Phase Diagram
Heating Curve
States of Matter, etc.
Intermolecular Forces
Types of Solids
100
What letter is the triple point?
E
100
What state is this substance at line E?
gas
100
What state of matter has the strongest intermolecular forces?
Solids
100
What are the three types of intermolecular forces in order from strongest to weakest?
Hydrogen bonds, Dipole-Dipole interactions, London Dispersion forces
100
What type of solid is composed of metal and nonmetal atoms that form a lattice of alternating positive and negative ions held together by ionic bonds? What type of force must be overcome to melt this solid?
Ionic solids. ionic bonds
200
What phase is the substance at point A?
solid
200
What is happening at line B?
The substance is freezing or melting. It is in a mixed solid/liquid state.
200
Describe the particles movement in the three states of matter.
Solid: vibrate in place
Liquid: Farther apart and can slide past one another
Gas: Farthest apart, high energy, moving quickly.
200
What type of force must be broken when water boils?
Hydrogen bonds
200
If two covalently bonded atoms are identical, the bond must be (polar covalent, nonpolar covalent, ionic, or network covalent).
nonpolar covalent, same atoms have no difference in electronegativity.
300
What is the normal boiling point of this substance?
350 C
300
What formula should be used to calculate the amount of energy used at line D?
q=mΔHvap
300
What happens to the boiling point of a liquid if the atmospheric pressure increases?
Boiling point increases. This is a direct relationship
300
Which has the weakest intermolecular forces?
3, this is a non-polar molecule, which only contain dispersion forces.
1 is polar and has dipole-dipole forces.
2 is polar and has H-bonding.
300
What type of solid is composed of nonmetal atoms that are held together with intermolecular forces?
molecular covalent solids
400
What phase transition occurs if you go from 0.75 atm to 1.25 atm at 300 C?
gas to liquid = condensation
400
How many steps would the following problem be: How much energy is used to convert 10 grams of chloroform from -40 C to 70 C?
3 steps, one for C, D and E
400
What is the difference between boiling and evaporation?
In boiling, the heat source causes liquid to turn into gas bubbles starting at the bottom and throughout the liquid.
In evaporation, the heat source causes surface liquid to escape as gas.
400
Which has the strongest intermolecular forces?
3. has H-bonding, the strongest intermolecular force which needs to be overcome in order to boil this substance.
2. has dipole-dipole forces
1. has LDFs
400
What type of solid is composed of nonmetal atoms that form a lattice held together with covalent bonds? Which forces must be overcome to melt this type of solid?
Network covalent solid, covalent bonds.
500
What phase transition occurs if you go from 0.5 atm at 100 C to -200 C?
gas to solid= deposition
500
Calculate the total amount of energy it takes to convert 10.0 g of water from -2.0 C to 105 C. (cs: 2.108 J/gC, Hfus: 334 J/g, cl: 4.184 J/gC, Hvap: 2330 J/g, cg: 1.996 J/gC)
qtotal=30,965.96= 31,000 J
1. q=(10)(2.108)(0-(-2))=42.16 J
2. q=(10)(334)=3340 J
3.q=(10)(4.184)(100-0)=4184 J
4. q=(10)(2330)=23300 J
5. q=(10)(1.996)(105-100)=99.8 J
500
NaCl is a solid at room temperature while water is liquid at room temperature, which has a lower enthalpy of fusion?
Water, it has weaker intermolecular forces which allow it to be in liquid form at room temperature.
NaCl has strong intermolecular forces which hold it together as a solid at room temperature.
500
Put these structures in order from strongest to weakest intra/intermolecular forces.
3. MgCl2 has ionic bonds, this is stronger than the dipole dipole forces in 1 and the LDFs in 2. This means it takes more energy to break the ionic bonds to melt the solid=highest heat of fusion.
500
Which atom would the dipole point towards in a molecule of H-Cl?
Chlorine, it is more electronegative.