Give the chemical formula for each of the following ionic compounds: (e) cobalt(II) hydrogen carbonate (f) chromium(III) acetate (g) potassium dichromate.

Verified step by step guidance

1. Identify the ions involved in potassium dichromate: Potassium (K^+) and dichromate (Cr_2O_7^{2-}).
2. Determine the charges of each ion: Potassium has a charge of +1, and dichromate has a charge of -2.
3. Balance the charges to ensure the compound is neutral: You need two potassium ions to balance the charge of one dichromate ion.
4. Write the chemical formula by combining the ions in the correct ratio: K_2Cr_2O_7.
5. Verify the formula: Ensure the total positive charge (+2 from 2 K^+) balances the total negative charge (-2 from Cr_2O_7^{2-}).

Key Concepts

Ionic Compounds

Ionic compounds are formed when atoms transfer electrons, resulting in the formation of positively charged cations and negatively charged anions. These oppositely charged ions attract each other, creating a stable compound. Understanding the nature of ionic bonds is essential for determining the chemical formula of compounds like potassium dichromate.

Polyatomic Ions

Polyatomic ions are ions that consist of two or more atoms bonded together, carrying a net charge. In the case of potassium dichromate, the dichromate ion (Cr2O7^2-) is a polyatomic ion that plays a crucial role in the compound's formula. Recognizing these ions is vital for correctly writing the chemical formula of ionic compounds.

Chemical Formula Representation

A chemical formula represents the types and numbers of atoms in a compound. For ionic compounds, the formula reflects the ratio of cations to anions that balance the overall charge. In potassium dichromate, the formula K2Cr2O7 indicates that two potassium ions balance the charge of one dichromate ion, illustrating the principles of charge neutrality in ionic compounds.