When Jehovah freed his people from slavery in Egypt via Moses which were the Egyptian gods judged? Does each of the 10 plagues correspond to a specific Egyptian god?
NWT Exodus 12:12 " . . . I will execute judgment on all the gods of Egypt. I am Jehovah."
Yes, the plagues sent by God upon the Egyptians were aimed at many of their gods. The purpose was to show how impotent the gods of Egypt were and to force the Pharaoh to let God’s people go.
Exodus 7:14-24 describes how the river Nile was changed into blood, also affecting the streams, canals, ponds and all the reservoirs. The fish died and the water was undrinkable. This, the first plague, was directed at Apis, the god of the Nile, Isis, the goddess of the Nile, and Khnum, guardian of the Nile. The Egyptians believed the Nile was the bloodstream of Osiris, who was reborn each year when the river flooded.
The second plague was delivered seven days later, and is described in Exodus 8:1-15. The plague of frogs (which came from the Nile), was a judgment against Heqet, the frog-headed goddess of birth. Frogs were thought to be sacred. After the frogs died, their stinking bodies were heaped up in offensive piles all through the land (Exodus 8:13–14).
The third plague of gnats was a judgment on Set, the god of the desert. Unlike the previous plagues, the Egyptian magicians were unable to duplicate this one and said to Pharaoh, “This is the finger of God” (Exodus 8:19).
Exodus 8:20-32 describes how the fourth plague, swarms of flies, afflicted only the Egyptians. God’s people, who lived in Goshen, were excluded. This was a judgment on Uatchit, the fly god.
The fifth plague, the death of livestock, was a judgment on the goddess Hathor and the god Apis, who were both depicted as cattle. Exodus 9:1-7 describes how God’s people were unaffected.
The sixth plague, boils, as described in Exodus 9:8-12, was a judgment against Sekhmet, Sunu, and Isis who were ascribed with powers to prevent disease.
There followed a spectacular and dramatic seventh plague, of thunder, hail and lightning. This plague was directed against Nut, the sky goddess, Osiris, the crop fertility god, and Set, the storm god. Exodus 9:13-35 describes the utter devastation of crops, men and beasts, and trees. But no hail fell in the land of Goshen, where the Israelites were.
God wasn’t done with Nut (the sky goddess), Osiris (the crop fertility god) and Set (the storm god). Exodus 10:12-20 describes how a plague of locusts devoured the remaining crops of wheat and rye, ensuring there would be no harvest in Egypt that year.
The ninth plague is described in Exodus 10:21-29. The three days of darkness was aimed at the sun-god, Ra (or Re), one of the chief deities of Egypt. Ra was symbolized by Pharaoh himself.
Exodus chapter 11 describes the tenth and last plague, the death of the firstborn Egyptian males, which was a judgment on Isis, the protector of children. This was the ultimate disaster since all the plans and dreams of a father were bound up in his firstborn son.
The New International Study Bible notes explain how the first, the fourth and seventh plagues were introduced by a warning, delivered to the Pharaoh in the morning as he went out to the Nile. He and his gods were powerless in the face of the creator, who exposed those false gods as impotent.
Sources: https://www.gotquestions.org/ten-plagues-Egypt.html
https://carm.org/what-type-god-would-kill-firstborn-egypt
https://answersfromthebook.org/2011/02/28/the-living-god-vs-the-gods-of-egypt/
Autodidact Egyptologist Yisroel Cohen addresses this at length in Chapter 12 of Mitzrayim, Midrash and Myth.
James Hoffmeier lists a number of theories in his book here, one of the very many sources that Cohen brings on page 219, fn 372. The possibilities seem to be that the plagues targeted a single god, all of the animal gods, all of the gods, or whichever gods we can associate with each plague
Cohen himself lists the following potential connections:
Dam, blood - Based on Zohar Shemot 18a-b, it seems that all of the Nile gods (Hapi/H'pi, Osiris, Khnum, Anuket/Anukis, Sobek) were targeted. Cohen adds that water gods (Nephthys, Tefnut) and fish gods (Hatmehyt) were also attacked.
Tzefarde'a, frogs or crocodiles - depending on the understanding of this plague, it targeted either Heqet, the fertility/frog-headed goddess and god Kuk, who also had the appearance of a frog, or Sobek, the crocodile-headed god.
Kinim, lice - he understands this to be an attack on the earth-god Geb.
Arov, an attack of some kind of animal - this seems to have been aimed at all of the animal gods, including Sekhmet, Bast/Bastet, Babi, Anubis, and Khepri.
Dever, death of livestock - this plague targeted the 3 bull-gods Apis, Mnevis, and Bakha, and other gods associated with livestock, including Hathor, Bat, Khnum, Kherty, Banebdjedet and Heryshaf.
Shechin, boils - this was an attack on Pharaoh's sorcerers, but also invalidated healing gods Sekhmet, Imhotep and Thoth.
Barad, hail - this plague trageted harvest gods Neper, Nepit and Renenutet, as well as other gods, which were supposed to prevent rain.
Arbeh, locusts - according to Cohen, this was a direct attack on Osiris, god of agricultural fertility.
Choshech, darkness - targeted Ra, sun god
Makkat Bechorot, death of the firstborn, was an attempt to frighten Pharaoh, who was worshiped as a god himself (see Chapter 9 of his book, "Pharaoh and Ra"), but also wiped out all of Egypt's gods (see his discussion of this on pages 233-238).