What is the difference of dipole moment of NH3 and NF3 respectively?

 Both NH3 and NF3 have sp3 hybridization and trigonal pyramidal shape.

Fluorine has more electronegative than nitrogen but NH₃ has more dipole moment than NF₃.  In NH3, Nitrogen is more electronegative than Hydrogen. So Nitrogen pulls the electrons from Hydrogen towards itself and so, the direction of moment due to the N-H bonds is in the same direction as that of the lone pair of electrons on Nitrogen. Hence here additive effect appears while in case of NF₃, Fluorine is more electronegative than Nitrogen. So fluorine pulls electrons from nitrogen towards itself  so that direction of moment due to N-F bonds is in the opposite direction as the lone pair of electron on nitrogen atom. Hence it is clear dipole moment of NH₃ is more than NF₃.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) Why dipole moment of NH3 is lower than NH3?

Why dipole moment of NH3 is lower than NH3?

Both NH3 and NF3 have sp3 hybridization and trigonal pyramidal shape.

Fluorine has more electronegative than nitrogen but NH₃ has more dipole moment than NF₃.  In NH3, Nitrogen is more electronegative than Hydrogen. So Nitrogen pulls the electrons from Hydrogen towards itself and so, the direction of moment due to the N-H bonds is in the same direction as that of the lone pair of electrons on Nitrogen. Hence here additive effect appears while in case of NF₃, Fluorine is more electronegative than Nitrogen. So fluorine pulls electrons from nitrogen towards itself  so that direction of moment due to N-F bonds is in the opposite direction as the lone pair of electron on nitrogen atom. Hence it is clear dipole moment of NH₃ is more than NF₃.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) What is the difference of dipole moment of NH3 and NF3 respectively?

Which NH3 and NF3 have the highest dipole moment and why?

Both NH₃ and NF₃ have sp3 hybridization and trigonal pyramidal shape.

                     

Fluorine has more electronegative than nitrogen but NH₃ has more dipole moment than NF₃.  In NH3, Nitrogen is more electronegative than Hydrogen. So Nitrogen pulls the electrons from Hydrogen towards itself and so, the direction of moment due to the N-H bonds is in the same direction as that of the lone pair of electrons on Nitrogen. Hence here additive effect appears while in case of NF₃, Fluorine is more electronegative than Nitrogen. So fluorine pulls electrons from nitrogen towards itself  so that direction of moment due to N-F bonds is in the opposite direction as the lone pair of electron on nitrogen atom. Hence it is clear dipole moment of NH₃ is more than NF₃.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) What is the difference of dipole moment of NH3 and NF3 respectively?

Which has more dipole moment of NH3 or NF3?

Both NH₃ and NF₃ have sp3 hybridization and trigonal pyramidal shape.

                        

Fluorine has more electronegative than nitrogen but NH₃ has more dipole moment than NF₃.  In NH3, Nitrogen is more electronegative than Hydrogen. So Nitrogen pulls the electrons from Hydrogen towards itself and so, the direction of moment due to the N-H bonds is in the same direction as that of the lone pair of electrons on Nitrogen. Hence here additive effect appears while in case of NF₃, Fluorine is more electronegative than Nitrogen. So fluorine pulls electrons from nitrogen towards itself  so that direction of moment due to N-F bonds is in the opposite direction as the lone pair of electron on nitrogen atom. Hence it is clear dipole moment of NH₃ is more than NF₃.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) What is the difference of dipole moment of NH3 and NF3 respectively?

Compare the dipole moment of H2O and F2O.

Let’s draw the structure of both two compounds and then analyses it.

In both H₂O and F₂O the structure is quite the same. In H₂O as O is more electronegative than hydrogen so the resultant bond dipole is towards O, which means both the lone pair and bond pair dipole are acting in the same direction and dipole moment of H₂O is high. In case of F₂O the bond dipole is acting towards fluorine, so in F₂O the lone pair and bond pair dipole are acting in opposition resulting in a low dipole.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) What is the difference of dipole moment of NH3 and NF3 respectively?

Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

Both CCl₄ & CHCl₃ have tetrahedral structure but CCl₄ is symmetrical while CHCl₃ is non-symmetrical.

Due to the symmetric.al structure of CCl₄ the resultant of bond dipoles comes out to be zero. But in case of CHCl₃ it is not possible as the presence of hydrogen introduces some dissymmetry.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) Why dipole moment of NH3 is lower than NH3?

 

CO2 has got dipole moment of zero why?

The structure of CO₂is this is a highly symmetrical structure with a plane of symmetry passing through the carbon. The bond dipole of C–O is directed towards oxygen as it is the negative end. Here two equal dipoles acting in opposite direction cancel each other and therefore the dipole moment is zero.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) Why dipole moment of NH3 is lower than NH3?

The Dipole moment of chloromethane is more than fluoromethane. Explain.

Since C-Cl bond is longer than C-F bond, thus it is compensates the lower electronegativity factor of chlorine. Hence dipole moment of chloromethane is more than fluoromethane.

Related Questions:

(1) The Dipole moment of Chloromethane is more than Fluoromethane. Explain.

(2) CO2 has got dipole moment of zero why?

(3) Dipole moment of CCl4 is zero while that of CHCl3 is non zero. explain.

(4) Compare the dipole moment of H2O and F2O.

(5) Which has more dipole moment of NH3 or NF3?

(6) Which NH3 and NF3 have the highest dipole moment and why?

(7) Why dipole moment of NH3 is lower than NH3?

Melting and boiling point and their periodic trends:

 Melting and boiling point:

(A) Melting point: The temperature at which  a solid material changes into the liquid material is called melting point and process is called melting.

