Alkanes Flashcards
What are saturated compounds?
Saturated compounds are compounds that contain atoms that are joined only by single covalent bonds.
What are Unsaturated compounds?
Unsaturated compounds are compounds that contains carbon atoms joined by double/triple covalent bonds.
Alkane are also know as
Paraphenes
The general molecular formula of alkanes is
CnH2n+2
What does the name paraphene imply?
Paraphene means little affinity and are relatively unreactive in comparison with their unsaturated counterpart.
Amongst platinum, palladium and Nickel catalyst which is least reactive
Nickel catalyst
What is the condition for reduction of haloalkanes in the synthetic preparation of alkane?
Zinc copper couple(Zn-Cu) in aqueous alcohol
How is alkane produced from Grignard Reagent(RMgX- Alkyl-Magnesium halide)
It is treated with aqueous hydrochloric or sulphur ic acid.
In Wurtz synthesis alkane is prepared by…
Addition of metallic sodium(Na) and haloalkane(Rx) in dry ether.(C²H⁵)
It gives an alkane and sodium halide.
An example in dry ether is..
Ethoxyethane
C²H⁵
What are the synthetic methods of preparing methane?
- Decarboxylation of Sodium Ethanoate(Acetate)- CH³COONA
- Treatment of aluminium carbide with hot water or dilute acid.
Alkanes undergo halogenation in the presence of………. at a temperature of………… yielding a mixture of…
Ultra-Violet rays
250°c- 400°c
Alkyl Halide
What is the condition in the treatment of Aluminium Carbide to give methane and Aluminium chlorine
Hot water
Dichloromethane, Trichloromethane and Tetrachloromethane are known as..
Methylenechloride
Chloroform
CarbonTetrachloride
Does halogenation of alkanes the place in light…
Halogenation of alkanes does not occur in the dark.
Nitroalkanes are useful
Commercial solvents.
In the Nitration of alkanes using Nitric acid what is the temperature condition and the mechanism, and product also….
150°c to 400°c
A free radical mechanism
Nitro-alkane
C¹ to C⁴ are…
C⁵ to C¹⁷ are…
The remaining are…..
Gases
Liquids
Solids at 20°c
What is the solubility of Alkanes?
Solubility. Alkanes (both alkanes and cycloalkanes) arevirtually insoluble in water, but dissolve in organic solvents such as benzene, Ethoxyethane.
Explain the density of Alkane?
Alkanes are less dense than water, they have densities in the range of 0.6 to 0.8g/cm³.
The density of alkanes increases with increasing….
Molecular weight
The boiling points and melting points of alkanes increases with..
Increasing number of carbon atoms
Branching decreases the ……
Boiling point of alkanes thereby increasing volatility. Thus a branched alkane boils at a lower temperature than the straight chain with the same number of carbon atoms
What causes branched alkanes to boil at lower temperature
This is due to decreased surface area in branched alkanes and consequently decreased vanderwaals forces which the requires a low-temperature.
