Chemistry Names and Formulas for Ionic Compounds Flashcards

All ionic compounds must have BOTH POSITIVE AND NEGATIVE IONS.
Also, the charges in any ionic substance must BALANCE...the overall charge of any stable ion MUST BE ZERO

1) Name: ammonium phosphate
2) Solid formula: (NH₄)₃PO₄
3) As balanced, separated ions: 3 NH⁴⁺ + 1 PO₄^3-

The 2 fundamental rules for writing names and formulas are:
1) Write the separated-ions formula first, and
2) Add coefficients that balance the charges

Balancing Separated Ions:
Example: S^2- and Na⁺ combined

1) Write the symbols for the two ions in the compund with their charges, separated by a + sign. (Put positive ion first) Na⁺ + S^2-
2) Coefficients are the numbers in front of the ion or particle. The COEFFICIENT TIMES CHARGE OF CATION MUST EQUAL COEFFICIENT TIMES CHARGE OF ANION.
Write the whole number coefficient in front of the ion formulas to make the negative and positive charges balance 2 Na⁺ + 1 S^2-
3) Reduce the coefficients to the lowest whole number ratios (in this example they already are)

____Al³⁺ + _____SO₄^2-
2 Al³⁺ + 3 SO₄²
Don't forget to always make sure to reduce the coefficients to lowest whole number ratios!

Writing Separated Ions From Names:
1) Write the symbols for the two named ions, include their charges. Separate them with a + sign
2) Add lowest whole number coefficients to balance the charges
Aluminum carbonate ---> Al³⁺ + CO₃^2- -----> 2 Al³⁺ + 3 CO₃^2-

In ionic solid formulas the charges are NOT shown.
*Write the balanced separated ions first, so taht you can see and balance the charges
Steps:
1) Based on name, write separated ions. Add lowest whole number coefficients to balance charge and draw a -----> For potassium sulfide: 2K⁺ + 1S^2- ------->
2) After the ---->, write 2 ion symbols, positive ion first with a small space between them. Include any subscripts that are part of the ion symbol BUT NO CHARGES or COEFFICIENTS2 K+ + 1S2- -----> K S
3) for after arrow.... put ( ) around polyatomic ion if its coefficient is separated ions formula is more than 1.....since K and S are both monatomic do not add parentheses

4) Add subscripts after each symbol on the right. The subscript will be the same as the coefficient in front of that ion in the separated ions formulaThe K coefficient becomes a solid formula subscript: 2 K⁺ + 1S^2- ----> K₂S
Omit subscripts of 1. For polyatomic ions, write the coefficients as subscripts outside and after the parentheses.

When placed in water, ALL ionic solids dissolve to SOME EXTENT
The DISSOLVED IONS SEPARATE and move about in solution

The dissolving process is represented by a chemical equation with a solid on LEFT and separated ions on RIGHT
Na₃PO_{4 (s)} ----H₂O----> 3Na+_(aq) + 1PO₄^3-_(aq)
The equation must balance atoms and charges and result in correct formulas for ions actually found in solution
To correctly separate solid formulas into ions, you must be able to recognize the ions inside the solid formula.

(s) abbreviation for SOLID STATE
(aq) abbreviation for AQUEOUS STATE which means dissolved in water