Answer:
%Li-6 = 5.996% & %Li-7 = 94.004%
Explanation:
let X₁ = Li-6 & X₂ = Li-7 where Xₙ = mole fraction
X₁ + X₂ = 1 => X₁ = 1 - X₂
6·X₁ + 7·X₂ = 6.94004
=> 6(1 - X₂) + 7·X₂ = 6.94004
=> 6 - 6·X₂ + 7·X₂ = 6.94004
=> 6 + X₂ = 6.94004
X₂ = 6.94004 - 6 = 0.94004 => %X₂ = %Li-7 = 94.004%
X₁ = 1.00000 - 0.94004 = 0.05996 => %X₁ = %Li-6 = 5.996%
Answer:
a. electrophilic aromatic substitution
b. nucleophilic aromatic substitution
c. nucleophilic aromatic substitution
d. electrophilic aromatic substitution
e. nucleophilic aromatic substitution
f. electrophilic aromatic substitution
Explanation:
Electrophilic aromatic substitution is a type of chemical reaction where a hydrogen atom or a functional group that is attached to the aromatic ring is replaced by an electrophile. Electrophilic aromatic substitutions can be classified into five classes: 1-Halogenation: is the replacement of one or more hydrogen (H) atoms in an organic compound by a halogen such as, for example, bromine (bromination), chlorine (chlorination), etc; 2- Nitration: the replacement of H with a nitrate group (NO2); 3-Sulfonation: the replacement of H with a bisulfite (SO3H); 4-Friedel-CraftsAlkylation: the replacement of H with an alkyl group (R), and 5-Friedel-Crafts Acylation: the replacement of H with an acyl group (RCO). For example, the Benzene undergoes electrophilic substitution to produce a wide range of chemical compounds (chlorobenzene, nitrobenzene, benzene sulfonic acid, etc).
A nucleophilic aromatic substitution is a type of chemical reaction where an electron-rich nucleophile displaces a leaving group (for example, a halide on the aromatic ring). There are six types of nucleophilic substitution mechanisms: 1-the SNAr (addition-elimination) mechanism, whose name is due to the Hughes-Ingold symbol ''SN' and a unimolecular mechanism; 2-the SN1 reaction that produces diazonium salts 3-the benzyne mechanism that produce highly reactive species (including benzyne) derived from the aromatic ring by the replacement of two substituents; 4-the free radical SRN1 mechanism where a substituent on the aromatic ring is displaced by a nucleophile with the formation of intermediary free radical species; 5-the ANRORC (Addition of the Nucleophile, Ring Opening, and Ring Closure) mechanism, involved in reactions of metal amide nucleophiles and substituted pyrimidines; and 6-the Vicarious nucleophilic substitution, where a nucleophile displaces an H atom on the aromatic ring but without leaving groups (such as, for example, halogen substituents).
Answer:
Explanation:
mass of one virus = 9.0 x 10⁻¹² mg
mass of one mole = 6.02 x 10²³ x mass of one virus
= 6.02 x 10²³ x 9.0 x 10⁻¹²
= 54.18 x 10¹¹ mg
= 54 x 10⁸ g .
= 54 x 10⁵ kg .
b )
let n be no of moles of virus that will be equal to weight of oil tanker
n x 54 x 10⁵ = 3 x 10⁷
n = 5.5555
rounding off to 2 significant figure
5.6 moles Ans .
Answer:
defined as a process in which mo heat transfer take place
Explanation:
is a process which occurs without transferring heat /mass between the system and it's surrounding.
Ecologists use food web diagrams as tools in their studies of different populations of organisms within an ecosystem because it shows the feeding relationship between organisms in the ecosystem.
<h3>What is a Food web?</h3>
This is defined as the graphical representation of the feeding relationship which occurs between organisms in the ecosystem and helps to predict the outcome in the addition or removal of a species.
The food web also helps to determine the various ways in which energy flows and it usually starts from the producers which are the plants as a result of their photosynthetic ability which involves the conversion of solar energy to chemical energy.
There are various organisms in the ecosystem and the food web helps to provide a better understanding of their feeding habits and impact various factors will result in.
Read more about Food web here brainly.com/question/4656320
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