Tardigrade
Tardigrade - CET NEET JEE Exam App
Exams
Login
Signup
Tardigrade
Question
Chemistry
When sand is heated with hydrofluoric acid and a wet rod is brought in contact with vapours evolving, a white deposit is due to
Q. When sand is heated with hydrofluoric acid and a wet rod is brought in contact with vapours evolving, a white deposit is due to
1984
236
VMMC Medical
VMMC Medical 2004
Report Error
A
S
i
F
4
B
S
i
F
2
C
H
4
S
i
O
4
D
none of these
Solution:
Sand, on heating with HF, give silicon terafluoride vapours, which form silicic acid
(
H
4
Si
O
4
),
on coming in contact with water.
S
i
O
2
+
4
H
F
S
i
F
4
+
2
H
2
O
3
S
i
F
4
+
4
H
2
O
2
H
2
S
i
F
6
+
while
H
4
S
i
O
4