Question

Determine the electronegativity between the atoms of each molecule.

Identify the bond as either ionic or covalent.
State whether the molecule is polar or non polar.

Identify the structure as having hydrogen bonding, dipole-dipole moments or London dispersion forces (LDF).

Answer 1

i need these 4 questions for 4 elements: H2O, NH3, CH4, and CO2

Answer 2

An ionic bond is formed when one atom accepts or donates one or more of its valence electrons to another atom. A covalent bond is formed when atoms share valence electrons. The atoms do not always share the electrons equally, so a polar covalent bond may be the result.

Answer 3

so which element has covalent bonds?

Answer 4

i think all of them

Answer 5

It'll probably help to look at the Lewis structures of these compounds, as well as an electronegativity chart (all of which you can find online).

Answer 6

The ones with covalent bonds are the ones that share their electrons

Answer 7

so all of them?

Answer 8

i already have all the lewis structures in front of me

Answer 9

Yes all are covalent bonds of some sort

Answer 10

ok, and im really having trouble with the electronegativity, how do i calculate that

Answer 11

The electronegativity can be found on the periodic table and you subtract the lower one from the higher one

Answer 12

so subtract the atomic number from atomic mass?

Answer 13

No there is a Number on the back of the periodic table that is the electronegativity of the element you can also search it too

Answer 14

and then subtract the electronegativity from the atomic number?

Answer 15

No you subtract the electronegativities between the two elements

Answer 16

im lost.. could you do an example? what two elements are you talking abuit

Answer 17

HF
H has an electronegativity of 2.20
F has an electronegativity of 3.98
3.98-2.20=1.78

Answer 18

ohhh so you always subtract the lesser from the larger? or can you get a negative

Answer 19

I don't think there should be a negative i'm pretty sure it is always larger minus smaller

Answer 20

ok give me a sec to do all 4

Answer 21

If \(\sf \Delta EN>1.7\), then the bond must be ionic.

For deciding whether the molecule is polar or not, you need to consider the geometry of molecule. If it is symmetrical then its non-polar otherwise polar.

Ih any molecule has a hydrogen atom attached to highly electronegative elements like N, O or F, then there are greater chances of hydrogen bonding.

Answer 22

H2O: Polar
CO2: Nonpolar
CH4: Nonpolar
NH3: Polar
im pretty sure im correct

Answer 23

Example, \(\sf NH_3\)

EN of N is 3.04
EN of H is 2.2
\(\sf \Delta EN=3.04-2.2=0.84<1.7\) so the bonds will be covalent

Answer 24

they're all covalent

Answer 25

EN of H2O is 1.24?

Answer 26

EN is for a element.

Answer 27

oh, i meant 1.24 is what i got after i subtactred them

Answer 28

NH3 has a tetrahedral structure with a lone pair, thus it is unsymmetrical and hence has a dipole moment which makes it a polar molecule.

Answer 29

i see

Answer 30

For \(\sf H_2O\) there are 2 O-H bonds, you need to see if O-H bond is ionic or covalent.

\(\sf \Delta EN = 3.44-2.2=?\)

Answer 31

I need to leave now, I'll be back in a hour or so. I'll request @taramgrant0543664 to help you further c:

Answer 32

Yes you were correct about which ones are polar and non polar ones

Answer 33

ok, and i was correct about them all being covalent right

Answer 34

Yes they are only polar and non-polar if they are also covalent

Answer 35

and i did the calculations and this is what i got
H2O: 1.24
CO2: 0.89
CH4: 0.35
NH3: 0.84