Question

# Write the empirical formula for at least four ionic compounds that could be formed from the...

Write the empirical formula for at least four ionic compounds that could be formed from the following ions:

OH−

,

Fe+2

,

NH+4

,

CrO−24

The ionic compounds are formed between an electropositive and an elrctronegative ion.

The charge of both the ions are balanced in a way that the overall molecule becomes neutral. I.e the net positive charge value should be equal to net negative charge value

1- Fe+2 + OH-

Here net charge on Fe is +2. So to balance it we need net negative charge of -2

So the possible combination is

Fe+2 + 2(OH)- ---------+> Fe(OH)2. Ferrus hydroxide

similarly

Fe+2 and CrO4 2-

Here already we have+2 charge and to balance it a -2 charge

So the possible ionic compound is-

Fe+2 + (CrO4)2- ---------->. Fe(CrO4). Ferous chromate

3-

Similarly

(NH4)+ + OH- -------->. NH4OH Ammonium hydroxide

2 (NH4)+ + (CrO4)2- -------->. (NH4)2(CrO4). Ammoniun chromate