Q: Identify the correct statements from the following :(a) CO2(g) is used as refrigerant for ice-cream and frozen food.(b) The structure of C60 contains twelve six carbon rings and twenty five carbon rings.(c) ZSM-5, a type of zeolite, is used to convert alcohols into gasoline.(d) CO is colorless and odourless gas.

∙ Dry ice, CO2(s), is used as refrigerant∙ C60 contains 20 six membered rings, 12 five membered rings

Q: Match the following and identify the correct option.

∙ Mixture of CO and H2 gases is known as water gas or synthesis gas.∙ Temporary hardness of water is due to bicarbonates of calcium and magnesium.∙ Diborane (B2H6) is an electron deficient hydride.∙ H2O2 is non-planar molecule having open book like structure.

Q: Which of the following is incorrect statement?

PbF4 and SnF4 are ionic in nature.

Q: Which of the following is electron-deficient?

CH3−CH3,SiH3−SiH3 and PH3 contain eight electron in valence shell. In B2H6 molecule sufficient electron are not available for bonding and it contain tricentric bond. So B2H6 molecule is electron deficient.

Q: Which of these is not a monomer for a high molecular mass silicone polymer?

Linear chain silicon form by hydrolysis of Me2SiCl2 followed by condensation. Cross link silicon form by hydrolysis of MeSiCl3. Me3SiCl is used to stop chain lengthMe3SiCl⟶HOHMe3SiOHMe3SiOH+HOSiMe3→Me3Si−O−OSiMe3

Question 1

Identify the correct statements from the following :(a) CO2​(g) is used as refrigerant for ice-cream and frozen food.(b) The structure of C60​ contains twelve six carbon rings and twenty five carbon rings.(c) ZSM-5, a type of zeolite, is used to convert alcohols into gasoline.(d) CO is colorless and odourless gas.

Accepted Answer

∙ 	Dry ice, CO2​(s), is used as refrigerant∙  C60​ contains 20 six membered rings, 12 five membered rings

Question 2

Which of the following is not correct about carbon monoxide ?

Accepted Answer

The carboxyhemoglobin is about 300 times more stable than oxyhaemoglobin.

Question 3

Match the following and identify the correct option.

Accepted Answer

∙  Mixture of CO and H2​ gases is known as water gas or synthesis gas.∙  Temporary hardness of water is due to bicarbonates of calcium and magnesium.∙  Diborane (B2​H6​) is an electron deficient hydride.∙  H2​O2​ is non-planar molecule having open book like structure.

Question 4

Which of the following is incorrect statement?

Accepted Answer

PbF4​  and SnF4​  are ionic in nature.

Question 5

The compound that is most difficult to protonate is :

Accepted Answer

Due to involvement of lone pair of electrons in resonance in phenol, it will have positive charge (partial), hence incoming proton will not be able to attack easily.

Question 6

When copper is heated with conc. HNO3​ it produces:

Accepted Answer

Cu+4HNO3​→Cu(NO3​)2​+2NO2​+O2​

Question 7

Which of the following is electron-deficient?

Accepted Answer

CH3​−CH3​,SiH3​−SiH3​  and PH3​  contain eight electron in valence shell. In B2​H6​  molecule sufficient electron are not available for bonding and it contain tricentric bond. So B2​H6​  molecule is electron deficient.

Question 8

Which of these is not a monomer for a high molecular mass silicone polymer?

Accepted Answer

Linear chain silicon form by hydrolysis of Me2​SiCl2​  followed by condensation. Cross link silicon form by hydrolysis of MeSiCl3​. Me3​SiCl  is used to stop chain length​Me3​SiCl⟶HOH​Me3​SiOHMe3​SiOH+HOSiMe3​→Me3​Si−O−OSiMe3​​

Question 9

It is because of inability of ns2 electrons of the valence shell to participate in bonding that:

Accepted Answer

Inability of ns2  electrons of the valence shell to participate in bonding on moving down the group in heavier p-block elements is called inert pair effectAs a result, Pb (II) is more stable than Pb  (IV)Sn(IV)  is more stable than Sn(II) ∴Pb(IV)  is easily reduced to Pb(II) ∴Pb(IV)  is oxidising agentSn(II)  is easily oxidised to Sn(IV) ∴Sn(II)  is reducing agent.

Question 10

Which of the following is a sink forCO  ?

Accepted Answer

Micro-organisms present in the soil is a sink for CO.

Question 11

The element Z=114 has been discovered recently. It will belong to which of the following family group and electronic configuration?

Accepted Answer

Z=114 belong to Group 14, carbon familyElectronic configuration =[Rn]5f146d107 s27p2

Question 12

Which of the statements given below is incorrect?

Accepted Answer

i. 		No. of electron in ONF = 24No. of electron in NO2−​ = 24			Both are isoelectronic.ii. 	OF2​ is a fluoride of oxygen not oxide of fluorine because EN of fluorine is more than oxygen. OF2​= Oxygen difluorideiii. 	 Cl2​O7​ is an anhydride of perchloric acid.  iv.		O3​ molecules is bent   shape.

Question 13

The stability of +1 oxidation state among Al, Ga, In and TI increases in the sequence:

Accepted Answer

Stability of +1 oxidation state due to inert pair effect TI < In < Ga < Al.

Question 14

How can you explain higher stability of BCl3​ as compared to TlCl3​?

Accepted Answer

B shows +3 oxidation state and can form stable BCl3​. Thallium shows +1 and +3 oxidation state. Due to inert pair effect, +1 oxidation state is more stable than +3 oxidation state. Hence,  BCl3​ is stable but TlCl3​ not.

Question 15

Why does boron triflouride behave as a Lewis acid ?

Accepted Answer

B atom in  BF3​ has 6 valence electrons. To complete octet, it requires 2 electrons. It readily accepts an electron pair from Lewis bases such as fluoride ion, ethoxide ion and behaves as Lewis acid.BF3​+F−→BF4−​

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