Answer:
The order of reactivity towards electrophilic susbtitution is shown below:
a. anisole > ethylbenzene>benzene>chlorobenzene>nitrobenzene
b. p-cresol>p-xylene>toluene>benzene
c.Phenol>propylbenzene>benzene>benzoic acid
d.p-chloromethylbenzene>p-methylnitrobenzene> 2-chloro-1-methyl-4-nitrobenzene> 1-methyl-2,4-dinitrobenzene
Explanation:
Electron donating groups favor the electrophilic substitution reactions at ortho and para positions of the benzene ring.
For example: -OH, -OCH3, -NH2, Alkyl groups favor electrophilic aromatic substitution in benzene.
The -I (negative inductive effect) groups, electron-withdrawing groups deactivate the benzene ring towards electrophilic aromatic substitution.
Examples: -NO2, -SO3H, halide groups, Carboxylic acid groups, carbonyl gropus.
Answer:
the advantages of modern periodic tables are given below and explained.
- position of hydrogen:since hydrogen has the least atomic number i.e 1 ,it is kept in group 1 of modern periodic table, but still controversial due to its. dual characteristics since it shows the characteristics of borh group 1 and group 17.
- position of isotopes :isotopes are element having the same atomic number but different atomic weight . Without any doubt all isotopes of one element and kept in one place.
- position of lanthanide and acnitinides: element of Lanthanides series and element of Actinides series are kept below the main block of the periodic table as they have different properties from other elements.
- correction of periodic law: some elements do not obey mendeleev periodic law , but when they are arranged according to atomic number they obey the modern periodic law.
- position of alkali metals and coinage metals : in modern periodic table , alkali metal are kept in group IA and coinage metals are in group.
hope this helped you☺️
any confusion then comment it and let me know.
actually as I say these points say that the modern periodic table is better than mendeleev periodic table so, don't get confused.
Answer:
The heat that was used to melt the 15.0 grams of ice at 0°C is 4,950 Joules
Explanation:
The mass of ice in the beaker = 15.0 grams
The initial temperature of the ice = 0°C
The final temperature of the ice = 0°C
The latent heat of fusion of ice = 330 J/g
The heat required to melt a given mass of ice = The mass of the ice to be melted × The latent heat of fusion of ice
Therefore, the heat, Q, required to melt 15.0 g of ice = 15.0 g × 330 J/g = 4,950 J
The heat that was used to melt the 15.0 grams of ice = 4,950 Joules.
The answer for this issue is:
The chemical equation is: HBz + H2O <- - > H3O+ + Bz-
Ka = 6.4X10^-5 = [H3O+][Bz-]/[HBz]
Let x = [H3O+] = [Bz-], and [HBz] = 0.5 - x.
Accept that x is little contrasted with 0.5 M. At that point,
Ka = 6.4X10^-5 = x^2/0.5
x = [H3O+] = 5.6X10^-3 M
pH = 2.25
(x is without a doubt little contrasted with 0.5, so the presumption above was OK to make)
