MCQ
The product obtained when silica reacts with hydrogen fluoride is
- A$SiF_4$
- ✓$H_2SiF_6$
- C$H_2SiF_4$
- D$H_2SiF_3$
✓
Answer
Correct option: B.
$H_2SiF_6$
b
The final product formed when silica $\left(\mathrm{SiO}_{2}\right)$ reacts with hydrogen fluoride $(\mathrm{HF})$ is $\mathrm{H}_{2} \mathrm{SiF}_{6} .$
The final product formed when silica $\left(\mathrm{SiO}_{2}\right)$ reacts with hydrogen fluoride $(\mathrm{HF})$ is $\mathrm{H}_{2} \mathrm{SiF}_{6} .$
The reactions are as follows:
$\mathrm{SiO}_{2}+4 \mathrm{HF} \rightarrow \mathrm{SiF}_{4}+2 \mathrm{H}_{2} \mathrm{O}$
$3 \mathrm{SiF}_{4}+4 \mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{H}_{2} \mathrm{SiF}_{6}+\mathrm{H}_{4} \mathrm{SiO}_{4}$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
$5.1\, g\, NH_4SH$ is introduced in $3.0\, L$ evacuated flask at $327\,^oC$. $30\%$ of the solid $NH_4SH$ decomposed to $NH_3$ and $H_2S$ as gases. The $K_p$ of the reaction at $327\,^oC$ is
→($R = 0.082\, L\, atm\, mol^{-1}\, K^{-1}$, Molar mass of $S = 32\, g\, mol^{-1}$, molar mass of $N = 14\, g\, mol^{-1}$)
Which of the following shape can not be obtained from trigonal bipyramidal geometry
Match List$-I$ with List$-II$
→| List$-I$ | List$-II$ |
| $(A)$ Chloroform and Aniline | $(I)$ Steam distillation |
| $(B)$ Benzoic acid and Napthalene | $(II)$ Sublimation |
| $(C)$ Water and Aniline | $(III)$ Distillation |
| $(D)$ Napthalene and Sodium chloride | $(IV)$ Crystallisation |
$10$ $d{m^3}$of ${N_2}$ gas and $10$ $d{m^3}$ of gas $X$ at the same temperature contain the same number of molecules. The gas $X$ is
→The enthalpy of vapourisation of a liquid is 30kJ mol-1 and enthalpy of vapourisation is 75J mol-1. The boiling point of the liquid at 1atm is:
One mole of $NaCl$ $(s)$ on melting absorbed $30.5\,kJ$ of heat and its entropy is increased by $28.8\,J\,{K^{ - 1}}$. The melting point of $NaCl$ is ............. $\mathrm{K}$
→Following data is known about melting of a compound $AB$. $\Delta H = 9.2\,kJ\,mo{l^{ - 1}}$, $\Delta S = 0.008\,kJ\,{K^{ - 1}}\,mo{l^{ - 1}}$. Its melting point is
→The oxidation state of chromium in the final product formed in the reaction between KI and acidified potassium dichromate solution is:
Which of following orders is correct for heat of hydrogenation of these compounds ?
An aqueous solution of $6.3\, g$ of oxalic acid dihydrate is made up to $250\, ml$. The volume of $0.1\, N\, NaOH$ required to completely neutralise $10\, ml$ of this solution is.......$ml$
→