p block

Question 1

The atomic and ionic radii of the elements of nitrogen, family are smaller than the corresponding elements of carbon family group 14

Answer 1

Due to increase in nuclear charge, while the new electron enters the stream shell as the electrons in the same shell do not shield each other

Question 2

While there is a considerable increase in covalent radius from nitrogen to potassium. However, from arsenic to this bismuth , only a small increase is observed.

Answer 2

Because in each succeeding element, a principal energy cell is added but in the increase of nitrogen to Phosphorus is is due to due to strong ceiling effect of the SMP electrons present in the inner shells. However, the small increase in covalent radius from years to be is due to the poor shielding of the balance electron by the D and F electrons present in the inner shells of this heavier elements.

Question 3

Why the ionisation enthalpy of the elements of group 15 higher than those of the colours bonding elements of group 14?

Answer 3

Because of increased nuclear charge and reduce atomic radii and stable half an electronic configuration. The valance electrons of group 15 elements are strongly attached by the nucleus and has and hence they have less tendency to lose electrons.

Question 4

Group 15 elements are more electronegative than group 14 elements and why does the elements of group 15 show a gradual decrease on moving down the group

Answer 4

Due to smaller atomic size and smaller number of electrons needed to attain noble gas configuration, the elements of group 15 or more electronegative as compare to the woes of group 14

Question 5

Why are the elements of group 14 elements of group 14?

Answer 5

Due to increased nuclear charge and high electronegativity, the elements of group 15 less metallic than the corresponding elements of group of 14 And while moving down the group electronegativity decreases so the metallic characteristic also increases bcuz of the Valance electron are  lost more readily.

Question 6

The melting point of group 15 elements, first increase from nitrogen to arsenic And then decrease to Bismuth

Answer 6

in the decrease between the antimony and bismuth is because of the tendency to form three covalent bonds instead of five covalent bond due to inert pair effect this results in weakening of attraction among their atoms. There are lowering their melting point

Question 7

What happens to the boiling point of density of group 15 down the group?

Answer 7

The boiling point increases till sb and then decreases to bi but the density of the elements of group 15 increases regularly from top to bottom

Question 8

name the allotropes of phosphorus and arsenic and antimony

Answer 8

The allotropes of phosphorus or white, red and black phosphorus and the electrodes of arsenic and antimony or yellow and grey

Question 9

Why nitrogen is able to form -3 oxidation state?

Answer 9

Because nitrogen is the smallest and the most electropositive element of this group. So it forms N3 minus nitride ion

Question 10

The tendency of this element is to show -3 oxidation state decreases. Why as we move down the group.

Answer 10

As we move down the group from nitrogen to bismuth due to a gradual decrease in the electronegativity and ionisation and healthy. The -3 oxidation state decreases.

Question 11

The stability of plus 5 oxidation state decreases while that of 3+ oxidation state increases why

Answer 11

Due to inert pair effect, the plus 5for oxygen state of BI is less stable than a plus five oxygen state of Sb The only stable compound of this bismuth having +5 oxidation state is bif5

Question 12

Why does the nitrogen show all the oxidation state from -3to +5 

Answer 12

Due to small size, high electronegativity, strong tendency to form ppi-ppi multiple bonds

Question 13

Why does nitrogen only possesses maximum covalent C of four?

Answer 13

Since nitrogen does not possess is D orbitals in its valance shell, therefore, it can show a maximum covalent C of four and that too when it donates its lone pair of electrons

Question 14

Why the boiling point of NH3, abnormally high?

Answer 14

Due to intermolecular H bonding because NH bonds are polar

Question 15

Why does the boiling point increases regularly from PH3 to bih3

Answer 15

Due to van walls forces and the force of attraction, higher van der walls force of antimony and bismuth compensates the increase in boiling point of NH3 because of H bonding

Question 16

Why the thermal stability of the Tri hydrides of group 15 decreases as we go down the group?

Answer 16

👍🏻In other words, the H bond strength decreases. Hence, the thermal stability goes on decreasing as we move down the group.

Question 17

As we move down the group, why does the reducing character increases in group 15?

Answer 17

As the thermal stability of the hydrides decreases, the tendency to librate hydrogen increases. Hence, reducing character increases, therefore NH3 being most stable is not a good reducing agents

Question 18

Why does the basic nature decreases down the group of hydrides of group 15? 

Answer 18

As the size of central atom increases, the lone pair of electron occupies is a larger volume. Therefore the electron density on the central atom decreases so its tendency to donate a pair of electron decreases. Hence, the basic strength decreases as we move down the group.

Question 19

Why does the bond angles pf the trihalides of an element decreases. As the electronegativity of the halogen increases.

