What is selectivity in halogenation?
Radical halogenation is selective for the most substituted C-H. More Substituted Radicals Are More. Stable (by Hyperconjugation)
Which halogen have more selectivity for alkane?
Bromination of alkanes occurs by a similar mechanism, but is slower and more selective because a bromine atom is a less reactive hydrogen abstraction agent than a chlorine atom, as reflected by the higher bond energy of H-Cl than H-Br.
Which element is most selective in its halogenation?
The fluorine radical is the most reactive of the halogen radicals, and it reacts violently with alkanes.
Which version of the radical halogenation of an alkane is most selective?
Bromination
Bromination is selective for the R-H that gives the most stable radical. Chlorination is less selective.
What is reactivity and selectivity principle in alkane?
In chemistry the reactivity–selectivity principle or RSP states that a more reactive chemical compound or reactive intermediate is less selective in chemical reactions.
Why is br2 more selective?
Why is Br2 more selective than Cl2?
Which halogen reacts most readily with alkanes?
Fluorine (F2), the lightest halogen, combines explosively with most hydrocarbons.
What do you mean by reactivity and selectivity?
In chemistry the reactivity–selectivity principle or RSP states that a more reactive chemical compound or reactive intermediate is less selective in chemical reactions. In this context selectivity represents the ratio of reaction rates.
What is the difference between reactivity and selectivity?
Why bromine is more selective than chlorine in halogenation reaction of alkanes?
Which of the following is most reactive towards hydrogen a Cl2 B F2 C Br2 D I2?
As a result, the correct sequence of halogen reactivity towards hydrogen is F2>Cl2>Br2>I2.
Which one is more selective chlorination or bromination?
Reason: Bromination of alkane is highly selective compared to chlorination reaction.
Why is bromination highly selective?
The Transition State For Bromination Resembles The Products (A “Late” Transition State) Which Are Farther Apart In Energy. So Selectivity Is High.
Why is Br2 more selective?
What is the reactivity order of halogens towards substitution in alkanes?
The reactivity order of halogenation of alkanes is F2>Cl2>Br2>I2 .
What is the selectivity ratio of chlorine?
This gives us a ratio of 55:15 , or 3.66. So for this reaction, the free radical chlorination of propane at 25°C, chlorine is 3.66 times more selective for secondary hydrogens than for primary hydrogens.
Is chlorination or bromination more selective?
The Transition State For Chlorination Resembles The Reactants (An “Early” Transition State) Which Are Close Together In Energy. So Selectivity Is Low. The Transition State For Bromination Resembles The Products (A “Late” Transition State) Which Are Farther Apart In Energy. So Selectivity Is High.
Which is the most reactive halogen Cl2 Br2 I2 F2?
F2
Order of reactivity towards halogenation is F2 > Cl2 > Br2 > I2 .
How does selectivity affect the reactivity of an alkane?
According to this, the lower the selectivity of a reagent is, the more reactive it is as well. However, chlorination may be a relevant reaction, when the alkane contains only one type of C-H bond, such as in cyclohexane (only secondary). In such cases, the selectivity is irrelevant.
What is halogenation of alkanes?
In the periodic table, Halogens form the 17th group, and they comprise compounds such as chlorine, fluorine, bromine, astatine, and iodine. The substance resulting from a halogenation reaction of alkanes is referred to as a halogenated compound. 2. Can halogenation of alkanes be given as a rearrangement reaction?
Which halogen radical is most reactive with alkane?
The data above indicate that the halogen radicals have different reactivity, fluorine is most reactive and iodine is least reactive. The iodine radical is very unreactive with overall “+” enthalpy, so iodine does not react with alkane at all.
Is chlorination of an alkane a relevant reaction?
However, chlorination may be a relevant reaction, when the alkane contains only one type of C-H bond, such as in cyclohexane (only secondary). In such cases, the selectivity is irrelevant.