Write the formulas of the compound Al+3 formed by specified cations with the following anions:OH-, NO3-, CO3-2,HSO4-, PO4-3 . Use the given order of anions
To determine the formulas of compounds formed by cations with specific anions, you need to consider the charges of the ions involved and balance them.
1. Al+3 with OH-:
The +3 charge of aluminum cation (Al+3) should combine with the -1 charge of hydroxide anion (OH-) to balance the charges. Therefore, the formula of the compound is Al(OH)3.
2. Al+3 with NO3-:
The +3 charge of aluminum cation (Al+3) should combine with the -1 charge of nitrate anion (NO3-) to balance the charges. Since both ions have single charges, they combine in a 1:1 ratio. Therefore, the formula of the compound is Al(NO3)3.
3. Al+3 with CO3-2:
The +3 charge of aluminum cation (Al+3) should combine with the -2 charge of carbonate anion (CO3-2) to balance the charges. To do this, two aluminum cations (+6) combine with three carbonate anions (-6). Therefore, the formula of the compound is Al2(CO3)3.
4. Al+3 with HSO4-:
The +3 charge of aluminum cation (Al+3) should combine with the -1 charge of hydrogen sulfate anion (HSO4-) to balance the charges. Since both ions have single charges, they combine in a 1:1 ratio. Therefore, the formula of the compound is Al(HSO4)3.
5. Al+3 with PO4-3:
The +3 charge of aluminum cation (Al+3) should combine with the -3 charge of phosphate anion (PO4-3) to balance the charges. To do this, one aluminum cation (+3) combines with one phosphate anion (-3). Therefore, the formula of the compound is AlPO4.
Remember to always check that the overall charge of the compound is neutral after combining the ions.
To write the formulas for the compound Al+3 formed by the specified cations with the given order of anions (OH-, NO3-, CO3-2, HSO4-, PO4-3), we need to consider the charges of the cation and anion to balance the overall charge.
1. Al+3 with OH-:
The cation Al+3 has a charge of +3, while the anion OH- has a charge of -1. To balance the charges, we need three OH- anions:
Formula: Al(OH)3
2. Al+3 with NO3-:
The cation Al+3 has a charge of +3, while the anion NO3- has a charge of -1. To balance the charges, we need three NO3- anions:
Formula: Al(NO3)3
3. Al+3 with CO3-2:
The cation Al+3 has a charge of +3, while the anion CO3-2 has a charge of -2. To balance the charges, we need two CO3-2 anions:
Formula: Al2(CO3)3
4. Al+3 with HSO4-:
The cation Al+3 has a charge of +3, while the anion HSO4- has a charge of -1. To balance the charges, we need three HSO4- anions:
Formula: Al(HSO4)3
5. Al+3 with PO4-3:
The cation Al+3 has a charge of +3, while the anion PO4-3 has a charge of -3. To balance the charges, we need one PO4-3 anion:
Formula: AlPO4
So, the formulas of the compounds formed by the specified cations with the given anions are:
1. Al(OH)3
2. Al(NO3)3
3. Al2(CO3)3
4. Al(HSO4)3
5. AlPO4
You should be learning to do this yourself.
Here is the easy way and one you can do in your head.
Al^3+ and NO3^-
In your mind write +3 above Al and write -1 above NO3. Place parentheses around the NO3. Mentally draw an X. The left leg goes from the 3 above Al to the bottom of the parentheses on NO3. Place the 3 at the bottom of that leg. The right leg goes from the -1 above (NO3) to the bottom of the l(ell) on Al. The number 1 goes there and you ignore the - sign.
Al1(NO3)3. You don't need to write a 1 so the formula is Al(NO3)3. All you are doing is transposing the valences of one cation/anion to the other.
Al and CO3 is Al2(CO3)3.
What about Mg and O.
That will give you Mg2O2 BUT always use the lowest numbers; write it as MgO. There are some compounds which don't follow this rule (Hg2Cl2, for example, and a few others) but you will learn those exceptions as you go along.