Part 1: Test of Melting Point
Generally, ionic solids have very high melting point temperatures. Covalent molecules have a lower melting point. Polar covalent molecules have a higher melting point than non-polar covalent molecules.
1. Mold an aluminum foil boat that will serve as a tray for the table salt, sugar, wax.
2. At different corners of the boat place a very small amount of each substance.
a. Table Salt
b. Sugar
c. Wax
3. Set the hot plate on high.
4. Observe and record the order of melting of the solids in your data table (1, 2, 3)
5. After observations are complete, CAREFULLY remove the aluminum foil boat with crucible tongs and allow it to cool completely. Dispose of the boat in the garbage.
conclusion:
Melting points and …show more content…
This energy is transferred to the cations and anions making them vibrate faster eventually breaking the ionic bonds between the cations and anions causing them to break free from the ionic lattice and enter the solution! See diagram below. Note the ions breaking away from the lattice!
However, not all ionic compounds are soluble in water. This is because in certain cases, the energy released from the ion-dipole interactions is insufficient to break the strong ionic bonds between the cations and anions
Covalent bonds do not dissolve in water, but some covalent compounds do.
When an ionic compound like NaCl dissolves in water, we end up with Na⁺ ions and Cl⁻ ions in solution.
This is a dissolving process, because the original compound contained the same ions.
When a covalent compound like HCl dissolves in water, we end up with H₃O⁺ ions and Cl⁻ ions in solution.
Although the covalent H-Cl bond breaks, this is a reaction process in which the products are soluble.
It is not a solution process, because the particles in solution are different from those in the original solute.
Covalent molecules attract each other by various intermolecular forces. These include H-bonds, dipole-dipole forces, and London dispersion …show more content…
A polar solute may attract the water molecules as strongly as the water molecules attract each other.
It should contain a highly electronegative atom such as N or O or, even better, an N-H or an O-H bond, because they can form H-bonds to the water molecules.
It will then be able to work its way among the water molecules (dissolve).
Sugar and ethanol are covalent compounds that are soluble in water, because they contain O-H groups that can H-bond to the water.
Nonpolar compounds like hydrocarbons have weak intermolecular attractive forces.
For example, hexane, C₆H₁₄, does not dissolve in water. Its molecules have little attraction to each other or to the water molecules.
The water molecules strongly attract each other. They stick together and keep out most of the hexane
Generally, ionic solids have very high melting point temperatures. Covalent molecules have a lower melting point. Polar covalent molecules have a higher melting point than non-polar covalent molecules.
1. Mold an aluminum foil boat that will serve as a tray for the table salt, sugar, wax.
2. At different corners of the boat place a very small amount of each substance.
a. Table Salt
b. Sugar
c. Wax
3. Set the hot plate on high.
4. Observe and record the order of melting of the solids in your data table (1, 2, 3)
5. After observations are complete, CAREFULLY remove the aluminum foil boat with crucible tongs and allow it to cool completely. Dispose of the boat in the garbage.
conclusion:
Melting points and …show more content…
This energy is transferred to the cations and anions making them vibrate faster eventually breaking the ionic bonds between the cations and anions causing them to break free from the ionic lattice and enter the solution! See diagram below. Note the ions breaking away from the lattice!
However, not all ionic compounds are soluble in water. This is because in certain cases, the energy released from the ion-dipole interactions is insufficient to break the strong ionic bonds between the cations and anions
Covalent bonds do not dissolve in water, but some covalent compounds do.
When an ionic compound like NaCl dissolves in water, we end up with Na⁺ ions and Cl⁻ ions in solution.
This is a dissolving process, because the original compound contained the same ions.
When a covalent compound like HCl dissolves in water, we end up with H₃O⁺ ions and Cl⁻ ions in solution.
Although the covalent H-Cl bond breaks, this is a reaction process in which the products are soluble.
It is not a solution process, because the particles in solution are different from those in the original solute.
Covalent molecules attract each other by various intermolecular forces. These include H-bonds, dipole-dipole forces, and London dispersion …show more content…
A polar solute may attract the water molecules as strongly as the water molecules attract each other.
It should contain a highly electronegative atom such as N or O or, even better, an N-H or an O-H bond, because they can form H-bonds to the water molecules.
It will then be able to work its way among the water molecules (dissolve).
Sugar and ethanol are covalent compounds that are soluble in water, because they contain O-H groups that can H-bond to the water.
Nonpolar compounds like hydrocarbons have weak intermolecular attractive forces.
For example, hexane, C₆H₁₄, does not dissolve in water. Its molecules have little attraction to each other or to the water molecules.
The water molecules strongly attract each other. They stick together and keep out most of the hexane