CHEM 162 TRAINING STUDY SHEET 2026
UPDATED QUESTIONS AND ANSWERS
◉What is the role of propylene glycol in automotive engines?
Answer: It replaces ethylene glycol due to its lower toxicity and
allows a wide temperature range for coolant.
◉What happens to the van't Hoff factor (i) when ion pairing occurs?
Answer: The van't Hoff factor (i) is lower than expected due to fewer
ions in solution.
◉What is the osmotic pressure (Π) equation? Answer: Π = iMRT
◉What does a semipermeable membrane do? Answer: It selectively
allows some substances to pass through while blocking others.
◉What is osmosis? Answer: The flow of solvent from a solution of
lower solute concentration to one of higher solute concentration.
◉What is the molarity (M) formula? Answer: M = mol solute / L
solution
,◉How do you calculate the molar mass (Mm) of a solute using
colligative properties? Answer: Use ΔTf, ΔTb, or Π to find m or M,
then calculate Mm using the moles of solute.
◉What is the osmotic pressure of a solution with 35.2 torr at 298 K?
Answer: 0.04631 atm
◉How many moles of solute are in 20.0 mL of a solution with a
molarity of 0.001893 mol/L? Answer: 0.00003786 mol
◉What is the calculated molar mass of a protein if 1.00 g is dissolved
in 20.0 mL with an osmotic pressure of 35.2 torr? Answer: 26413
g/mol
◉What is the typical concentration of normal saline (NS)? Answer:
0.90% w/v NaCl, approximately 300 mOsm/L
◉What is the osmolarity of normal saline in terms of mEq/L?
Answer: 154 mEq/L of Na+ and Cl−
◉What is the molecular weight of sodium chloride (NaCl)? Answer:
Approximately 58.5 grams per mole.
, ◉What is the significance of the osmotic coefficient for NaCl?
Answer: It corrects for non-ideal solutions, making osmolarity closer
to isotonic.
◉What is mass percent? Answer: The mass of the solute divided by
the mass of the solution, multiplied by 100.
◉How is ppm calculated? Answer: Mass of the solute divided by the
mass of the solution, multiplied by 1,000,000.
◉What does ppb stand for? Answer: Parts per billion, calculated as
mass of the solute divided by the mass of the solution, multiplied by
1,000,000,000.
◉What is the formula for calculating molality? Answer: Molality (m)
is calculated as moles of solute divided by kilograms of solvent.
◉How do you calculate volume percent? Answer: Volume of the
solute divided by the volume of the solution, multiplied by 100.
◉What is the formula for calculating ppm by volume? Answer:
Volume of the solute divided by the volume of the solution,
multiplied by 1,000,000.
UPDATED QUESTIONS AND ANSWERS
◉What is the role of propylene glycol in automotive engines?
Answer: It replaces ethylene glycol due to its lower toxicity and
allows a wide temperature range for coolant.
◉What happens to the van't Hoff factor (i) when ion pairing occurs?
Answer: The van't Hoff factor (i) is lower than expected due to fewer
ions in solution.
◉What is the osmotic pressure (Π) equation? Answer: Π = iMRT
◉What does a semipermeable membrane do? Answer: It selectively
allows some substances to pass through while blocking others.
◉What is osmosis? Answer: The flow of solvent from a solution of
lower solute concentration to one of higher solute concentration.
◉What is the molarity (M) formula? Answer: M = mol solute / L
solution
,◉How do you calculate the molar mass (Mm) of a solute using
colligative properties? Answer: Use ΔTf, ΔTb, or Π to find m or M,
then calculate Mm using the moles of solute.
◉What is the osmotic pressure of a solution with 35.2 torr at 298 K?
Answer: 0.04631 atm
◉How many moles of solute are in 20.0 mL of a solution with a
molarity of 0.001893 mol/L? Answer: 0.00003786 mol
◉What is the calculated molar mass of a protein if 1.00 g is dissolved
in 20.0 mL with an osmotic pressure of 35.2 torr? Answer: 26413
g/mol
◉What is the typical concentration of normal saline (NS)? Answer:
0.90% w/v NaCl, approximately 300 mOsm/L
◉What is the osmolarity of normal saline in terms of mEq/L?
Answer: 154 mEq/L of Na+ and Cl−
◉What is the molecular weight of sodium chloride (NaCl)? Answer:
Approximately 58.5 grams per mole.
, ◉What is the significance of the osmotic coefficient for NaCl?
Answer: It corrects for non-ideal solutions, making osmolarity closer
to isotonic.
◉What is mass percent? Answer: The mass of the solute divided by
the mass of the solution, multiplied by 100.
◉How is ppm calculated? Answer: Mass of the solute divided by the
mass of the solution, multiplied by 1,000,000.
◉What does ppb stand for? Answer: Parts per billion, calculated as
mass of the solute divided by the mass of the solution, multiplied by
1,000,000,000.
◉What is the formula for calculating molality? Answer: Molality (m)
is calculated as moles of solute divided by kilograms of solvent.
◉How do you calculate volume percent? Answer: Volume of the
solute divided by the volume of the solution, multiplied by 100.
◉What is the formula for calculating ppm by volume? Answer:
Volume of the solute divided by the volume of the solution,
multiplied by 1,000,000.
