Answer:
Electronegativity generally increases from left to right across a period,
Explanation:
The true statement from the given choices is that electronegativity generally increases from left to right across a period.
Electronegativity is the measure of the relative tendency with which an atom of the element attract valence electrons in a chemical bond.
Across a period electronegativity increases from left to right and decreases down the group.
This is due to reduction in metallic properties as we move across the period from left to right.
Answer:
1.
Explanation:
Hello,
In this case, for the given reaction we first assign the oxidation state for each species:

Whereas the half reactions are:

Next, we exchange the transferred electrons:

Afterwards, we add them to obtain:

By adding and subtracting common terms we obtain:

Finally, by removing the oxidation states we have:

Therefore, the smallest whole-number coefficient for Sn is 1.
Regards.
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.
So calculate the H for the other two reactions a room temperature and combine the reactions to calculate the H of the decomposition of calcium carbonate using the Hess's Law