The chemical formula K2SO4 represents-
Potassium sulphate
Identifying Chemical Formulas: K₂SO₄
Understanding chemical formulas is fundamental in chemistry. A chemical formula represents the composition of a compound, showing the types of atoms and their ratio. The formula K₂SO₄ tells us which elements are present and how many atoms of each are combined in one formula unit of the substance.
Breaking Down the Formula K₂SO₄
Let's look closely at the chemical formula K₂SO₄:
- K represents the element Potassium. The subscript ₂ indicates there are two potassium atoms or ions.
- S represents the element Sulfur.
- O represents the element Oxygen. The subscript ₄ indicates there are four oxygen atoms.
In ionic compounds, K₂SO₄ is formed from positive ions (cations) and negative ions (anions). Potassium (K) is an alkali metal and forms a +1 ion, K⁺. The group of atoms SO₄ is a polyatomic ion called sulfate, which has a charge of -2, SO₄²⁻. To balance the charges, two K⁺ ions are needed for every one SO₄²⁻ ion, resulting in the neutral compound K₂SO₄.
Thus, the compound is formed from Potassium ions and Sulfate ions.
Naming Ionic Compounds with Polyatomic Ions
The general rule for naming ionic compounds formed from a metal and a polyatomic ion is to name the metal first, followed by the name of the polyatomic ion. In K₂SO₄:
- The metal is Potassium.
- The polyatomic ion is Sulfate (SO₄²⁻).
Combining these names gives Potassium sulfate.
Evaluating the Options
Now let's look at the given options and their corresponding chemical formulas:
| Compound Name | Chemical Formula |
|---|---|
| Potassium sulphate | K₂SO₄ |
| Potassium chloride | KCl |
| Potassium nitrate | KNO₃ |
| Aluminium sulphate | Al₂(SO₄)₃ |
Comparing the formula K₂SO₄ with the formulas in the table, we can see that K₂SO₄ represents Potassium sulphate.
Conclusion on K₂SO₄ Formula
Based on the composition and standard chemical nomenclature rules, the chemical formula K₂SO₄ represents the compound Potassium sulphate.
Revision Table: Chemical Formulas and Names
| Formula | Cation | Anion | Compound Name |
|---|---|---|---|
| K₂SO₄ | K⁺ (Potassium ion) | SO₄²⁻ (Sulfate ion) | Potassium sulphate |
| KCl | K⁺ (Potassium ion) | Cl⁻ (Chloride ion) | Potassium chloride |
| KNO₃ | K⁺ (Potassium ion) | NO₃⁻ (Nitrate ion) | Potassium nitrate |
| Al₂(SO₄)₃ | Al³⁺ (Aluminium ion) | SO₄²⁻ (Sulfate ion) | Aluminium sulphate |
Additional Information: Polyatomic Ions in Chemistry
Polyatomic ions are ions composed of two or more atoms covalently bonded together, carrying a net positive or negative charge. Learning common polyatomic ions is crucial for naming and writing formulas for many chemical compounds.
Some common polyatomic ions include:
- Sulfate ion: SO₄²⁻
- Nitrate ion: NO₃⁻
- Hydroxide ion: OH⁻
- Carbonate ion: CO₃²⁻
- Ammonium ion: NH₄⁺
- Phosphate ion: PO₄³⁻
When writing formulas with polyatomic ions, parentheses are used if there is more than one polyatomic ion unit needed to balance the charges, as seen in Aluminium sulphate, Al₂(SO₄)₃.
Important Questions from Chemical Bond and Molecular Structure
- Which one of the following is a covalent compound?
Which one of the following is the correct molecular formula of ammonium carbonate if the valency of ammonium ion is (+1) and carbonate anion is (-2)?
Which one of the following statements is correct?
Which one of the following is the chemical formula of gypsum?
Which one of the following statements about water is not true ?
