Question

Give the symbol, including the correct charge, for each of the following ions: (a) permanganate ion (b) nitrite ion (c) dihydrogen phosphate ion (d) ammonium ion (e) phosphate ion (f) sulfite ion

Short answer

(a) \( \text{MnO}_4^- \), (b) \( \text{NO}_2^- \), (c) \( \text{H}_2\text{PO}_4^- \), (d) \( \text{NH}_4^+ \), (e) \( \text{PO}_4^{3-} \), (f) \( \text{SO}_3^{2-} \)

Step-by-step solution

Identify the Permanganate Ion

The permanganate ion is known in chemistry as a compound containing manganese in a specific oxidation state. The symbol for the permanganate ion is written as \( \text{MnO}_4^- \). It has a charge of -1.

Identify the Nitrite Ion

The nitrite ion consists of nitrogen and oxygen in a specific arrangement. The symbol for the nitrite ion is \( \text{NO}_2^- \), with a charge of -1.

Identify the Dihydrogen Phosphate Ion

The dihydrogen phosphate ion has hydrogen atoms combined with a phosphate group. The correct symbol is \( \text{H}_2\text{PO}_4^- \) and carries a charge of -1.

Identify the Ammonium Ion

Commonly found in many chemical reactions, the ammonium ion is one of the few positively charged ions listed. It is represented as \( \text{NH}_4^+ \), with a charge of +1.

Identify the Phosphate Ion

The phosphate ion is derived from phosphoric acid, releasing all hydrogen ions in the reaction. It is represented by \( \text{PO}_4^{3-} \) and carries a charge of -3.

Identify the Sulfite Ion

The sulfite ion is a result of the reduction of sulfur in sulfurous acid. It is denoted as \( \text{SO}_3^{2-} \), with a charge of -2.

Key concepts

Oxidation State

The oxidation state is an essential concept in chemistry.It helps indicate the degree of electron deficiency or excess in an atom.In ions, this becomes crucial to understand their behavior in reactions. Generally, the oxidation state reflects the charge of the ion. For example, in the permanganate ion (\[\text{MnO}_4^-\]), manganese has an oxidation state of +7.This means that manganese has lost 7 electrons compared to its neutral state. Understanding oxidation states assists in predicting how an ion will combine with others and form compounds. In the sulfite ion (\[\text{SO}_3^{2-}\]), sulfur has an oxidation number of +4, which informs us about its electron arrangement in bonding.

Chemical Formulas

Chemical formulas are like blueprints of chemical species.They convey the type and number of each atom present in a molecule or ion. For ions, these formulas also help represent the charge associated with them. For instance, the formula for the ammonium ion is \[\text{NH}_4^+\]. This tells us that it consists of one nitrogen atom covalently bonded to four hydrogen atoms and carries a positive charge.In contrast, the formula for phosphate ion is \[\text{PO}_4^{3-}\], indicating the presence of one phosphorus atom surrounded by four oxygen atoms, bearing a charge of -3. A solid grasp on writing and interpreting these chemical formulas aids in comprehending molecular composition and reactions.

Ionic Charges

Ionic charges provide vital insights into chemical species.The charge of an ion is a result of the loss or gain of electrons. A positive charge indicates fewer electrons than protons, seen in cations like the ammonium ion (\[\text{NH}_4^+\]). Conversely, a negative charge signifies more electrons than protons, exemplified by anions such as the nitrite ion (\[\text{NO}_2^-\]). These charges are crucial for understanding chemical interactions. They dictate how ions combine to form salts and other compounds. The attraction between positive and negative charges in ions is what leads to ionic bonding. Handler rates these attractions and predicts the formation of new compounds.

Ions Identification

Identifying ions is a fundamental skill in chemistrystudents should master. This involves recognizing the specific composition and charge of an ion. Common practices include memorizing particular ions' names, formulas, and corresponding charges. For example, the dihydrogen phosphate ion is noted as \[\text{H}_2\text{PO}_4^-\] and carries a charge of -1.Understanding its structure reveals two hydrogen atoms linked to the phosphate base. Recognizing ions also involves familiarizing oneself with common ions encountered in chemistry labs. By doing so, students can easily identify ions in reactions, helping them predict outcomes. Identification of ions like the sulfate and sulfite (\[\text{SO}_3^{2-}\]) ions also reveals important insights into their chemical nature and usage.