CHEM 1220

atm to mmHg

1 atm = 760 mmHg

simple cubic structure

1 atom per unit cell

What are the two criteria that favor spontaneous formation of a solution?

1. Decrease in the internal energy of the system (EXOTHERMIC change). 2. Increase dispersal of matter in the system (increase in ENTROPY).

What are the defining traits of a solution (5)?

1. Has the same composition at all of its points 2. The physical state of the solution is the same as that of the solvent 3. Dispersed on a molecular scale (solute particles surrounded by solvent species) 4. Will not settle out from the solvent 5. The concentrations of the components can vary.

kPa to atm

101.3

deci

10^-1

centi

10^-2

mili

10^-3

micro

10^-6

nano

10^-9

kilo

10^3

coordination face centered cubic

12

body centered cubic

2 atoms per unit cell

face centered cubic

4 atoms per unit cell

what is the percentage of atom volume in the unit cell Simple cubic?

52% is atoms 48% is empty space

coordination of simple cubic

6

percentage of volumee in body centered cubic?

68% atom

Face centered cubic volum percentage

74% atom

coordination of body centered cubic

8

R constants

8.314 J/k*mol 8.206 L*atm/k*mol

A colloid formed between two liquids is known as a(n) A) sol B) emulsion C) foam D) aerosol

A colloid formed between two liquids is known as an emulsion.

A colloid formed with gas particles dispersed in a liquid is known as a(n): A) aerosol B) emulsion C) foam D) sol E) gel

A colloid formed with gas particles dispersed in a liquid is known as a foam.

A colloid formed with liquid particles dispersed in a gas is known as a(n): A) aerosol B) emulsion C) foam D) sol E) gel

A colloid formed with liquid particles dispersed in a gas is known as an aerosol.

A colloid formed with liquid particles dispersed in a solid is known as a(n): A) aerosol B) emulsion C) foam D) sol E) gel

A colloid formed with liquid particles dispersed in a solid is known as a gel.

A colloid formed with solid particles dispersed in a gas is known as a(n): A) aerosol B) emulsion C) foam D) sol E) gel

A colloid formed with solid particles dispersed in a gas is known as an aerosol.

A colloid formed with solid particles dispersed in a liquid is known as a(n): A) aerosol B) emulsion C) foam D) sol E) gel

A colloid formed with solid particles dispersed in a liquid is known as a sol.

Which of the following describes a colloid? A) a mixture that separates upon standing, but can be remixed with stirring or shaking. B) a homogenous mixture made from very small particles. C) a homogenous mixture made from larger particles. D) A dispersion of large particles evenly distributed through a mixture.

A colloid is a dispersion of large particles that are evenly distributed through a mixture.

Which of the following is described by the following characteristics? a very hard, colorless substance melting at about 3000 °C A) BN B) P₄S₃ C) Pb D) CaCl₂ E) C₆H₁₂O₆

A high melting point is indicative of very strong intermolecular forces, meaning that this substance is not held together by dispersion forces like the molecular solid P₄S₃. Because this substance is colorless, it is not a metal like Pb (which is lustrous) or an ionic solid like CaCl₂ (which is white). The remaining option, BN, is a network solid, which meets all of the properties mentioned in the question: due to its strong network of covalent bonds, BN forms a very hard solid with a significantly high melting point.

Which of the compounds below is an example of a network solid? A) C₂₅H₂₅(s) B) NaCl(s) C) SiO₂(s) D) S₈(s) E) MgO(s)

A network solid is one in which all of the atoms are held together by a network of covalent bonds, with the subscripts in the molecular formula providing the ratio of atoms within the solid. Of these options, only SiO₂(s) is capable of forming a network solid, with each Si atom covalently bound to four O atoms. The other options are either held together by ionic bonds (NaCl and MgO) or by intermolecular forces (C₂₅H₂₅ and S₈).

What is the definition of boiling point with its relationship to vapor pressure?

A substance's normal boiling point is defined as the temperature at which its vapor pressure is equal to the external pressure. As such, all liquid substances at their normal boiling point will have the same vapor pressure, which is 1 atm at standard temperature and pressure.

Which of the following aqueous solutions would have the lowest vapor pressure? A) 0.15 M NaCl B) 0.10 M MgCl₂ C) 0.30 M CH₃OH D) 0.10 M Li₃PO₄

According to Raoult's Law, the vapor pressure of a solution is proportional to the mole fraction of solvent, and therefore, inversely proportional to the total solute concentration. So, the highest molarity of ions will have the lowest vapor pressure. Since ionic compounds dissociate in aqueous solution, Li₃PO₄ dissociates to 3 Li⁺ and 1 PO₄³⁻ ion for a total of 4 ions. Since the molarity of Li₃PO₄ was 0.10 M, the concentration of ions is 0.40 M. The other solutions all have total solute concentrations of 0.30 M.

