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okay guys. so tell me if the following is wrong, right.
2. Use your textbook as a reference to look up structural formulas for the solutes and solvent you used today. Can you explain any solubility trends based upon structure of these substances? How does this relate to the adage that like dissolves like?
Organic compounds such as naphthalene and benzoic acid will not dissolve water because the molecular structures of these compounds is such that they are hydrophobic and nonpolar; for a substance to dissolve in water, it must be able to form similar interactions with the water molecules. This is not possible, however, given that water molecules are polar and hydrophilic. Incidentally, the water molecules do not have enough energy to break apart the hydrogen bonds in the naphthalene and benzoic acid; in which case, a homogenous solution will not form. On the other hand, ionic compounds are also polar; when placed in water, there will be ion-dipole interactions between the hydrogen end of the water molecule and the negative ion, and between the oxygen end of the water molecule and the positive ion.
Oh yeah, and tell me if this right?
Furthermore, it is not always possible to tell, on the basis of mere observation, what types of bonds the molecule possesses. For example, a water soluble substance may be either ionic or polar, but only a strong electrolyte will dissociate into its constituent ions. Using a circuit tester, one could differentiate between a semi-metal (poor conducter of electricity) & a metal (ionic, strong electrolyte).
2. Use your textbook as a reference to look up structural formulas for the solutes and solvent you used today. Can you explain any solubility trends based upon structure of these substances? How does this relate to the adage that like dissolves like?
Organic compounds such as naphthalene and benzoic acid will not dissolve water because the molecular structures of these compounds is such that they are hydrophobic and nonpolar; for a substance to dissolve in water, it must be able to form similar interactions with the water molecules. This is not possible, however, given that water molecules are polar and hydrophilic. Incidentally, the water molecules do not have enough energy to break apart the hydrogen bonds in the naphthalene and benzoic acid; in which case, a homogenous solution will not form. On the other hand, ionic compounds are also polar; when placed in water, there will be ion-dipole interactions between the hydrogen end of the water molecule and the negative ion, and between the oxygen end of the water molecule and the positive ion.
Oh yeah, and tell me if this right?
Furthermore, it is not always possible to tell, on the basis of mere observation, what types of bonds the molecule possesses. For example, a water soluble substance may be either ionic or polar, but only a strong electrolyte will dissociate into its constituent ions. Using a circuit tester, one could differentiate between a semi-metal (poor conducter of electricity) & a metal (ionic, strong electrolyte).