Identify the correct statement.
Gypsum is obtained by heating plaster of Paris
Plaster of Paris can be obtained by hydration of gypsum
Plaster of Paris is obtained by partial oxidation of gypsum
Gypsum contains a lower percentage of calcium than plaster of Paris
Which of the following elements is extracted commercially by the electrolysis of an aqueous solution of its compound?
Cl
Br
Al
Na
A certain compound (X) when treated with copper sulphate solution yields a brown precipitate. On adding hypo solution, the ppt. turns white. The compound (X) is
K2CO3
KI
KBr
K3PO4
An example of a double salt is
bleaching powder
K4[Fe(CN)6]
hypo
potash alum
Which of the following statements is false?
Radon is obtained from the decay of radium
Helium is inert gas
Xenon is the most reactive among the rare gases
The most abundant rare gas found in the atmosphere is helium
Which of the following is the electron dedicient molecule?
B2H6
C2H6
PH3
SiH4
The substance used as a smoke screen in warfare is
SiCl4
PCl5
acetylene
Bleaching powder is obtained by the action of chlorine gas and
dilute solution of Ca(OH)2
concentrated solution of Ca(OH)2
dry CaO
dry slaked lime
Al2O3 can be converted into anhydrous AlCl3 by heating
Al2O3 with HCl gas
Al2O3 with NaCl in solid state
a mixture of Al2O3 and carbon in dry Cl2 gas
Al2O3 with Cl2gas
The bleaching action of chlorine is due to
reduction
hydrogenation
chloronation
oxidation
