CHEM 1128 ACS FINAL EXAM PRACTICE ANSWERS ON THE LAST PAGE|A+GRADE
Molarity (M) - (ANSWER)moles solute/liters solvent
Mole Fraction (X) - (ANSWER)moles A/total moles. The sum of all mole fractions is 1
Mass Percent - (ANSWER)mass solute/total mass solution x 100%
Molality - (ANSWER)moles solute/kg solvent
Effect of temperature on solubility equilibria - (ANSWER)an increase in temperature always shifts the
position of an equilibrium to favor an endothermic process. So, if the process is endothermic (∆H>0),
solubility increases and if ∆H<0, solubility decreases
Relationship between concentration and solubility (Henry's Law) - (ANSWER)Cg=kPg where C is
concentration, P is the partial pressure of the gas.
Colligative Properties - (ANSWER)properties that depend primarily on concentration of solute particles
such as vapor pressure, freezing pt depression, etc
Vapor Pressure Lowering - (ANSWER)P₁=X₁P₁° where P₁ is the vapor pressure of the pure solvent, X₁ is the
mole fraction of the solvent, P₁° is the vapor pressure of the pure solvent at that temperature. Also
expressed as ∆P=X₂P₁° where X₂ is the mole fraction of the solute
Boiling Point Elevation/Freezing Point Depression - (ANSWER)∆T=km where m is molality, k is a given
constant
Osmotic Pressure - (ANSWER)π=MRT where M is molarity, R is the gas law constant .0821, and T is the
temperature in Kelvins
Van't Hoff Factor - (ANSWER)number of moles of particles in solution (for electrolytes only), for
electrolytes multiply colligative property equations by i
Molarity (M) - (ANSWER)moles solute/liters solvent
Mole Fraction (X) - (ANSWER)moles A/total moles. The sum of all mole fractions is 1
Mass Percent - (ANSWER)mass solute/total mass solution x 100%
Molality - (ANSWER)moles solute/kg solvent
Effect of temperature on solubility equilibria - (ANSWER)an increase in temperature always shifts the
position of an equilibrium to favor an endothermic process. So, if the process is endothermic (∆H>0),
solubility increases and if ∆H<0, solubility decreases
Relationship between concentration and solubility (Henry's Law) - (ANSWER)Cg=kPg where C is
concentration, P is the partial pressure of the gas.
Colligative Properties - (ANSWER)properties that depend primarily on concentration of solute particles
such as vapor pressure, freezing pt depression, etc
Vapor Pressure Lowering - (ANSWER)P₁=X₁P₁° where P₁ is the vapor pressure of the pure solvent, X₁ is the
mole fraction of the solvent, P₁° is the vapor pressure of the pure solvent at that temperature. Also
expressed as ∆P=X₂P₁° where X₂ is the mole fraction of the solute
Boiling Point Elevation/Freezing Point Depression - (ANSWER)∆T=km where m is molality, k is a given
constant
Osmotic Pressure - (ANSWER)π=MRT where M is molarity, R is the gas law constant .0821, and T is the
temperature in Kelvins
Van't Hoff Factor - (ANSWER)number of moles of particles in solution (for electrolytes only), for
electrolytes multiply colligative property equations by i
