What is the formula for the compound formed between calcium and each of the following polyatomic ions? a. hydroxide b. chromate c. phosphate d. cyanide

Name: Chemistry: A Molecular Approach
Author: Tro
ISBN: 9780134112831

검증된 단계별 안내

insert step 1> Identify the charge of the calcium ion (Ca). Calcium is in group 2 of the periodic table, so it forms a Ca^{2+} ion.

insert step 2> Determine the charge of each polyatomic ion: hydroxide (OH^{-}), chromate (CrO_4^{2-}), phosphate (PO_4^{3-}), and cyanide (CN^{-}).

insert step 3> For each compound, balance the total positive and negative charges to ensure the compound is neutral.

insert step 4> Write the chemical formula for each compound by combining the calcium ion with the appropriate number of each polyatomic ion to achieve charge neutrality.

insert step 5> Review the formulas to ensure they reflect the correct stoichiometry based on the charges of the ions involved.

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Ionic Compounds

Ionic compounds are formed when metals react with nonmetals, resulting in the transfer of electrons. In this case, calcium, a metal, will lose two electrons to form a Ca²⁺ ion, while polyatomic ions, which are groups of atoms with a net charge, will gain or share electrons to achieve stability. The resulting compound is electrically neutral, meaning the total positive charge from the calcium ions must balance the total negative charge from the polyatomic ions.

Polyatomic Ions

Polyatomic ions are ions composed of two or more atoms covalently bonded together, carrying a net charge. Examples include hydroxide (OH⁻), chromate (CrO₄²⁻), phosphate (PO₄³⁻), and cyanide (CN⁻). Understanding the charge and composition of these ions is crucial for determining the correct formula of the resulting ionic compound when combined with calcium.

Chemical Formula Writing

Writing chemical formulas involves combining the symbols of the elements or ions involved, along with their respective charges, to reflect the composition of the compound. The subscripts in the formula indicate the number of each type of ion needed to achieve electrical neutrality. For example, when combining calcium with a polyatomic ion, the ratio of calcium ions to polyatomic ions must be adjusted based on their charges to ensure the overall charge of the compound is zero.