You can talk about the electronegativity (EN) of bonds(each bond in a molecule) but I don't know that there is a total EN for molecules.
For PO3, the P atom has EN of 2.1 and O has 3.5, the difference is 1.4. For the H2S molecules, the H-S bond EN difference is 0.4. For the O2 molecule or H2 molecule or N2 molecules the difference (of course) is zero.
As a general rule a bond is about 50% ionic/50% covalent if the EN difference is 1.8 or so. Also, if we are labeling compounds as ionic or covalent, we call those over 1.8 or 1.9 ionic and those under 1.8 or 1.9 covalent. So N2, O2, H2 etc with a zero difference are non-polar covalent, PO3 is near the 50/50 line so the PO3 bond would be a polar covalent bond (actually a little more covalent than 50% and a little less ionic than 50%). I would classify K2O with a difference of 2.7 as ionic. The H-S bond in H2S is almost purely (but not quite) covalent.
Could you please explain how electronegativity works and how you find the total electronegativity value of
PO3
K2O
H2S
GIVEN: P- 2.1, O-3.5, K- 0.8, H- 2.1, and S- 2.5
Also how to you tell if the compound is ionic, polar covalent, or non polar covalent?
Thank you!!!
2 answers
Which of the following statements describes why ion exchange of 99% SiO2 - 1% B2O3 in a salt bath of molten postassium chloride (KCl) is not an effective way to increase the surface strength of the glass sample?
The ion exchange works correctly, however both air-cooling and water-quenching are more efficient ways to induce a surface strengthening effect.
The glass is composed of only 1% B2O3, which is not a large enough proportion of B2O3 to undergo ion exchange, and therefore does not increase the surface strength of the sample effectively.
The potassium ion is smaller than B2O3, so when ion exchange takes place the surface is actually being weakened instead of strengthened.
The sample described above is composed of SiO2 and B2O3. Neither of these components are network modifiers, so ion exchange does not take place to strengthen the surface of the glass.
The surfaces of the glass sample are not cooled quickly enough to create a high internal strain energy that leads to strong surfaces.
The ion exchange works correctly, however both air-cooling and water-quenching are more efficient ways to induce a surface strengthening effect.
The glass is composed of only 1% B2O3, which is not a large enough proportion of B2O3 to undergo ion exchange, and therefore does not increase the surface strength of the sample effectively.
The potassium ion is smaller than B2O3, so when ion exchange takes place the surface is actually being weakened instead of strengthened.
The sample described above is composed of SiO2 and B2O3. Neither of these components are network modifiers, so ion exchange does not take place to strengthen the surface of the glass.
The surfaces of the glass sample are not cooled quickly enough to create a high internal strain energy that leads to strong surfaces.