flask Solutions & Solubility
Most chemistry happens in solution. Learn to express concentration six ways, dilute stock solutions accurately, predict precipitation, and explain why salt melts ice and antifreeze protects engines.
What you will learn
- Express concentration in multiple units
- Perform dilution calculations
- Predict precipitation
- Explain colligative properties
- Use solubility rules
Introductory College concepts
Boiling-point elevation: why solutions boil hotter
Dissolved solute raises the boiling point. Learn the dTb = i Kb m relationship, work a NaCl example, and see applications from antifreeze to candy making.
Colligative properties: when only particle count matters
Colligative properties depend on particle count, not identity. Explore vapor-pressure lowering, boiling-point elevation, freezing-point depression, and osmotic pressure.
Freezing-point depression: antifreeze and de-icing explained
Dissolved solute lowers the freezing point. Learn dTf = i Kf m, work an antifreeze example, and explore de-icing and molar-mass determination.
Osmotic pressure: the force behind osmosis
Osmotic pressure is the pressure needed to stop osmosis across a membrane. Learn pi = iMRT, work a numerical example, and see how reverse osmosis desalinates seawater.
High School concepts
Dilution: lowering concentration with M1V1 = M2V2
Dilution lowers concentration by adding solvent. Learn the M1V1 = M2V2 equation, how to prepare dilutions from stock, and the acid-to-water safety rule.
Mass percent: concentration in parts per hundred
Mass percent gives concentration in parts per hundred. Learn the w/w, w/v, and v/v bases, how to prepare percent solutions, and how to convert them.
Molality: concentration per kilogram of solvent
Molality measures concentration as moles of solute per kilogram of solvent. Learn why it is temperature independent and how to calculate it.
Molarity: the concentration chemists use every day
Learn what molarity means, how to compute M = moles of solute per liter of solution, and how to prepare a solution of known molarity in the lab.
Mole fraction: composition as a share of total moles
Mole fraction expresses each component as a share of total moles, a dimensionless number. Learn to calculate it and why the fractions sum to 1.
Precipitation: when ions form an insoluble solid
Precipitation forms an insoluble solid when ions meet in solution. Learn to predict precipitates, write net ionic equations, and identify spectator ions.
Solubility rules: predicting what dissolves
Solubility rules predict which ionic compounds dissolve in water. Study the always-soluble groups, the key exceptions, and a compact reference table.
Formulas
Dilution Equation M1V1 = M2V2
M1 x V1 = M2 x V2
Freezing Point Depression
delta Tf = Kf x molality x i
Mass Percent Composition
mass percent = (mass of solute / mass of solution) x 100%
Molality Definition
molality = moles of solute / kg of solvent
Molarity Definition
Molarity = moles of solute / liters of solution
Mole Fraction
X(i) = moles of component i / total moles