Eamcet - Chemistry - S Block Elements

In the hardening stage of plaster of paris, the compound formed is :

A.  CaSO4

B.  orthorhombic CaSO4. 2H2O

C.  CaSO4. H2O

D.  monoclinic CaSO4. 2H2O

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In the extraction of sodium by Down's process, cathode and anode are respectively:

A.  copper and nickel

B.  copper and chromium

C.  nickel and chromium

D.  iron and graphite

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Sodium is heated in air at 3000C to form X. X absorbs CO2 and forms Na2CO3 and Y. Which of the following is Y

A.  H2

B.  O2

C.  H2O2

D.  O3

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What are the metal ions present in carnallite ?

A.  Mg, K

B.  Al, Na

C.  Na, Mg

D.  Zn, Mg

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Assertion (A) : K, Rb and Cs form superoxides.Reason (R) ;     The stability of the superoxides increase from 'K' to 'Cs' dueto decrease in lattice energy. The correct answer is

A.  Both (A) and (R) are true and (R) is the correct explanation of (A)

B.  Both (A) and (R) are true but (R) is not the correct explanation of (A

C.  (A) is true but (R) is not true

D.  (A) is  not true but (R) istrue

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Beryllium shows diagonal relationship with aluminium.Which one of the following similarity is not correct

A.  Be2C like Al4Cl3 yields methane on hydrolysis

B.  Be like Al is rendered passive by HNO3

C.  Be(OH)2 like Al(OH)3 is strongly basic

D.  Be forms berylliates and Al form aluminates

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Which one of the following elements reduces NaOH to Na?

A.  Si

B.  Pb

C.  C

D.  Sn

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A mixture of sodium oxide and calcium oxide are dissolved in water,and saturated with excess carbon dioxide gas.The resulting solution is.....It contains.......

A.  basic;NaOH and Ca(OH)2

B.  neutral;Na2CO3 and CaCO3

C.  basic; Na2CO3 and CaCO3

D.  acidic; NaOH and CaCO3

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Which of the following alkali metals has the greatest tendency for the half reaction;  M(g) →M+(aq) + e

A.  Sodium

B.  Lithium

C.  Potassium

D.  Cesium

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