Provide the formula for the following:
(a). potassium sulfate
(b). sulfur hexafluoride
(c). iron(III) oxide
The correct answer and explanation is:
Here are the formulas and explanations for the given compounds:
(a) Potassium Sulfate (K₂SO₄)
Potassium sulfate is an ionic compound composed of potassium (K) and sulfate (SO₄²⁻) ions. Potassium (K) is an alkali metal and has a +1 charge, while sulfate (SO₄) is a polyatomic ion with a 2- charge. To balance the charges, two potassium ions (K⁺) are needed for each sulfate ion (SO₄²⁻), resulting in the formula K₂SO₄.
Explanation:
- Potassium has an atomic number of 19 and is in Group 1 of the periodic table, which means it typically forms ions with a +1 charge.
- Sulfate is a polyatomic ion with the formula SO₄²⁻, where sulfur (S) is bonded to four oxygen (O) atoms. It carries a 2- charge.
- The charges on the potassium and sulfate ions must balance. Since potassium has a +1 charge, two potassium ions are needed to balance the 2- charge of the sulfate ion, leading to the formula K₂SO₄.
(b) Sulfur Hexafluoride (SF₆)
Sulfur hexafluoride is a chemical compound made up of sulfur (S) and fluorine (F). In this molecule, sulfur forms six bonds with fluorine atoms, resulting in the formula SF₆. Fluorine is a halogen with a 1- charge, so six fluorine atoms (F⁻) are required to balance the charge of sulfur, which has a neutral charge in this compound.
Explanation:
- Sulfur is in Group 16 of the periodic table and has a valence of 6, meaning it can form six bonds.
- Fluorine, also in Group 17, is highly electronegative and typically forms a 1- ion.
- Each fluorine atom forms a single bond with sulfur, and since sulfur can form up to six bonds, the compound SF₆ is stable, with six fluorine atoms bonded to one sulfur atom.
(c) Iron(III) Oxide (Fe₂O₃)
Iron(III) oxide, also known as ferric oxide, is a compound consisting of iron (Fe) and oxygen (O). The Roman numeral III in the name indicates that iron has a +3 charge in this compound. Oxygen, on the other hand, typically has a -2 charge. To balance the charges, two iron ions (Fe³⁺) are needed for every three oxide ions (O²⁻), which gives the formula Fe₂O₃.
Explanation:
- Iron can have multiple oxidation states, and in Iron(III) oxide, it has a +3 charge. This is indicated by the Roman numeral III.
- Oxygen typically forms O²⁻ ions, with a charge of -2.
- To balance the charges, two Fe³⁺ ions (totaling +6) are needed to combine with three O²⁻ ions (totaling -6), resulting in the formula Fe₂O₃.
In summary:
- Potassium sulfate: K₂SO₄
- Sulfur hexafluoride: SF₆
- Iron(III) oxide: Fe₂O₃