Her words seemed to make him happy and (to) pacify his inner turmoil.
Is the sentence correct both with or without the second "to" in bold?
Her words seemed to make him happy and pacify his inner turmoil.
Her words seemed to make him happy and to pacify his inner turmoil.
Both are correct, and the meaning is much the same. The second form, with the extra "to" is perhaps a bit more formal, some people might even find it slightly pedantic. The shorter form is now more common. The longer form slightly emphasizes a separation between "to make him happy" and "to pacify his inner turmoil" while the shorter form more treats thEM as a single joint effect. But that is a subtle difference.
No, because the word "and" is acting as a connector. Both the verbs, happy and pacify, are a part of the prepositional phrase and refers to "to"
Her words seemed to make him happy and pacify his inner turmoil.