Topic 4.1 Flashcards
solutes can dissolve in ? to make ?
solvents and solutions
liquid that solute dissolves in
solvent
Name a polar and nonpolar solvent
water and hexane
explain why methanol is a polar molecule
Methanol has a polar OH region. The nonpolar hydrocarbon region is relatively small and has small affect on overall molecule polarity.
Do polar and nonpolar substances readily mix?
no
Why don’t polar molecules mix with nonpolar molecules?
Polar molecules have stronger secondary forces than nonpolar molecules and more attracted to polar molecules.
Explain why O2 (nonpolar) molecules do not readily mix in water
Nonpolar o2 molecules do not readily form secondary forces with polar water molecules.
State and explain whether I2 molecules readily mix with hexane solvent or not
I2 molecules readily mix with hexane. nonpolar i2 molecules readily form secondary forces with nonpolar hexane molecules.
Define miscibility
ability of two substances to mix together homogeneously
State and explain whether NH3 or PH3 is more soluble in water
NH3 is more polar than PH3 and forms stronger secondary forces with polar water molecules. Therefore, NH3 is more soluble in water than PH3.
Explain how size impacts the solubility of molecules
Substances with smaller molecules are more soluble than larger molecules of similar polarity
Explain why glucose is highly soluble in water while starch is insoluble, despite both being highly polar
Glucose is a small molecule and can readily form secondary interaction with polar water molecules. However starch is a large molecule which can form secondary interaction with itself, but forms secondary interaction with water less readily.
What is an amphiphilic substance?
A compound that can interact with and dissolve in both polar and nonpolar solvents
Explain why ethanol can dissolve in nonpolar octane
Ethanol contains a nonpolar hydrocarbon region which can readily form dispersion force with nonpolar octane molecule
Explain how soap can remove grease off from the surface effectively when scrubbed and rinsed
Soap anions forms micelle with the grease of the fat. The nonpolar hydrocarbon tail readily forms secondary interaction with nonpolar grease and repels water. The polar hydrophillic tail readily forms secondary forces with the polar water. Grease is removed.
