1/10/2024 SOLUTIONS & CONCENTRATION Flashcards
Why does research often start with solutions?
- water is cheap
- chemical behavior of solutions
What are the properties of solutions?
- solutions contain SOLUTES dissolved in a SOLVENT
- SOLUTES can DISSOCIATE into ions in SOLVENTS
(ex: sodium chloride dissociates into water) - “dissociating into ions” is much better than saying “dissolving”
What is distilled water?
boiled and condensed over and over again so it has NOTHING in it!
* can’t conduct charge like a solution with dissolved molecules
Can solutions with dissolved solute ions conduct electricity?
YES!
What is a “strong electrolyte”?
- Produces a solution containing charged ions
- NaCl
- KCl
What is a “weak electrolyte”?
- Does not fully dissociate into ions
- Acetic Acid (vinegar in water)
What is a “non-electrolyte”?
- Ethanol
- Sugar
How do you get a good grade in 107?
Make solutions properly! (look at slides)
Define Concentration
the numerical amount of solute dissolved in a solvent
Define Concentrated. What is the threshold?
a relatively large amount of solute is dissolved in a solvent
* 0.1M is the threshold
Define Dilute
not concentrated
What is dimensional analysis?
A method for converting quantities between units
(ex: “how many atoms are there in 1.00g of Pb?”)
How do we get from grams to # of atoms in dimensional analysis?
MOLES (mol/gram)
MOLAR CONCENTRATION:
What is “molarity”?
Molarity = moles per volume (# of moles/v)
OTHER CONCENTRATION UNITS:
What is parts per million (ppm)?
ppm = solute mg / solvent kg
- 1.4 mM = 0.0014 mol
