Write balanced equation for the combination of zinc and iodine to form Zinc iodide ZnI2; Phase symbols are not graded. Balanced equation: Zn + I2 -> ZnI2 How many moles of zinc are required to react with four moles of iodine? Answer: 4 moles of zinc.
The Correct Answer and Explanation is:
Balanced Equation:Zn+I2→ZnI2\text{Zn} + \text{I}_2 \rightarrow \text{ZnI}_2Zn+I2→ZnI2
Answer: 4 moles of zinc
Explanation:
In this chemical reaction, zinc (Zn) reacts with iodine (I₂) to form zinc iodide (ZnI₂). This is a type of synthesis or combination reaction, where two elements combine to form a single compound. The balanced chemical equation shows that one mole of zinc reacts with one mole of iodine molecules (I₂) to produce one mole of zinc iodide.
The formula ZnI₂ indicates that each molecule of zinc iodide contains one zinc atom and two iodine atoms. Since iodine naturally exists as diatomic molecules (I₂), a single I₂ molecule contains two iodine atoms, which matches the two iodine atoms in one formula unit of ZnI₂. Therefore, the reaction already reflects the correct stoichiometry and is balanced as written.
To determine how many moles of zinc are required to react with four moles of iodine (I₂), stoichiometry from the balanced equation is applied. The equation shows a 1:1 molar ratio between zinc and iodine molecules. This means that one mole of zinc is needed to fully react with one mole of iodine molecules.
Given four moles of iodine, the same number of moles of zinc is needed—four moles—to ensure a complete reaction without any limiting reagent left over.
Thus, to completely react with 4 moles of iodine (I₂), exactly 4 moles of zinc are required. This calculation ensures that all reactants are fully converted into the product, zinc iodide, without any excess zinc or iodine remaining unreacted.
