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Ionic Formula Calculator
An ionic compound is composed of cations and anions joined together. Such compounds are held together by electrostatic forces, and adopt structures that maximize the attraction of oppositely charged species and minimize the repulsion between charged species with the same sign.

Ionic Formula Calculator calculates the ionic formula of the given chemical compound in words.
Default chemical compound is given in the calculator below. The calculator will identify the element location in the periodic table and combine the anion and cation. When you click on "Ionic Formula", you can see the ionic formula for the specified compound.

Steps for Ionic Formula Calculator

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Step 1 :  

Read the problem carefully and identify the location of its element in periodic table.

Step 2 :  

Combine the cation and anion to form an electrically neutral compound.

Problems on Ionic Formula Calculator

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  1. Write the formulas for ionic compounds of an aluminum cation and each of the following anions.

    1. Fluoride ion
    2. Sulfide ion
    3. Nitrate ion

    Step 1 :  

    An aluminum cation is predicted to have a charge of +3 because Al is a metal in Group 3A.

    1. Fluorine is a Group 7A element

    2. Sulfue is a nonmetal in Group 6A

    3. The nitrate ion has the formula NO2-

    Step 2 :  

    1. The charge of the fluoride ion is predicted to be -1. Therefore we need 3F- ions to combine with one Al3+. The formula of the compound is AlF3.

    2. Sulfur forms -2 anion. Thus we need to combine two Al3+ ions with S2- ions. The compound has the formula Al2S3.

    3. In this case the answer is similar to AlF3, and the formula is Al(NO3)2. Here we place parentheses around NO3 to show that three polyatomic NO3- ions are involved.

    Answer  :  

    The ionic formula are listed below.

    AlF3, Al2S3, Al(NO3)2

  2. The ionic compound used in some sidewalk de-icers is made from calcium and chlorine. What formula would represent that compound?

    Step 1 :  

    Calcium belongs to Group IIA, it will form ions with a charge of +2. Chlorine is in Group VIIA and so will tend to form ions with a charge of -1.

    Step 2 :  

    To form an electrically neutral ionic compound, there must be two chloride ions for every calcium ion. Therefore the formula will be CaCl2.

    Answer  :  

    The ionic formula for the compound is CaCl2.

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