Which of the following aqueous solutions would have the highest vapor pressure? A) 0.10 M NaCl B) 0.10 M MgCl₂ C) 0.10 M CH₃OH D) 0.10 M Li₃PO₄

According to Raoult's Law, the vapor pressure of a solution is proportional to the mole fraction of solvent, and therefore, inversely proportional to the total solute concentration. So, the lowest molarity of ions will have the highest vapor pressure. Since ionic compounds dissociate in aqueous solution and molecular compounds do not, the total concentration of ions is lowest in CH₃OH (0.10 M). The other solutions (all ionic) have total solute concentrations greater than 0.10M.

Which of the following solutes will lower the freezing point the most in 1 L H₂O? A) 1 mol NaI B) 1 mol KI C) 1 mol MgI₂ D) All would lower the freezing point equally

All of these compounds are soluble in water so they will all break up into ions. The more ions there are in solution, the bigger the change to the freezing point (and boiling point). Since MgI₂ will break up into one magnesium ion and two iodide ions, it will produce more ions in solution than the other two choices.

Which one of the following can be classified as a nonelectrolyte? A) LiIO₃ B) CI₂ C) NaI D) KIO E) HI

An electrolyte is a substance that can dissolve in water to form ions. CI₂ does not ionize in water because it is a covalent molecular compound.

Which of the following ions will contribute most to elevating the boiling point of H₂O? A) Na⁺ B) K⁺ C) Ca²⁺ D) Fe³⁺ E) All will contribute equally

Anything that is dissolved will elevate the boiling point (and lower the freezing point) of the solvent. The amount of solute, not the characteristics, increases the degree of change.

Body-centered cubic.

Body-centered cubic. This is a cubic unit cell with atoms on every corner of the unit cell and an atom in the center of the cell.

Which of the following best describes what takes place during the solvation process?

By an IUPAC definition, solvation is an interaction of a solute with the solvent, which leads to stabilization of the solute species in the solution. Therefore solvent molecules surround solute molecules and pull them out into the solution.

C to K

C + 273.15

Which of the following solutions would be most likely to show a positive deviation from Raoult's law? A) CH₃CH₂CH₂OH and CH₃CH₂OH B) CH₃CH₂CH₂CH₂CH₃ and CH₃CH₂CH₂CH₃ C) CH₃CH₂CH₂OCH₃ and CH₃CH₂CH₂CH₂OH D) CH₃CH₂NHCH₃ and CH₃CH₂CH₂NH₂

CH₃CH₂CH₂OCH₃ has only dipole and dispersion forces, while CH₃CH₂CH₂CH₂OH also has hydrogen bonding forces in addition. This pair has the biggest difference in forces than the other three pair, in which the forces are similar in both compounds. Therefore CH₃CH₂CH₂OCH₃ and CH₃CH₂CH₂CH₂OH is most likely to show a deviation from Raoult's law.

Which of the following substances has the highest melting point? A) NaCl B) Cl₂ C) NO₂ D) CH₄ E) H₂S

Compounds with high melting points have strong intermolecular forces, such as ion-ion forces. Of these options, NaCl is the only ionic solid, whereas the other options are held together by dipole-dipole forces (NO₂ and H₂S) or dispersion forces (Cl₂ and CH₄). Because NaCl has the strongest intermolecular forces, it will have the highest melting point.

Which of the following solids would be expected to display the highest melting point? A) NaCl B) SrBr₂ C) CBr₄ D) MgCl₂ E) C₁₂H₂₂O₁₁

Compounds with high melting points have strong intermolecular forces, such as ion-ion forces. Of these options, NaCl, SrBr₂, and MgCl₂ are ionic solids, whereas the other options are held together by weaker intermolecular forces such as dispersion forces and dipole-dipole forces. When comparing the strength of ion-ion forces among ionic solids, those that contain smaller ions with higher charges are held together more strongly. Both SrBr₂ and MgCl₂ have ions with a 2+ charge (whereas the ions in NaCl both have single charges), but the Mg and Cl are smaller ions than Sr and Br, respectively, as they are located closer to the top of the periodic table. As a result, MgCl₂ will have the strongest ion-ion intermolecular forces, and as such will exhibit the highest melting point.

Which of the following steps in solution formation is exothermic? A) overcoming the solute-solute intermolecular forces. B) overcoming the solvent-solute intermolecular forces. C) overcoming the solvent-solvent intermolecular forces. D) establishing the solute-solvent intermolecular forces.

D) establishing the solute-solvent intermolecular forces It takes energy to overcome any type of intermolecular forces, so overcoming intermolecular forces would be endothermic. Establishing forces such as those between solute and solvent, on the other hand, release energy and are exothermic.

