In the balanced chemical equation for the reaction between ethylenediaminetetraacetic acid (EDTA) and calcium ion (Ca^{2+}), what is the mole ratio of EDTA to Ca^{2+}?

• A. 4:1
• B. 1:1
• C. 2:1
• D. 1:2

Answer: (B)

Verified step by step guidance

1. Identify the chemical species involved in the reaction: ethylenediaminetetraacetic acid (EDTA) and calcium ion (Ca^{2+}).
2. Recall that EDTA is a hexadentate ligand, meaning it can bind to a metal ion through six coordination sites, effectively wrapping around the metal ion.
3. Understand that in complexation reactions, one EDTA molecule typically binds to one metal ion to form a stable complex.
4. Write the balanced chemical equation for the complexation: \(\mathrm{Ca^{2+} + EDTA^{4-} \rightarrow [CaEDTA]^{2-}}\).
5. From the balanced equation, determine the mole ratio of EDTA to Ca^{2+} is 1:1, meaning one mole of EDTA reacts with one mole of calcium ion.