Q.1
The major role of fluorspar (CaF2) which is added in small amount in the electrolytic reduction of alumina dissolved in fused cryolite (Na3AlF6 is
  • a) as a catalyst
  • b) to make the fused mixture very conducting
  • c) to increase the temperature of the melt
  • d) to decrease the rate of oxidation of carbon at the anode
Q.2
Hydrogen gas will not reduce
  • a) heated curic oxide
  • b) heated ferric oxide
  • c) heated stannic oxide
  • d) heated aluminium oxide
Q.3
In the alumino-thermite process, aluminiium acts as
  • a) an oxidising agent
  • b) a flux
  • c) a reducing agent
  • d) a solder
Q.4
Type of bonds present in CuSO4.5H2O are only
  • a) electrovalent and covalent
  • b) electrovalent and coordinate covalent
  • c) electrovalent, covalent and coordinate covalent
  • d) covalent and coordinate covalent
Q.5
Assertion : Ethyl xanthate is used as collector in froth floatation process. Reason: Collector depress the floatation property of one of the components of the ore and thus help in the separation of different minerals present in the same ore
  • a) Both Assertion and Reason are true and the Reason is correct explanation of Assertion
  • b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
  • c) Assertion is true, but Reason is false
  • d) Assertion and Reason are false
Q.6
Iron is renderd passive by treatment with concentrated
  • a) H2SO4
  • b) H3PO4
  • c) HCl
  • d) HNO3
Q.7
Assertion: Calcium is extracted by the electrolysis of fused CaCl2 Reason: Addition of CaF2 increases the fusioon temerature of the electrolyte
  • a) Both Assertion and Reason are true and the Reason is correct explanation of Assertion
  • b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
  • c) Assertion is true, but Reason is false
  • d) Assertion and Reason are false
0 h : 0 m : 1 s