Laws of Yom Tov Sheini
‘Yom Tov Sheni’ is equivalent to ‘Yom Tov Rishon’ in all its halachot, for everything the Rabbis instituted, is similar to what the Torah commanded.
Thus, all the prohibitions that apply to ‘Yom Tov Rishon’, including Rabbinical prohibitions, also apply to ‘Yom Tov Sheni’. Likewise, all the prayers on ‘Yom Tov Sheni’ are the same as ‘Yom Tov Rishon’.
Also, ‘kiddush’ is recited over wine, and the blessing ‘Shehechiyanu” is recited just like ‘Yom Tov Rishon’ (Shulchan Aruch 661:1). On Pesach, ‘Leyl HaSeder’ is conducted twice – along with all its commandments and blessings. And although, seemingly, there is room to argue that since we observe ‘Yom Tov Sheni’ on account of ‘safek’, in regards to all the blessings, which are of Rabbinical ordinance, one should not recite the blessings, because we have a general rule ‘safek berachot l’hakel’ (when we are not sure whether to make a beracha or not, we refrain form making it), nevertheless, the Rabbisinstructed to recite the blessings, because if blessings are not recited on ‘Yom Tov Sheni’ as they are on ‘Yom Tov Rishon’, people will come to despise ‘Yom Tov Sheni’.