Which of the followings are Lewis acids: `H_(2)O, BF_(3), H^(o+)` and `NH_(4)`?

Answer

`BF_(3),H^(+),NH_(4^(+))`

Explanation

Lewis acids are those acids which can accept a pair of electrons. For example, `BF_(3)`, `H^(+)`, and `NH_(4)^(+)` are Lewis acids.