Solubility and Electronegativity Va
Scientists predict the polarity of the chemical bonds in a substance wing a scale tut
describes the tendency of an element to attract electrons to its atoms when it is combined
with another element. This tendency is called electronegativity. The electronegatiities of
some elements are shown in the table below
H=21
U=10
Na=0.9
K=08
Be=1.5
Mg=1.2
C=10
Electronegativity Values for Some Elements
8=20
Al=15
Ge=16
00 to 04
>04 to <1.0
1.0 to 20
Greater than 2.0
Electronegativity Difference
C=25
Si=18
Ge=18
N=3.0
P=21
As=20
When two elements combine, you can predict which type of bond forms by subtracting
the electronegativities. For example, when hydrogen (H) combines with chlorine (CT), the
difference is 30-2.1=0.9. The chlorine attracts the electrons more than the hydrogen,
use the differences to predict
so the molecule is polar. The following table explains how
the type of bond that forms between two elements.
0=35
5=25
Se=24
Predict Solubility
Use the tables above to answer the following questions.
Type of Bond
Covallent (nonpolar)
Covalent (somewhat polar)
Covalent (very polar
fonic
and Acid/Base Solutions
1. a. Which type of bond forms between potassium (K) and bromine (F)?
b. Will the substance dissolve in water?
F=40
a=30
Br=28
2. a. Which type of bond forms between hydrogen (H) and sulfur (S)?
b. Would the substance be more likely to dissolve in water or a nonpolar solvent?
3. Identify the following bonds as ionic, nonpolar covalent, or polar covalent.
a. H and Br
b. K and Cl
c. C and O
d. Cl and F
e. Li and O
f. II and II
4. Which of the compounds in question 3 would be most likely to dissolve in water?