Important Multiple Choice Questions On P block elements class 12 for various entrance examination When SO2 gas is passed through an aci...
Important Multiple Choice Questions On P block elements class 12 for various entrance examination
- When SO2 gas is passed through an acidified solution of K2Cr2O7 :
(a) The solution become blue
(b) The solution become colourless
(c) SO2 is reduced
(d) Green Cr2(SO4) is formed
- Sulphurous anhydride is:
(a) SO2
(b) SO3
(c) HSO3^–1
(d) SO3^–2 - Red phosphorus is chemically uncreative because
(a) It does not contain P – P bonds
(b) It does not contain tetrahedral P4 molecules
(c) It does not catch fir e in air even up to 400ºC
(d) It has a polymeric structure. - Peroxy linkage is present in:
(a) Caro’s acid
(b) Pyrosulphuric acid(c) Sulphurous acid(d) Di thionic acid - In the compound of type ECl3, where E = B, P, As, or Bi, the angle Cl – E – Cl of different E are ion the order :
(a) B > = P = As = Bi
(b) B > P > As > Bi
(c) B < P = As = Bi
(d) B < P < As < Bi
- White phosphorus reacts with caustic soda. The products are PH3 and NaH2PO2. This reaction is an example of :
(a) Oxidation
(b) Reduction
(c) Neutralization
(d) Oxidation and reduction
- PH3 produces smoky rings when it comes in content with air. This is because:
(a) It is inflammable
(b) It combines with water vapour
(c) It combines with nitrogen
(d) It contains impurity of P2H4
- In white phosphorus (P4) molecule which one is not correct ?
(a) Six P – P single bond are present
(b) Four P – P single bond are present
(c) Four lone pair of electron are present
(d) P – P – P bond angle is 60
- Which statement is not correct?
(a) White and red phosphorus reach with chlorine at room temperature
(b) White phosphorus is metastable, while red phosphorus is stable.
(c) White phosphorus is lighter than red phosphorus
(d) White phosphorus is highly poisonous while red phosphorus is not. - In which reaction does SO2 act as oxidizing agent:
(a) Acidified KMnO4
(b) Acidified K2Cr2O7
(c) Acidified C2H5OH
(d) H2S
- The bonds present in N2O5 are:
(a) Only ionic
(b) Only covalentc
(c) Co-valent and co-ordinate
(d) Covalent and ionic
- Skin tunes yellow in contact with concentrated HNO3 because:
(a) Proteins are converted into xantho proteins
(b) Decomposes into two oxides of nitrogen
(c) Reacts with water to form nitric acid
(d) Reacts with water to form two acid
- Fertilizer having the highest nitrogen percentage is:
(a) Calcium cynamide
(b) Urea
(c) Ammonium nitrite
(d) Zammonium sulphate
- All the elements of the oxygen families are
(a) Non-metals
(b) Metalloids
(c) Radioactive
(d) Polymorphic
- Which statement is false for ozone?
(a) It is obtained by silent electric discharge on oxygen
(b) It is a endothermic compound
(c) It can be obtained by the action of ultraviolet rays on oxygen
(d) It cannot be regarded as an allotrope of oxygen
- Oxygen gas can be prepared from solid KMnO4 by:
(a) Dissolving the solid in dil. HCl
(b) Dissolving the solid in conc. H2SO4
(c) Treating the solid with H2 gases
(d) Strongly heating the solid.
- Starch paper moistened with KI solution turns blue in ozon because of:
(a) Iodine liberation
(b) Oxygen liberation
(c) Alkali formation
(d) Ozone reacts with litmus paper
- Ozone molecule is:
(a) Linear
(b) Triangular
(c) Tetrahedral
(d) None of these
- Formula for tear gas is :
a) COCl2
b) CCl3NO2
c) N2O
d) none of these
- Pure silicon doped with phosphorus is a:
a) metallic conductor
b) insulator
c) n-type semiconductor
d) p-type semiconductor
- A brown ring appears in the test for [2007]
a) nitrate
b) nitrite
c) bromide
d) iron
- Which one of the following is the strongest acid?
(a) SO (OH)2
(b) SO2(OH)2
(c) ClO2(OH)
(d) ClO3(OH)
- Fluorine react with water to give :
(a) Hydrogen fluoride and oxygen
(b) Hydrogen fluoride and ozone
(c) Hydrogen fluoride and oxygen fluoride
(d) Hydrogen fluoride, oxygen and ozone
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