Methyl orange is an acid-base indicator, in acid it turns red and in a base it turns yellow.
Acid-base indicator is a weak acid or weak base, such as litmus, methyl orange or phenolphthalein, which changes colour when it gains or loses an H+ ion.
Adrenaline was the first naturally produced hormone to be isolated in its pure state. It is known as epinephrine, but its chemical name is 1-[3,4-dihydroxyphenol]-2-methylaminoethanol. Adrenaline is a hormone, produced by the medulla of the adrenal glands, that increases heart activity, improves the power and prolongs the action of muscles, and increases the rate and depth of breathing to prepare the body for "fright, flight, or fight". At the same time it inhibits digestion and excretion.
Amines are compounds formally derived from ammonia by replacing one, two, or three hydrogen atoms by hydrocarbyl groups, and having the general structures RNH2 (primary amines), R2NH (secondary amines), R3N (tertiary amines). Examples are methylamine, CH3NH2; dimethylamine, CH3NHCH3; and trimethylamine, (CH3)3N.
Butane is a gaseous hydrocarbon C4H10 obtained from petroleum (refinery gas or by cracking higher hydrocarbons). The fourth member of the alkane series, it has a straight chain of carbon atoms and is isomeric with 2-methylpropane, formerly called isobutene. It can easily be liquefied under pressure and is supplied into cylinders for use as a fuel gas. It is also a raw material for making buta-1, 3-diene for synthetic rubber.
Cetane number is a measure of the ignition quality of diesel fuel. It denotes the volume fraction of cetane (C16H34) in a combustible mixture (containing cetane and 1-methylnapthalene) whose ignition characteristics match those of the diesel fuel being tested. Cetane is a collection of un-branched open chain alkane molecule that ignites very easily under compression, so it was assigned a cetane number of 100, while alpha-methyl naphthalene was assigned a cetane number of 0.
Coal tar is a material obtained from the destructive distillation of coal in the production of coal gas. The crude tar contains a large number of organic compounds (e.g. benzene, naphthalene, methylbenzene, etc.), which can be separated by fractional distillation.
Series of compounds which have a common general formula and in which each member differs from the next member by a constant unit, which is the methylene group (-CH2-) is called the homologous series. Members of a homologous series are called homolog.
An example of the homologous series with some of their homologs are given below. Straight chain alkanes having general formula CnH2n+2
Structure | Name |
---|---|
CH4 | methane |
CH3-CH3 | ethane |
CH3-CH2-CH3 | propane |
CH3-CH2CH2CH3 | butane |
CH3-(CH2)3-CH3 | pentane |
CH3-(CH2)4-CH3 | hexane |
CH3-(CH2)5-CH3 | heptane |
CH3-(CH2)6-CH3 | octane |
CH3-(CH2)7-CH3 | nonane |
CH3-(CH2)8-CH3 | decane |
Mannich reaction is a process in which hydrogen atoms in organic compounds are replaced with a methyl group.
Indicator is a substance used to show the presence of a chemical substance or ion by its colour. Acid-base indicators are compounds, such as phenolphtaleine and methyl orange, which change colour reversibly, depending on whether the solution is acidic or basic. Oxidation-reduction indicators are substances that show a reversible colour change between oxidised and reduced forms.
Generalic, Eni. "Methyl." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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