Concentrated sulfuric acid (H2SO4) is used to generate the nitronium ion (NO2+) from nitric acid (HNO3) in the nitration of benzene.

The major product is para-nitrotoluene due to steric hindrance at the ortho position, making the para position more favorable for substitution.

The para position is favored in the nitration of toluene due to the electron-donating effect of the methyl group, which stabilizes the carbocation intermediate.

The para position is most likely to be substituted in the nitration of toluene due to the electron-donating effect of the methyl group.

The para position is predominantly substituted due to steric hindrance at the ortho position, making the para product more favorable.

The para-nitrotoluene is formed predominantly due to steric hindrance at the ortho position.

The predominant product is nitrotoluene, specifically ortho- and para-nitrotoluene due to the activating effect of the methyl group.

Aniline will undergo substitution the fastest due to the strong activating effect of the amino group, which donates electron density to the ring.

The position of the third substituent depends on the nature of the existing substituents; however, ortho and para positions are generally favored for activating groups.

The product is benzene sulfonic acid, formed by the electrophilic substitution of sulfur trioxide on benzene.

Decreasing the concentration of SO3 will shift the equilibrium to the right to produce more SO3, according to Le Chatelier's Principle.

Increasing the concentration of O2 will shift the equilibrium to the right, favoring the production of SO3.

Adding SO3 will shift the equilibrium to the left to favor the formation of reactants, according to Le Chatelier's Principle.

Increasing the pressure will shift the equilibrium to the right, favoring the formation of SO3, as it has fewer moles of gas (2 moles) compared to the reactants (3 moles).

Increasing the volume decreases the pressure, and the equilibrium will shift to the side with more moles of gas to counteract the change.

Removing A will shift the equilibrium to the left to produce more A, according to Le Chatelier's Principle.

Increasing pressure will shift the equilibrium to the right, favoring the side with fewer moles of gas.

Adding more CO increases its concentration, which shifts the equilibrium to the right to produce more CH3OH.

Increasing the pressure favors the side with fewer moles of gas. In this case, the right side has fewer moles (1 mole of CH3OH) compared to the left (3 moles), so the equilibrium shifts to the right.

If the reaction is exothermic, decreasing the temperature will shift the equilibrium to the right to produce more products (CH3OH).

Increasing the concentration of HI will shift the equilibrium to the left to reduce the concentration of HI, according to Le Chatelier's Principle.

According to Le Chatelier's principle, increasing the concentration of a product (NH3) will shift the equilibrium to the left, decreasing N2.

Decreasing the concentration of NH3 will shift the equilibrium to the right to produce more NH3, according to Le Chatelier's Principle.

The reaction proceeds via an E2 mechanism due to the strong base (KOH) and the presence of a good leaving group (Br).

The addition of HBr to an alkene follows Markovnikov's rule, leading to the formation of the more stable alkyl bromide as the major product.

According to Markovnikov's rule, the hydrogen from HBr adds to the less substituted carbon of the alkene, leading to the formation of the Markovnikov product.

This reaction is an electrophilic aromatic substitution where bromine acts as an electrophile.

Benzyl chloride can stabilize a carbocation, thus the SN1 mechanism is favored when reacting with a strong nucleophile.

The reaction of benzyl chloride with sodium hydroxide primarily follows the SN1 mechanism due to the stability of the benzyl carbocation formed during the reaction.

The hydrogenation of cyclohexene in the presence of a catalyst leads to the formation of cyclohexane.