If solute's electrostatic forces > solvation forces

Endothermic

What process is solute-solute?

Endothermic

What process is solvent-solvent?

Endothermic

If solvation forces > solute's electrostatic forces

Exothermic

What process is solute-solvent?

Exothermic

Face centered cubic.

Face centered cubic. This is a cubic unit cell with atoms on every corner of the unit cell and an atom on each face.

Covalent compounds cannot conduct electricity?

False

Soap suds would be an example of A) sol B) emulsion C) foam D) aerosol

Foams are created when gases are inside liquids or solids. Soap suds are gases that are inside liquids or solids.

Condensation

Gas to liquid

which law states the relation between solubility and partial pressure?

Henry's law

If the extracellular fluid outside the cell has a higher osmolarity than the cell's cytoplasm inside the cell, then it's said to be a _________ solution and the net flow of water will be ________. A) hypertonic, into the cell B) hypertonic, out of the cell. C) hypotonic, into the cell. D) hypotonic, out of the cell. E) isotonic, balanced with no movement in or out of the cell.

If the extracellular fluid outside the cell has a higher osmolarity than the cell's cytoplasm inside the cell, then it's said to be a hypertonic solution. The net flow of water will be out of the cell moving from the side with the lower concentration of solute towards the side with the higher concentration.

Which of the following properties is not typical of metallic solids? A) High coordination number of atoms in the lattice. B) High vapor pressure. C) High electrical conductivity. D) High thermal conductivity. E) All of the above are true statements.

Metallic solids are held together by metallic bonds, which are relatively strong. As a result, the metal atoms are unlikely to escape into the gaseous phase, meaning they will not have high vapor pressures.Compounds with high melting points have strong intermolecular forces, such as ion-ion forces. Of these options, NaCl, SrBr₂, and MgCl₂ are ionic solids, whereas the other options are held together by weaker intermolecular forces such as dispersion forces and dipole-dipole forces.

Which of the following statements is incorrect? A) Molecular solids typically have high melting points. B) The binding forces in a molecular solid include London dispersion forces. C) Ionic solids usually have high melting points. D) Ionic solids are insulators. E) All of these statements are correct.

Molecular solids are held together by dispersion forces, which are the weakest type of intermolecular force. As a result, the molecules in a molecular solid will not be held together tightly and can therefore melt at relatively low temperatures, meaning they will not have high melting points.

Which one of the following can be classified as a strong electrolyte? A) C₆H₁₂O₆ B) CH₃OH C) NH₄NO₃ D) HC₂H₃O₂ E) H₂O

NH₄NO₃ dissolves in water and completely dissociates into ammonium ions and nitrate ions. Therefore it is classified as a strong electrolyte.

Which of the following statements is true? A) When a nonvolatile solute is added to a solvent, the solute vapor pressure decreases. B) When a nonvolatile solute is added to a solution, the solvent vapor pressure increases. C) When a nonvolatile solute is added to a solvent, the solute vapor pressure increases. D) When a nonvolatile solute is added to a solution, the solvent vapor pressure decreases.

One driving force in the vaporization of a liquid is an increase in disorder (entropy). Gas molecules are more disordered than liquid molecules. Adding a non-volatile solute to a liquid also increases the disorder of the liquid molecules, so the difference in disorder between the liquid and gas phases is not as great as with a pure substance. Therefore the tendency to vaporize is not as great for the solution as it is for the pure liquid, resulting in a lower vapor pressure for the solution.

Which of the following statements is true? A) Osmotic pressure is the pressure from particles travelling through a membrane. B) Osmotic pressure is the pressure required to force solvent particles to pass through a membrane. C) Osmotic pressure is the pressure required to separate the solvent from the solute. D) Osmotic pressure is the pressure required to stop osmosis.

Osmosis is the process by which solvent particles pass through a semipermeable membrane from a dilute to a concentrated solution. Osmotic pressure is the pressure required to stop osmosis.

Solvent

Present in greater concentrations

Solute

Present in lesser concentration

which law states the relationship between the vapor pressures of solution and the concentrations of those components?

Raoult's law

Which one of the following is NOT a strong electrolyte? A) LiOH B) HNO₃ C) KBr D) NH₄Cl E) HNO₂

Strong electrolytes completely dissociate in water. They can be in the form of salts, strong acids, or strong bases. HNO₂ dissociates in water but not completely and is a weak acid. It is a weak electrolyte.

Electrolyte by definition

Substance that yield ions

Which term is a measure of the energy required to increase the surface area of a liquid?