(B) Boiling point the temperature at a liquid material changes into its vapour is called boiling point and the process is called boiling. 

(C) Lower atomic volume generally leads to higher density, increases hardness and brittleness, less malleability and ductility.

(D) Trends in groups: 

1- When we move top to bottom in group of S-Block, the melting point and boiling point decrease.

2- When we move top to bottom in all group of d-Block, the melting point and boiling point increases.

 3- While we move IIIA TO VIA Groups, the MP and BP decreases.

 4- While we move VA TO VIIA Groups, the MP and BP increases.

(E) Trends in period: 

When we move from left to right through periodic table the value of MP and BP first increases to maximum after decrease like density.

Related Questions:

(1) What are the Amphoteric metals ? gives Examples.

(2) Name of total metalloids present in periodic table ?

(3) Total numbers of elements which are liquid at normal temperature is ?

(4) What is Mendeleev's periodic table ? give important features and draw back of Mendeleev's table.

(5) What is atomic density ? give the periodicity of atomic density in periods and groups.

(6) Why there are 2, 8 and 8 elements in first, second and third periodic of periods table respectively ? Explain.

(7) In alkali metal group which is the strongest reducing agent in aqueous solution and why?

(8) The electron affinity of sulphur is greater than oxygen. Why?

(9) The first ionization energy of carbon atom is greater than that of boron atom, whereas reverse is true for the second ionization energy. Explain.

(10) The electronegativities of B, Al, Ga are 2.0, 1.5, 1.6 respectively. The trend is not regular. Explain.

(11) Li2CO3 decomposes on heating but other alkali metal carbonates don’t. Explain.

(12) Of all noble metals, gold has got a relatively high electron affinity. Explain.

(13) Ionization energy of Boron is smaller than Beryllium even though effective nuclear charge is higher?

(14) What are the increasing order of ioni radii of first group elements in water ?

(15) What are the increasing order of molar conductivity of first group elements in water ?

Effective Nuclear charge (Z* or Zeff): Slater's rule: Screening effect or Shielding effect

The decrease in the force of attraction exerted by the nucleus on the valence electrons due to the presence of electrons in the inner orbit is called “Screening effect or shielding effect”

Due to shielding effect of inner shell electrons on the outer shell electrons such that valence electrons feel less attraction from the nucleus. This decreased nuclear charge is known as effective nuclear charge (Z* or Zeff)

The Slater’s  rule determine the actual charge felt by an electron and also allow you to estimate the effective nuclear charge Zeff  from the real number of protons in the nucleus and the effective shielding of electrons in each orbital "shell"

“Slater defined Z* or Z_eff (effective nuclear charge) as a measure of nuclear attraction for an electron. Or The magnitude of positive charge “experienced” by an electron in the atom.

                                              Thus Z* =Z-S

Where Z is the (nuclear charge)= The number of protons in the nucleus of an atom,  and S represent the shielding constant and value is greater than zero but less than Z.

Step 1: Write the electron configuration of the atom in the following form:

              (1s) (2s, 2p) (3s, 3p) (3d) (4s, 4p) (4d) (4f) (5s, 5p) . . .

Step (2):  Electron in higher group do not shield the electrons in the lower group.

Step (3): For ns and np valence electrons:

(A) The electrons in same ns and np group contribute 0.35, except the 1s which shield 0.30

(B) Electrons within the n-1 group contribute 0.85

(C) Electrons within the n-2 or lower groups contribute (shield) 1.00

Example(1) :  Calculate the Zeff (Z*) for 4s electron of chromium atom (Slater's Rule)?

Step (4): For nd and nf valence electrons:

(A) Electrons in same nd and nf group contribute 0.35

(B) Electrons in the group to the left contribute 1.00

Shielding constant (S) obtained is subtracted from Z to get Z*

Example(2) :What is the shielding constant (S) experienced by a 3d electron in the bromine atom?

Periodicity in Z* or Zeff:

(A)  In a period: When we move from left to right in period the Z* increases.

2nd (P)	Li	Be	B	C	N	O	F
Z*/Zeff	1.30	1.95	2.60	3.25	3.90	4.25	5.20

 

(B)  In a Group: When we move from top to bottom the Z* remains constant,

1st gp	Li	Na	K	Rb	Cs
Z*/Zeff	1.30	2.20	2.20	2.20	2.20

Related Questions:

(1) What are the Amphoteric metals ? gives Examples.

(2) Name of total metalloids present in periodic table ?

(3) Total numbers of elements which are liquid at normal temperature is ?

(4) What is Mendeleev's periodic table ? give important features and draw back of Mendeleev's table.

(5) What is atomic density ? give the periodicity of atomic density in periods and groups.

(6) What is atomic volume ? and what is periodicity of atomic volume in groups and periods ?

(7) Why there are 2, 8 and 8 elements in first, second and third periodic of periods table respectively ? Explain.

(8) In alkali metal group which is the strongest reducing agent in aqueous solution and why?

(9) The electron affinity of sulphur is greater than oxygen. Why?

(10) The first ionization energy of carbon atom is greater than that of boron atom, whereas reverse is true for the second ionization energy. Explain.

(11) The electronegativities of B, Al, Ga are 2.0, 1.5, 1.6 respectively. The trend is not regular. Explain.

(12) Li2CO3 decomposes on heating but other alkali metal carbonates don’t. Explain.

(13) Of all noble metals, gold has got a relatively high electron affinity. Explain.

(14 Ionization energy of Boron is smaller than Beryllium even though effective nuclear charge is higher?

(15) What are the increasing order of ioni radii of first group elements in water ?

(16) What are the increasing order of molar conductivity of first group elements in water ?