What is the formula for ammonium sulfate?
To find the chemical formula for ammonium sulfate, we must first identify the constituent ions and their charges. Ammonium is a polyatomic ion represented by the chemical formula \(NH_4^+\), which carries a charge of \(+1\). Sulfate is another polyatomic ion represented by the chemical formula \(SO_4^{2-}\), which carries a charge of \(-2\).
Ionic compounds are electrically neutral, meaning the total positive charge must equal the total negative charge. To balance the \(-2\) charge of one sulfate ion, we need two ammonium ions, each with a \(+1\) charge. This gives a total positive charge of \(2 \times (+1) = +2\), which perfectly offsets the \(-2\) charge of the sulfate ion.
Based on the required stoichiometry of two ammonium ions for every one sulfate ion, the chemical formula is constructed by writing the symbol for the ammonium ion in parentheses followed by the subscript 2, and then writing the formula for the sulfate ion. Thus, the formula is \((NH_4)_2SO_4\). Comparing this result with the given options, we identify the correct formula as \((NH_4)_2SO_4\).
In daily life, chemical formulas help us understand the composition of substances we use. For example, ammonium sulfate is frequently used as a component in fertilizers to provide nitrogen and sulfur to plants. Knowing the correct chemical formula allows chemists and agriculturalists to calculate exact concentrations and ensure safety when handling these materials. Understanding ionic bonding and charge balancing is essential for everything from mixing household cleaning supplies safely to advanced laboratory research.