Answer 19

The electronegativity of halogen increases the bond pairs move away from the central atom. As a result, bond pair, bond pair repulsion decrease. Hence, the bond angles also decrease

Question 20

trihalides of N are the least stable NF3 is however stable NCL3 is explosive well NBR3 and NI3 unknown as there on stable ammoniates NI3.NH3 are only stable moist

Answer 20

Their instability is due to the weakness of NX bond due to a large difference in the size of Nand X atom

Question 21

Why does nitrogen makes ppie p pie multiple bonds?

Answer 21

Because of a small size high electronegativity of

Question 22

Properties of dinitrogen

Answer 22

It is colour less tasteless and non-toxic. it has 2 istopes 14N and 15N and it is inert and an unreactive at room temperature due to its high bond dissociation and helping with the help of a litmus it gives neutral colour

Question 23

How does the ammonium gas is dried?

Answer 23

The moisture present in ammonia may be removed by passing it through a glass tower packed with quicklime

Question 24

Properties of ammonia

Answer 24

It is a colourless gas with gives a pungent smell, ammonical smell It is lighter than air. It is extremely soluble in water and it can be easily liquefied by cooling under pressure. Structure of ammonia is pyramidal geometry. It has a basic nature and turns red litmus blue. It is as same as water due to hydrogen bonding

Question 25

How the final product of nitric acid is found by the ostwalds process

Answer 25

Nitric oxide has formed is recycled and the The nitric acid is Concentrated buys by distillation to give 68% HN03 by mass for the concentration to 98% can be achieved by dehydration with concentrated H2 SO4

Question 26

H N.03 can react to 

Answer 26

It reacts with metallic oxide ,hydroxide carbonates and bicarbonate, giving only one series of salt called nitrates

Question 27

Action of metals with nitric acid 

Answer 27

It does not react with gold and platinum and reaction with metal which are more electropositive than hydrogen liberates nascent hydrogen which further reduces nitric acid gives away righty of reduction products in general more. The dilution greater is the extent of reduction

Question 28

Passivity of HNO3

Answer 28

When dipped in concentrated HN03 metals like iron, chromium, nickel and aluminium lose their normal activity and become passive. This passivity of this metal is due to the formation of then productive layer of metal oxide on the surface of metal which prevent further action.

Question 29

How does noble metals like gold and platinum react with concentrated HN03?

Answer 29

These metal dissolve in aqua Regia three parts of concentrated HCL plus one part of concentrated HN03 forming the respective chloride is HCL first reacts with HN03 to produce Nascent chlorine, which then react with noble metals, forming the respective chloride

Question 30

Explain nitration of organic compound with HN03

Answer 30

A mixture of concentrated HN03 and continuous H2SO4, also called nitrating mixture is used for introducing one or more NO2 groups into the benzene ring. This process called nitration

Question 31

Action on proteins of nitric acid

Answer 31

Nitric acid also reacts with proteins. Giving a yellow compound called XANTHOPROTEIN . It is because of this reason that nitric acid turns the skin as well as will yellow

Question 32

Why the white phosphorus is also called yellow phosphorus

Answer 32

On exposure to light white phosphorus dance hello there for it is also called yellow phosphorus

Question 33

Why the white phosphorus is also called yellow phosphorus

Answer 33

On exposure to light white phosphorus dance hello there for it is also called yellow phosphorus

Question 34

Properties of white phosphorus

Answer 34

It is a soft translucent, maxi, white solid with garlic odour It is very poisonous person working With white phosphorus develops a disease known as foresee, Jo in which job bones decay The melting and boiling point of white phosphorus is very low due to weak wonder, walls, force of attraction Insoluble in water but soluble in organic solvent. Such a CS2 alcohol and ether  It is also strong reducing agent. It reduces HN03 to NO2 and H2SO4 to SO2

Question 35

White phosphorus, show phosphorescene and why?

Answer 35

Since PPP angle is much smaller than the normal tetrahedral angle of the P four molecules are highly strained. Due to this angle strain white phosphorus is very reactive. It readily catches fire in air with greenish glow which is visible in the dark. this phenomenon is called phosphorescence.

Question 36

Why white phosphorus is kept in water?

Answer 36

Due to its very low ignition temperature about 303 K or 30 Celsius, it is always kept under water because it reacts with air

Question 37

How does matchboxes work with white phosphorus or P4S3?

Answer 37

P-4 S3 is the most stable sulphide. It is used in strike anywhere matches matches contain P4S3 KCLO3 fillers and glue the friction between the match understand people on the side of the match box initiates a violent reaction between P4S3 and KCLO3 this generates sufficient heat which causes matchstick to burst onto flame.

