Question

Give the formulas of the compounds in each set: (a) Lead(II) oxide and lead(IV) oxide (b) Lithium nitride, lithium nitrite, and lithium nitrate (c) Strontium hydride and strontium hydroxide (d) Magnesium oxide and manganese(II) oxide

Short answer

Lead(II) oxide: \( \text{PbO} \), Lead(IV) oxide: \( \text{PbO}_2 \). Lithium nitride: \( \text{Li}_3\text{N} \), Lithium nitrite: \( \text{LiNO}_2 \), Lithium nitrate: \( \text{LiNO}_3 \). Strontium hydride: \( \text{SrH}_2 \), Strontium hydroxide: \( \text{Sr(OH)}_2 \). Magnesium oxide: \( \text{MgO} \), Manganese(II) oxide: \( \text{MnO} \).

Step-by-step solution

Understand the problem

Identify the chemical compounds given in the problem for each set and find their chemical formulas.

Identify the elements and their oxidation states

Determine the elements involved in each compound and their respective oxidation states.

Write the formulas for Set (a)

Lead can have the oxidation state of +2 or +4. The formula for Lead(II) oxide is \( \text{PbO} \) and for Lead(IV) oxide is \( \text{PbO}_2 \).

Write the formulas for Set (b)

Lithium has an oxidation state of +1. The formulas are:\( \text{Li}_3\text{N} \) for Lithium nitride (combining Lithium and Nitrogen), \( \text{LiNO}_2 \) for Lithium nitrite (combining Lithium and the Nitrite ion, \( \text{NO}_2^- \)), \( \text{LiNO}_3 \) for Lithium nitrate (combining Lithium and the Nitrate ion, \( \text{NO}_3^- \)).

Write the formulas for Set (c)

Strontium has an oxidation state of +2. The formulas are:\( \text{SrH}_2 \) for Strontium hydride (combining Strontium and Hydrogen), \( \text{Sr(OH)}_2 \) for Strontium hydroxide (combining Strontium and the Hydroxide ion, \( \text{OH}^- \)).

Write the formulas for Set (d)

Magnesium has an oxidation state of +2. The formula for Magnesium oxide is \( \text{MgO} \). Manganese can have an oxidation state of +2. The formula for Manganese(II) oxide is \( \text{MnO} \).

Key concepts

Oxidation States

Oxidation states, also known as oxidation numbers, are used to keep track of electron transfer in chemical reactions. These values represent the degree of oxidation of an atom in a compound. For example, in lead(II) oxide, the oxidation state of lead is +2, denoted as Pb(II). In lead(IV) oxide, the oxidation state is +4, shown as Pb(IV). Understanding oxidation states helps in determining the correct formula of a compound. For instance, lithium always has an oxidation state of +1 in compounds, leading to the formation of compounds like lithium nitride (Li3N), lithium nitrite (LiNO2), and lithium nitrate (LiNO3). Identifying and understanding oxidation states is a crucial step in writing and balancing chemical equations.

Chemical Nomenclature

Chemical nomenclature is the methodical naming of chemical compounds. There are rules established by IUPAC (International Union of Pure and Applied Chemistry) for naming compounds. For example, 'Lead(II) oxide' signifies a lead ion with a +2 charge combined with an oxide ion (O2-), resulting in the formula PbO. Similarly, 'Strontium hydride' (SrH2) indicates a compound made of strontium ions (Sr2+) and hydride ions (H-). Properly naming compounds ensures clear communication among scientists and helps in understanding the compound's composition and properties. For transition metals that have multiple possible oxidation states, Roman numerals in parentheses indicate the specific oxidation state of the metal, such as Manganese(II) oxide (MnO).

Compound Formulas

Chemical formulas represent the types and numbers of atoms in a molecule. They provide essential information about the composition of the compound. For instance, lead(II) oxide has a formula of PbO, showing one lead atom and one oxygen atom combining in a 1:1 ratio. In contrast, lead(IV) oxide's formula is PbO2, indicating one lead atom is combined with two oxygen atoms. Writing these formulas correctly requires knowledge of oxidation states and the ability to balance the charges. The formula for lithium nitrate is LiNO3, where one lithium ion (Li+) pairs with one nitrate ion (NO3-). Similarly, magnesium oxide (MgO) and manganese(II) oxide (MnO) illustrate simple, balanced expressions of elements and their combined states.

Transition Metals

Transition metals are elements found in groups 3-12 of the periodic table. They are notable for their ability to form multiple oxidation states and colorful compounds. For example, manganese can exhibit multiple oxidation states, including +2, +3, +4, +6, and +7, but in manganese(II) oxide, it has an oxidation state of +2, leading to the formula MnO. Transition metals often form complex ions and colored compounds, such as the bright colors observed in solutions of chromium or copper ions. These metals are also less reactive than alkali and alkaline earth metals, but they are crucial in many industrial and biological processes. Understanding transition metals' chemistry is essential in fields ranging from materials science to biochemistry.