Solutions
Medium in which a solute is added to in order to dissolve
What is solvent?
Based on colligative properties, you have two solutions, A and B, each containing the same type of solute, but B contains a higher concentration.
Which one has a higher boiling point?
What is solution B?
What are the units for Molarity?
What is moles/L?
Based on the Brownstead-Lowrey definition of acids and bases. The acid donates what?
What is H+ (proton)?
Used in a lab setting when you want to find the concentration of an acid/base
What is a titration?
Thinking about solubility rules, polar compounds dissolve in _______ solutions
What is polar?
Remember, like-dissolves-like!
If you put a cell into a hypotonic solution, what happens to the cell?
What is swell/burst?
HYPO = less
Less concentration in the surroundings, so water will want to seep into the cell because of osmotic pressure.
You put 3 mols of K2NO3 into 500 mL of water, what is the concentration (in molarity?)
What is 6M?
(500 mL)(1 L /1000 mL) = 0.5 L
3 mols K2NO3 / 0.5 L = 6 M.
If the acid dissociation constant (Ka) is extremely small, this tells you that the acid you added is:
What is weak acid?
What is the end point?
Say you have a saturated solution with some solute still remaining at the bottom.
What happens if you increase the temperature?
What is more solute dissolve? (solubility increases)
You want to make chocolate milk and generally like to maintain a 15% chocolate sauce/milk ratio.
If you make yourself a 180 mL glass of chocolate milk, how much mL of chocolate sauce did you use?
180 mL chocolate milk (15 mL chocolate sauce / 100 mL milk)
=27 mL chocolate sauce
What is ~1.8 mols?
Molarity = Mols/L
Mols = Molarity * L.
0.50 L * 3.5 (mols/L) = ~1.8 mols
For each mole NaCl, there is 1 mole Na.
Based on the following equation:
HBr (g) + H2O (l) -> H3O+(aq) + Br-
Which of the reactants is the acid, and which is the base?
What is HBr (acid) and H2O (base)?
What is the purpose of a buffer?
What is allows the pH to not change as drastically when adding an acid/base?
Essentially reduces the "effect" it has on the pH.
The following compounds are ____ in water:
1. NaSO4
2. BaCl2
3.KClO4
What is soluble?
You have 3.0 M of a 850 mL solution, how concentrated would your solution be if you wanted to dilute it to 1.5 L?
What is 1.7 M?
MdilVdil=MconcVconc
850 mL * (1 L/1000 mL) = 0.850 L.
Mdil = (3.0 M * 0.850 L) / 1.5 L
Mdil = 1.7 M
You want a 3.5 M solution and only have 6.3 mols of MgCl2, how much water do you need to add?
What is 1.8 L water?
Molarity = Mols/L
Molarity * L = Mols
L = Mols / Molarity
6.3 mols / 3.5 M = 1.8 L.
You put the NH4NO3 salt into a flask of water, which will dissociate into NH3 (weak base) + HNO3 (strong acid).
What can you expect to happen to to the pH of the solution?
What is lower/become more acidic?
It took 0.058 mols of KOH to reach the endpoint of a 40 mL sample of HCl. What is the concentration of the HCl you used?
What is
1:1 molar ratio of KOH and HCl
0.058 mols KOH used = 0.058 mols HCl used.
M = (mols/L), so 40 mL (1 L/1000 mL) = 0.040 L.
0.058 mols HCl / 0.040 L HCl = 1.45 M HCl
If you dissolve the following salt pairs into water, which one will form a precipitate?
-K2SO4 + MgCl2
-NaCH3OO + KNH4
-Pb(NH4)2 + NaF
- LiF + RbNO3
What is -Pb(NH4)2 + Na2CO3?
Will form PbCO3, which is NOT soluble in water.
If you have an aqueous solution with 5 M NaCl, what is the freezing point of the solution?
Note: Freezing point depresses 1.86 C / mol for each particle.
What is -18.6 C?
(5.0 mol NaCl/ L) * (2 mols particles/ 1 mol NaCl) * (1.86 C / 1 mol particles) ~18.6 C.
Freezing point of water = 0.0 C, so...
0.0 C - 18.6 C = -18.6 C.
You have 167 mg of KBr and want to put it in a 12 mL solution of water. What is the concentration you created?
What is ~0.117 M
KBr = ~119 g / mole
167 mg KBr (1 g/ 1000 mg) = 0.167 g
0.167 g KBr (1 mol/119 g) = 0.00140033 mols
12 mL (1 L/1000 mL) = 0.012 mL
0.00140033 mols / 0.012 mL = 0.117 M
Knowing that:
Kw = 1.00 x 10-14 M
Kw = [OH-][H3O+]
pH = -log[H3O+]
An unknown solution has [OH-] = 1.00 x 10-8 M
What is the [H3O+], and what is the pH?
What is 1.00 x 10-6 M and 6?
(1.00 x 10-14) / (1.00 x 10-8) = 1.00 x 10-6 M
pH = -log(1.00 x 10-6) = 6.
You have 25 mL of NaOH in a container and use a total of 28.4 mL of 3M HCl to reach the end point.
What is the concentration of the NaOH used?
What is 3.4 M?
28.4 mL (1 L/1000 mL) = 0.0284 L
(3 mols/L HCl) * (0.0284 L) = 0.0852 mols HCl.
1:1 ratio for HCl and NaOH = 0.0852 mols NaOH
25 mL NaOH (1 L/1000 mL) = 0.025 L
M NaOH = 0.0852 mols / 0.025 L = 3.4M.