posted by steph on .
why is this statement false?
"when an ionic compound dissolves in water an equal number of positive and negative ions is created."
It is true than an equal number of positive and negative CHARGES are formed but that isn't the same as the number of positive and negative ions. For example,
NaCl ==> Na^+ + Cl^-.
1 mole NaCl dissociates, 1 mole Na^+ and 1 mole Cl^- are formed AND 1 mole of + and 1 mole of - negative charges are formed. BUT, when dissociates as in
MgCl2 --> Mg^2+ + 2Cl^-
then you see that we have 1 mole of 2+ charges and 2 moles of 1- charges so the charges are equal; however, we have 1 mole Mg^2+ and 2 moles Cl^-. Again, the charges are equal but the number of + and - ions are not the same.
so then how would you make the statement true?
Read my post again. I told you twice how to make it true.
oh sorrry.....i got it.
when an ionic compound dissolves in water an equal number of positive and negative charges are created.