Write the formulas of the principal molecular or ionic species present in an aqueous solution of each substance.
(a) Sodium Chloride, NaCl
(b) Hydrogen bromide, HBr
(c) Iron (III) sulfate, Fe2(SO4)3
(d) Ethanol, CH3CH2OH
(e) Glucose, C6H12O6
(f) Ammonium acetate, NH4CH3COO
Na^+ + Cl^-
H^+ + Br^-
Fe^+3 + SO4^-2
CH3CH2OH
C6H12O6
NH4^+ + CH3COO^-
To determine the formulas of the principal molecular or ionic species present in an aqueous solution of each substance, we need to consider the dissociation behavior of the compound in water.
(a) Sodium Chloride, NaCl:
Sodium chloride is an ionic compound. When it dissolves in water, it dissociates into its constituent ions: Na+ and Cl-. Therefore, in an aqueous solution, the principal species present are Na+ and Cl-.
(b) Hydrogen bromide, HBr:
Hydrogen bromide is a covalent compound that dissolves in water to form an acidic solution. In water, HBr dissociates into H+ and Br-. Therefore, in an aqueous solution, the principal species present are H+ and Br-.
(c) Iron (III) sulfate, Fe2(SO4)3:
Iron (III) sulfate is an ionic compound. When it dissolves in water, it dissociates into its constituent ions: Fe3+ and SO4(2-). Therefore, in an aqueous solution, the principal species present are Fe3+ and SO4(2-).
(d) Ethanol, CH3CH2OH:
Ethanol is a covalent compound that does not significantly dissociate in water. In an aqueous solution, the principal molecular species present is CH3CH2OH (ethanol) itself.
(e) Glucose, C6H12O6:
Glucose is a covalent compound, commonly known as a sugar. It does not dissociate in water, so in an aqueous solution, the principal molecular species present is C6H12O6 (glucose) itself.
(f) Ammonium acetate, NH4CH3COO:
Ammonium acetate is an ionic compound. When it dissolves in water, it dissociates into its constituent ions: NH4+ and CH3COO-. Therefore, in an aqueous solution, the principal species present are NH4+ and CH3COO-.