Surface tension

Which one of the following aqueous solutions would have the highest freezing point? A) 1.0 m NaNO₃ B) 2.0 m CH₃OH C) 1.0 m C₆H₁₂O₆ D) 1.0 m CaCl₂

The dissolved solute will lower the freezing point. The more "things" that are dissolved (ions or molecules), the lower the freezing point will be. Since C₆H₁₂O₆ is a molecule, it will not break apart and there will only be a concentration of 1.0 m of molecules in solution. It will lower the freezing point less than all the other choices. There will be fewer "things" in solution and this will lower the freezing point less than the other choices.

Which of the following aqueous solutions would have the highest boiling point? A) 1.0 m NaNO₃ B) 1.0 m HF C) 1.0 m C₆H₁₂O₆ D) 1.0 m CaCl₂

The dissolved solute will raise the boiling point. The more "things" that are dissolved (ions or molecules), the higher the boiling point will be. The CaCl₂ will break up into one Ca²⁺ ion and two Cl⁻ ions and there will be a concentration of 3.0 m of "things" in solution. The other choices will have fewer "things" in solution and will raise the boiling point less.

A liquid typically boils at 200 °C. If an insoluble salt is added to the liquid, its new boiling point will be: A) Greater than 200 °C B) Less than 200 °C C) 200 °C D) Not enough info

The material must be dissolved in the solvent in order to elevate the boiling point or lower the freezing point. Since this salt is insoluble, it will not dissolve in the solvent.

How to tell when a solution is ideal based off of enthalpy

There is no change in enthalpy when the solution is formed, which indicates that the solute-solvent attractions are the same as the solute-solute and solvent-solvent attractions, so the solution is ideal.

Calculate the total number of atoms contained within this unit cell.

To calculate the number of atoms in the unit cell, multiply the number of atoms on vertices times the fraction of each atom that is within the unit cel

Any gas liquid or solid can act as a solvent true or false?

True

Which one of the following can be classified as a weak electrolyte? A) HBr B) CaF₂ C) OBr₂ D) HF E) F₂

Weak electrolytes ionize when dissolved in water but not completely. Weak acids and bases are weak electrolytes and HF is a weak acid. Therefore, HF is a weak electrolyte.

What does it mean when water is ionized?

When one molecule of water gives up a proton to another molecular of water

What is the characteristics of the intermolecular forces in an ideal solution?

When the intermolecular forces between solute and solvent are equal to its separated components

what is the relationship between the edge length and the radius (body cubic)?

X = (4/sqroot of 3)R

what is the relationship between the edge length and the radius (Face cubic)?

X = (sqroot of 8) R

what is the relationship between the edge length and the radius (simple cubic)?

X = 2R (Edge length is twice the value of the radius)

a lower vapor pressure means

a higher boiling point

what is the relationship between IMF and Vapor pressure?

a low IMF will have a high vapor pressure and a high IMF will have a low vapor pressure

why is molarity not used in colligative properties?

because the solution volumes vary with temperature causing the molar concentrations to also vary.

which is the most efficient use of space?

face centered cubic?

Deposition

gas to solid

boiling point elevation

in crease boiling point observed when nonvolatile solute is dissolved in a solvent. directly proportional to the molal concentration of solute species

Insulator vs. Conductor

insulator does not conduct electricity. conductors do

boiling point

is the temperature at which its vapor pressure is equal to ambient atmospheric pressure.

Solubility

maximum concentration that may be achieved under given conditions when the dissolution process is at equilibrium.

atom on the inside

only one atom (atom contributes fully to that unit cell)

equilibrium vapor pressure of a liquid

pressure exerted by its gaseous phase when vaporization. and condensation are occurring at equal rates

colligative properties

properties that depend on the concentration of solute particles but not on their identity

mole fraction

ratio of the molar amount to the total number of moles of all solution components

molality

ratio of the number of moles of solute to the mass of the solvent in kilograms

saturated, unsaturated, and supersaturated

saturated - equal to solubility unsaturated - under solubility supersaturated - over solubility

corner atom in a cube

shared between eight unit cells. (1/8 per each unit cell)

atom on the edge of a cube

shared by four unit cells (1/4 per unit cell)

atom on a face

shared by two unit cells (1/2 per each unit cell)

What is (primitive) cubic packing?

simple (primitive) cubic packing with atoms on each of the corners (vertices).

Sublimation

solid to gas

opposite of melting

solidification

As temperature increases

solubility increases

What is the energetic factor affecting solubility when a gas solute dissolves in a liquid solvent?

solute-solvent

What are alloys?

substances made from two or more different metals mixed together

Ion-dipole attractions

the intermolecular forces between ions and polar molecules

As gas solubility increases

the pressure of the gas increases

Raoult's Law

the vapor pressure of a solution is directly proportional to the mole fraction of solvent present

octahedral interstitial site

triangle top and bottom

tetrahedral interstitial site

triangle top atom on bottom