Question

Complete the equation for the reaction between each Lewis acid-base pair. In each equation, label which starting material is the Lewis acid and which is the Lewis base; use curved arrows to show the flow of electrons in each reaction. In doing this problem, it is essential that you show valence electrons for all atoms participating in each reaction. a. b. c. d.

Short answer

Question: Complete the equation for the reaction between each Lewis acid-base pair, label which starting material is the Lewis acid and which is the Lewis base, and show the flow of electrons in each reaction using curved arrows. Answer: a. NH3 (Lewis base) + BF3 (Lewis acid) -> N →··· BF3 (curved arrow) b. Cl- (Lewis base) + AlCl3 (Lewis acid) -> Cl-→··AlCl3 (curved arrow) c. OH- (Lewis base) + H+ (Lewis acid) -> OH-→··H+ (curved arrow) d. H2O (Lewis base) + CO2 (Lewis acid) -> H2O →··CO2 (curved arrow)

Step-by-step solution

a. BF3 + NH3 reaction and electron flow

1. Identify the Lewis acid and base: In this reaction, BF3 is the Lewis acid and NH3 is the Lewis base. 2. Show the valence electrons: For the Lewis base, NH3, show the lone pair of electrons on the nitrogen atom. For the Lewis acid, BF3, show three electrons on the boron atom. 3. Use curved arrows to show the flow of electrons: Draw a curved arrow from the nitrogen's lone pair to the boron atom in BF3. The completed equation will be: NH3 (Lewis base) + BF3 (Lewis acid) -> N →··· BF3 (curved arrow)

b. AlCl3 + Cl- reaction and electron flow

1. Identify the Lewis acid and base: In this reaction, AlCl3 is the Lewis acid and Cl- is the Lewis base. 2. Show the valence electrons: For the Lewis base, Cl-, show the eight valence electrons. For the Lewis acid, AlCl3, show six electrons around the aluminum atom. 3. Use curved arrows to show the flow of electrons: Draw a curved arrow from one of the lone pairs of the Cl- to the aluminum atom in AlCl3. The completed equation will be: Cl- (Lewis base) + AlCl3 (Lewis acid) -> Cl-→··AlCl3 (curved arrow)

c. H+ + OH- reaction and electron flow

1. Identify the Lewis acid and base: In this reaction, H+ is the Lewis acid and OH- is the Lewis base. 2. Show the valence electrons: For the Lewis base, OH-, show six valence electrons around the oxygen atom. On the hydrogen ion, there are no electrons. 3. Use curved arrows to show the flow of electrons: Draw a curved arrow from one of the lone pair of electrons on oxygen to the hydrogen ion. The completed equation will be: OH- (Lewis base) + H+ (Lewis acid) -> OH-→··H+ (curved arrow)

d. CO2 + H2O reaction and electron flow

1. Identify the Lewis acid and base: In this reaction, CO2 is the Lewis acid and H2O is the Lewis base. 2. Show the valence electrons: For the Lewis base, H2O, show lone pairs of electrons around the oxygen atom. For the Lewis acid, CO2, show two sets of double-bonded electrons between each carbon and oxygen atom. 3. Use curved arrows to show the flow of electrons: Draw a curved arrow from one of the lone pairs of electrons on the oxygen atom in H2O to the carbon atom in CO2. The completed equation will be: H2O (Lewis base) + CO2 (Lewis acid) -> H2O →··CO2 (curved arrow)