Welcome to Chem Zipper.com......

Search This Blog

Wednesday, July 28, 2021

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.

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.

 

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.


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.





Tuesday, July 27, 2021

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 ?