Complete the mechanism for the reaction by adding the missing curved arrows, atoms, bonds, charges, and nonbonding electron pairs. note the resonance arrows) in the scheme.

See explanation below

Explanation:

In picture 1 attached, we have the starting structure. In picture 2, you have the answer for this.

Basically this is an acid base reaction to promove then, a condensation of the molecule.

In the first step, the carbonile substract a H atom from the HCl. Then, by resonance the OH+, pass the charge to the carbon, which is tertiary and can be easily stabilized. Now, after this, the Chlorine substract an Hydrogen to get a double bond on the carbon with the charge, and this be stable. Now, a second molecule of benzaldehyde reacts with this, so we can have a condensation product.

See picture 2 for complete mechanism.

fe 55.85 g/mol and h2o 18.02 g/mol.