Its a question about Chemistry

Question

 

For each of the following compounds, give the formula, charge, and number of each ion that makes up the compound. (For example, for H2SO4, enter SO4 in the anion box, -2 in the charge box, and 1 in the number box.) (a) KH2PO4 cation charge number anion charge number (b) MgS cation charge number anion charge number (c) CaCl2 cation charge number anion charge number (d) Co2(SO4)3 cation charge number anion charge number (e) Al(OH)3 cation charge number anion charge number

 

 

Any help would be much appreciated. Ive tried to do this but it confuses me so much.

Answer 1

For these, you would need to identify the cation and anion. For these the cations are pretty easy to find, and once you've done that, it's pretty easy to find the anion. It's easier to find if you look at a periodic table. Once, you know the charge of the cation, you can find the charge of the anion, because the charges must balance.

 

a) K is the cation, with a +1 charge, and H₂PO₄ is the anion, with a -1 charge.

 

b) Mg is the cation, charge +2 (it is in column 2 of the periodic table), and S is the anion, charge -2.

 

c) Ca is the cation, charge +2, Cl is the anion, charge -1 (there are 2 in this ionic bond).

 

d) Co is the cation, charge +3, SO₄ is the anion, charge -2 (This one might have been a little tough. The best way to have done this is to know that sulfate has a charge of -2, seeing that there are 3 sulfate anions, and finding the charge of the cobalt cations that way).

 

e)Al is the cation, charge +3, OH is the anion, charge -1 (similar to d, the best way to have done this is to memorize that hydroxide has a charge of -1, and finding the charge of the aluminum ions that way).