensable gases [Anderson et al. J Chem Soc 3498 1962]. Sulfur dioxide contaminant can be removed at 450o using silver wool combined with a plug of platinised quartz wool. Halogens are removed by using Mg, Zn or Cu, heated to 450o. [Glemsner in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 647 1963.]
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폐기물 처리
Return refillable compressed
gas cylinders to supplier. Vent to atmosphere
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Regulatory Status
GRAS listed. Accepted for use in Europe as a food additive.
Included in the FDA Inactive Ingredients Database (aerosol
formulation for nasal preparations; IM and IV injections). Included
in the Canadian List of Acceptable Non-medicinal Ingredients.
