Question

The names and chemical formulae of some chemical compounds are written in the first two columns of the table below. Each compound is soluble in water.
Imagine that a few tenths of a mole of each compound is dissolved in a liter of water. Then, write down in the third column of the table the chemical formula of the major chemical species that will be present in this solution. For example, you know water itself will be present, so you can begin each list with the chemical formula for water ().
Note: "major" chemical species are those present in concentrations greater than .
Compound Formula major species present when dissolved in water
Fructose C6H12O6 ¬______________________
Potassium Cyanide KCN ______________________
iron (II) bromide FeBr2 _______________________

Answer 1

Fructose C6H12O6 ¬ $C6H12O6 = C6H12O6, H2O$
Potassium Cyanide KCN $KCN = K +, CN -, H2O$
iron (II) bromide FeBr2 $FeBr2 = Fe 2+, Br -, H2O$
According to the fact that froctose is a covalent molecule, even if the molecula dissolves - it still remains. What about the others molecules, they are ionic and soluble in water. And that's it :)

Answer 2

Answer:

Fructose                                 C6H12O6    $H_{2}O,C_{6} H_{12} O_{6}$

Potassium Cyanide                    KCN             $H_{2}O,K^{+}, CN^{-}$

iron (II) bromide                         FeBr2            $H_{2}O,Fe^{2+}, Br^{-}$

Explanation:

Dissolving fructose in water do not involve a chemical change, just physical, therefore there's no ion formation, the dissolution happens because of the formation of weak intermolecular forces between water and the sugar.

In the case of KCN and FeBr2 ionic bonds can broke causing the complete dissosiation in water forming a positive and a negative ion.

I hope you find this information useful and interesting! Good luck!