Pesachim 7b - Making Berachot "Over Laasiyatan" (Before the Mitzvah), Beracha for Tevila in a Mikveh, Is a Kippah Me'akev Tefillah?

Pesachim Daf 7b - Shiur #30 Machloket Rashi vs Tosafot on why Beracha of Tevilah in a Mikveh When to make the beracha before dipping in a mikveh Berachot before doing the Mitzva (Beracha of a Convert dipping in the Mikveh) If you pray without a kippah, did the tefilah count? Igrot Moshe's opinion. Rav Ben Haim's reason for disagreeing