Write formulas for the following binary compounds: (a) Potassium chloride (b) Tin(II) bromide (c) Calcium oxide (d) Barium chloride (e) Aluminum hydride

Verified step by step guidance

1. Identify the symbols for the elements involved in each compound. Potassium (K), Chlorine (Cl), Tin (Sn), Bromine (Br), Calcium (Ca), Oxygen (O), Barium (Ba), Aluminum (Al), and Hydrogen (H).
2. Determine the valency or oxidation state for each element. Potassium, Calcium, Barium, and Aluminum generally form +1, +2, +2, and +3 ions respectively. Chlorine, Bromine, and Oxygen generally form -1, -1, and -2 ions respectively. Tin(II) indicates Tin with a +2 charge.
3. Write the formula by balancing the charges of the cations and anions so that the total charge of the compound is zero. Use subscripts to indicate the number of each ion needed to balance the charges.
4. For compounds with transition metals like Tin(II), use the Roman numeral to determine the charge of the metal cation. Tin(II) means Tin has a +2 charge.
5. Combine the ions: Potassium and Chlorine form Potassium chloride (KCl), Tin(II) and Bromine form Tin(II) bromide (SnBr2), Calcium and Oxygen form Calcium oxide (CaO), Barium and Chlorine form Barium chloride (BaCl2), Aluminum and Hydrogen form Aluminum hydride (AlH3).

Key Concepts

Ionic Compounds

Ionic compounds are formed when metals transfer electrons to nonmetals, resulting in the formation of positively charged cations and negatively charged anions. The electrostatic attraction between these oppositely charged ions leads to the creation of a stable compound. Understanding the nature of ionic bonds is essential for writing the correct formulas for binary compounds.

Nomenclature of Binary Compounds

The nomenclature of binary compounds involves specific rules for naming and writing formulas based on the elements involved. For ionic compounds, the name of the metal (cation) is followed by the name of the nonmetal (anion) with its ending changed to '-ide.' Additionally, transition metals may require Roman numerals to indicate their oxidation states, as seen in compounds like tin(II) bromide.

Charge Balance in Compounds

In binary compounds, the total positive charge must balance the total negative charge to ensure electrical neutrality. This requires determining the oxidation states of the elements involved and using them to derive the correct ratio of ions in the formula. For example, in calcium oxide, calcium has a +2 charge and oxygen has a -2 charge, leading to the formula CaO.