Explain what happens when boric acid is heated.
Explain what happens when boric acid is heated.
On heating orthoboric acid $\left( H _{3} BO _{3}\right)$ at $370 \,K$ or above, it changes to metaboric acid $\left( HBO _{2}\right)$ On further heating, this yields boric oxide $B _{2} O _{3}$.
${H_3}B{O_3}\xrightarrow[{370\,K}]{\Delta }\mathop {HB{O_2}}\limits_{Metaboric\,acid} \xrightarrow[{red\,hot}]{\Delta }\mathop {{B_2}{O_3}}\limits_{Boric\,\,oxide} $
Similar Questions
Aluminium trifluoride is insoluble in anhydrous $HF$ but dissolves on addition of $NaF$. Aluminium trifluoride precipitates out of the resulting solution when gaseous $BF_3$, is bubbled through. Give reasons.
Aluminium trifluoride is insoluble in anhydrous $HF$ but dissolves on addition of $NaF$. Aluminium trifluoride precipitates out of the resulting solution when gaseous $BF_3$, is bubbled through. Give reasons.
Match List$-I$ with List$-II :$
List$-I$
List$-II$
$(a)$ $\mathrm{NaOH}$
$(i)$ Acidic
$(b)$ $\mathrm{Be}(\mathrm{OH})_{2}$
$(ii)$ Basic
$(c)$ $\mathrm{Ca}(\mathrm{OH})_{2}$
$(iii)$ Amphoteric
$(d)$ $\mathrm{B}(\mathrm{OH})_{3}$
$(e)$ $\mathrm{Al}(\mathrm{OH})_{3}$
Choose the most appropriate answer from the option given below :
Match List$-I$ with List$-II :$
| List$-I$ | List$-II$ |
| $(a)$ $\mathrm{NaOH}$ | $(i)$ Acidic |
| $(b)$ $\mathrm{Be}(\mathrm{OH})_{2}$ | $(ii)$ Basic |
| $(c)$ $\mathrm{Ca}(\mathrm{OH})_{2}$ |
$(iii)$ Amphoteric |
| $(d)$ $\mathrm{B}(\mathrm{OH})_{3}$ | |
| $(e)$ $\mathrm{Al}(\mathrm{OH})_{3}$ |
Choose the most appropriate answer from the option given below :
- [JEE MAIN 2021]
In $IIIA$ group, $Tl$ (thalium) shows $+1$ oxidation state while other members show $+3$ oxidation state. Why
In $IIIA$ group, $Tl$ (thalium) shows $+1$ oxidation state while other members show $+3$ oxidation state. Why
The most abundant metal in the earth crust is
The most abundant metal in the earth crust is
The bond dissociation energy of $B- F$ in $BF_3$ is $646 \,kJ\, mol^{-1}$ whereas that of $C - F$ in $CF_4$ is $515\, kJ\, mol^{-1}.$ The correct reason for higher $B- F$ bond dissociation energy as compared to that of $C-F$ is
The bond dissociation energy of $B- F$ in $BF_3$ is $646 \,kJ\, mol^{-1}$ whereas that of $C - F$ in $CF_4$ is $515\, kJ\, mol^{-1}.$ The correct reason for higher $B- F$ bond dissociation energy as compared to that of $C-F$ is
- [AIEEE 2008]