\( Ca_{2}B_{6}O_{11}+Na_{2}CO_{3}\overset{\Delta }{\rightarrow} \left [ X \right ]+CaCO_{3}+NaBO_{2} \) (unbalanced equation) correct choice(s) for [X] is/are
1
Structure of anion of crystalline [X] has one boron atom \( sp^{3} \) hybridised and other three boron atoms \( sp^{2} \) hybridised
2
X with NaOH (aq) gives a compound which on reaction with hydrogen peroxide in alkaline medium yields a compound used as brightener in soaps
3
hydrolysis of [X] with HCl or \( H_{2}SO_{4} \) yields a compound which on reaction with HF gives fluoroboric acid.
4
[X] on heating with chromium salts in oxidising flame gives green coloured bead in cold.