Question 38

Properties of red phosphorus

Answer 38

It has a polymeric structure joined together through covalent bonds because a polymeric subjects melting point is much higher than of white phosphorus It is hard crystal and orderless, solid, non-poisonous insoluble in water as well as in organic solvent. It is the relatively stable Island top of phosphorus at room temperature. Its ignition temperature is much higher than white phosphorus. It is denser than white phosphorus. It is less reactive than white phosphorus It only reacts with halogen, sulphur, alkali matters only when heated forming their corresponding salt 

Question 39

Conversion of red, phosphorus into white phosphorus

Answer 39

Its sublimes on heating giving papers, which are the same as given by white phosphorus. When this paper contains white phosphorus, obtain this, give us a simple method of re-converting read, phosphorus into white phosphorus.

Question 40

Properties of alpha-black phosphorus 

Answer 40

It can be sublimed in Airbhas an Opaque monoclinic or rhombohedral crystals. It is very stable. I will drop of phosphorus. It does not oxidise in air until heated very strongly. It does not conduct electricity and it is made from red phosphorus at 803 Calvin

Question 41

Properties of beta black phosphorus

Answer 41

It has a graphite like structure and strongly born the atoms in adjacent layers It is a highly polymer iced form of phosphorus and has black metallic lustre It has a sharp melting point of 860 kelvin and specific gravity. 2.69 like graphite. It is a fairly good conductor of electricity.  It is thermodynamically , the most stable allotrope of phosphorus and does not burn in add up to 673 Calvin

Question 42

why a current of carbon dioxide, a coal gas or oil gas is passed through the flask to displace air

Answer 42

pure phospine is not inflammable, but the gas produced usually catches fire in air due to presence of impurity of diphosphine which is usually highly inflammable. There for a current oil gas is passed to the flask to displace it.

Question 43

Explain the structure of phosphine

Answer 43

Same as NH3, but the HPH bond angle PH3 is however much lower than that in NH3 due to less repulsion between bond pairs. Further due to bigger size of p then N, PH bond length is longer then NH bond length.

Question 44

Properties of phosphine

Answer 44

It is a colourless gas, unpleasant or odour similar to that of a garlic or rotten fish and is highly poisonous. It is slightly soluble in water and more soluble in CS to another organic solvents.

Question 45

Why the bond angle of PCL3 is greater than PH3

Answer 45

It is greater than in PH3 due to steady crowding of the 2CL atoms The PCL bond is much longer than the PH bond due to bigger size of the CL atom 

Question 46

Why the oxides of phosphorus have cage structures and exist in dimers 

Answer 46

Due to large size and lower electronegativity phosphorus does not form Ppi multiple bonds

Question 47

PH3 is basic in nature

Answer 47

PH3, we can react with acid like aHI also has a lone pair of electrons. Hence it acts as a Lewis bass

Question 48

Why does PCL three fume in moisture?

Answer 48

PLCL3 on hydrolysis gives fumes of HCL

Question 49

The atomic read out the elements of group16 or smaller than those of the corresponding elements of group 15

Answer 49

Due to the increased nuclear charge of the group 16 elements which results in greater attraction of the electrons by the nucleus. The increase in atomic radii of the group 16 element down the group is primarily due to the increase in the number of electron shells.

Question 50

The first ionisation enthalpy is of the elements of group 16 unexpectedly lower while the second ionisation enthalpy are higher than those of the corresponding elements of group 15

Answer 50

In the first ionisation enthalpy group 16 element is lower than those of the group 15, despite the smaller, atomic radius and higher nuclear charge This is due to because of symmetry group 15 elements or more symmetrical then group 16 elements in the first ionisation enthalpy. The second animation and therapy of the oxygen family is how are higher than those of the nitrogen family. Because after the removal of the first electron, the second electron has to be removed from a more symmetrical exactly and stable electronic configuration of 

Question 51

The first ionisation enthalpy is of the elements of group 16 unexpectedly lower while the second ionisation enthalpy are higher than those of the corresponding elements of group 15

Answer 51

In the first ionisation enthalpy group 16 element is lower than those of the group 15, despite the smaller, atomic radius and higher nuclear charge This is due to because of symmetry group 15 elements or more symmetrical then group 16 elements in the first ionisation enthalpy. The second animation and therapy of the oxygen family is how are higher than those of the nitrogen family. Because after the removal of the first electron, the second electron has to be removed from a more symmetrical exactly and stable electronic configuration of 

Question 52

Electron gain enthalpy of group 16

Answer 52

The elements of group 16 have two electrons less than the nearest noble gas configuration. Therefore, they have a high tendency to accept two additional electrons. Hence large negative electron gain enthalpy is next only to head a Jules oxygen has the least electronegative in this group. This is due to its small size. The electron electron replusion in the relatively small to be subset a comparatively large. Hence, the income of electrons are not expected excepted in with the same as in case of other elements of this group. 

