To determine the number of moles of ions produced by complete dissociation of one mole of Mohr's salt in water, we first need to understand its chemical composition and how it dissociates. Mohr's salt is a double salt with the chemical formula FeSO4⋅(NH4)2SO4⋅6H2O. When it dissociates completely in water, it produces ions from each of its constituent compounds. The dissociation can be represented as follows: FeSO4⋅(NH4)2SO4⋅6H2O⟶Fe2++SO42−+2NH4++SO42−+6H2O Let's break this down step by step: 1. One mole of FeSO4 produces: 1 mole of Fe2+ 1 mole of SO42− 2. One mole of (NH4)2SO4 produces: 2 moles of NH4+ 1 mole of SO42− Summing up all the ions produced, we get: 1 mole of Fe2+ 2 moles of SO42− 2 moles of NH4+ Therefore total number of moles of ions produced by complete dissociation of one mole of Mohr's salt are: 1+2+2=5 moles of ions Thus, the correct answer is: Option C: 5