Which of the following is not a true alum? from Chemistry The p-

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

91.

C-C bond length is maximum in

  • diamond

  • graphite

  • naphthalene

  • fullerone


92.

Dry ice is

  • Solid H2O

  • Solid CO2

  • Solid N2O4

  • Solid NH3


93.

When borax is heated strongly, it gives

  • BaBO2

  • B2O3

  • B3N3H6

  • Na2B4O7


94.

Sindhur, an oxide of lead, is an example of ............. oxide.

  • basic

  • super

  • mixed

  • amphoteric


Advertisement
95.

The magnetic nature of boron molecule is same as the magnetic nature of

  • nitrogen molecule

  • carbon molecule

  • unipositive nitrogen molecule

  • oxide ion


Advertisement

96.

Which of the following is not a true alum?

  • Na2SO4.Al2(SO4)3.24H2O

  • MgSO4.Cr2(SO4)3.24H2O

  • K2SO4.Cr2(SO4)3.24H2O

  • (NH4)2SO4.Fe(SO4)3.24H2O


B.

MgSO4.Cr2(SO4)3.24H2O

Alums and pseudoalums are the double salts of general formulae M2SO4M'2(SO4)3·24H2O and MSO4(M'2SO4)3.24H2O respectively. Here the point of difference is that in case of pseudoalums, the metal M is bivalent (which in case of alums is univalent).

Thus, MgSO4Cr2(SO4)3·24H2O is a pseudoalum (or not a true alum.)


Advertisement
97.

The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm-3 respectively. If the standard free energy difference is 1895 J mol-1, the pressure at which graphite will be transformed into diamond is

  • 9.92 × 108 Pa

  • 9.92 × 107 Pa

  • 9.92 × 106 Pa

  • None of these


98.

Which one of the following elements does not form triiodide on reacting with iodine?

  • B

  • Ti

  • Al

  • Ga


Advertisement
99.

An example of covalent solid is

  • MgO

  • Mg

  • SiC

  • CaF2


100.

The order of covalent character of KF, KI, KCl is

  • KCl < KF < KI

  • KI < KCl < KF

  • KF < KI < KCl

  • KF < KCl < Kl


Advertisement