Question 53

electronegativity of group 16 have higher values of electronegativity than the group corresponding elements of group 15

Answer 53

This is due to smaller atomic size of group 16 elements as compare to those of group 15 elements and elements of group 16, only need 2 electrons only need two electrons. While those of group 15 need three electrons to attain the stable noble gas configuration.

Question 54

Metallic character of group 16

Answer 54

Because of high ionisation enthalpy values, the elements of 16 a less metallic. However, as we move down the group, the ionisation enthalpy decreases. Hence, the metallic character increases.

Question 55

Why the melting point of Polonium are lower than the those of tellurium

Answer 55

Due to maximum number of inter-meaning, DNF electrons, the inert pair effect is maximum in Pollinium consequently, the S electron in polonium are less available as compare to those in Te as a result van der walls force of attraction will be weaker in PO than in TE there for melting and boiling point of PO will be lower than that of TE

Question 56

Oxygen exist as diatomic gas and other elements exist as octaatomic solids

Answer 56

Oxygen Forms PPPP double bond with other oxygen atom to form diatomic molecules. The intermolecular forces of attraction between oxygen molecules are weak. There for the exist as diatomic gas at room temperature The rest of the rest of elements of this group do not form P by pi pi multiple want to do the largest size and do not exist as diatomic molecules. Instead they prefer to form a single bond of complex structures. 

Question 57

Why does sulphur forms stronger people I D pie bonds, then the larger elements in the group

Answer 57

S and other elements of this group possesses the orbital is hence form P by D for multiple multiple bonds to open effective by the pie overlap. The size of the d orbital must be similar to that of p orbital

Question 58

Why does the sulphur has a stronger tendency for catenation then oxygen?

Answer 58

Due to small size, the lone pair of electrons on the oxygen atoms repel the bond pairs of 001 to a greater extent than the lone pairs of electrons on the sulphur atoms in SS bond. Hence sulphur has a much stronger tendency for academicians and oxygen.

Question 59

Describe oxidation state of group 16

Answer 59

The tendency to show -2 oxidation state decreases from S to po The stability of +6 oxidation state decreases down the group while the stability of +4 increases down the group  Compounds having +4 oxidation state show both oxidising and reducing properties. While compounds having +6 oxidation state only show oxidising property.

Question 60

Why the bond angle decreases down the group of hydrides of group 16?

Answer 60

Due to strong alone by lone pair then bond pair bond pair repulsion. The bond angle in water decreases from the tetrahedral value. As we move down the group from O to Te. The size of the central atom goes on increasing and its electronic negativity goes on decreasing. As a result, the position of two bond pairs is away and away from the central atom. As it moves from H2O to H2te So the repulsion between the bond pairs decreases as as we move down the group 

Question 61

Explain the volatility and boiling point of the hydride of group 16

Answer 61

The higher boiling point of H2O is due to strong intermolecular. H bonding. Since all the other elements have much lower electronegativity than O Then all element do not undergo H bonding however the size of the atom increases regularly from 0 TO TE therefore wonder world polls says of attraction increases with increase in the molecular size. Hence the boiling point increases gradually from H2S TO H2SE

Question 62

Why the acidic strength increases down the group of hydrides of group 16?

Answer 62

As the atomic size increases down the group, the bond length increases. Hence the bond strength decreases. Consequently, the cleavage of EH bond becomes easier. As a result the tendency to release hydrogen as proton increases. That is the acidic strength increases down. The group has H2Ois less least acidic and H2Po is most acidic.

Question 63

Why does SF6 does not go under hydrolysis?

Answer 63

A subject is a colour less or less and non-toxic gas at room temperature. It is thermally stable and chemically inert. Its chemical inertness is due to the reason that the 6F atoms protect the sulphur atom from attack by the regions to such an extent that even thermodynamically most favourable reaction like hydrolysis do not occur.

Question 64

Explain the order of hydrolysis of hexafluoride

Answer 64

As the size of atom increases, the electronegativity decreases and the bond bond polarity increases leading to increase in reactivity or decreasing stability down the group. 

Question 65

Group 18 noble gas Explain the electron gain enthalpy down the group

Answer 65

Noble gases have completely fresh options. As a result there is no vacant room in the valance orbital. Hence the additional electron has a place in the orbital of next higher shelf energy has to be supplied to add an additional electron. Hence the electron gain enthalpy of noble gases positive the tendency to accept an electron decreases and hence the electron gain enthalpy decreases from neon to radar and however because of a small size helium has much higher tendency to accept an additional electrons. Hence, its electron gain enthalpy is less Positive.