Question #dbb08

1 Answer
Feb 16, 2016

Answer:

#F=(Q_1Q_2)/(r^2)#

Explanation:

Coulomb had defined the electrostatic force by:

#F=(Q_1Q_2)/(r^2)#

where, #Q_1 and Q_2# are the charges of the oppositely charged ions and #r# is the distance between the two nuclei.

For example, when comparing the electrostatic forces in two different ionic compounds we consider the following:

#NaCl# and #MgCl_2#:

We look at the difference in charges:

For #NaCl#, the product #Q_1Q_2=(+1)xx(-1)=-1#

For #MgCl_2#, the product #Q_1Q_2=(+2)xx(-1)=-2#

Which means that #F_(MgCl_2)>F_(NaCl)#.

#NaCl# and #CsCl#:

We look at the difference of #r#.

Since #Cs^+# is greater in size than #Na^+# therefore, #r_(CsCl)>r_(NaCl)# and thus #F_(NaCl)>F_(CsCl)#.