1. Warm up - Solutions

2. Warm up #1
To analyze the alcohol content of a certain wine a chemist needs 1000 ml of an aqueous 0.200M solution of K2Cr2O7.
Calculate how many grams are needed and draw a picture of how to make the solution.
Molar mass – g/mol

3. 1000. mL of 0.200 M K2Cr2O7 from solid K2Cr2O7.( )
0.200 moles K2Cr2O7
1.000L
= mol K2Cr2O7
1.00 L ( )
294.2 g KMnO4
0.200 mol KMnO4
= 58.8 g K2Cr2O7
1 mol KMnO4

4. K2Cr2O7
Detailed Directions: Dissolve _____ g of _______ in enough water to prepare _______ mL of solution. Diagram steps below:
58.8
1000.
58.8 g
K2Cr2O7
Dissolve
Add water to 250 ml

5. - If we use 1.0L (1000ml) of SOLVENT, what will happen?
M = mol / L
- Do we need to know the exact amount of water added?
The 58.8 g is the ….
Solute
Solvent
Solution
The water added is the..
Solute
Solvent
Solution

6. Warm up #2
Provide a detailed directions for the preparation of 750. ml of 0.25 M HCl by dilution of a 12M HCl stock solution.

7. 4. 750. mL of 0.25 M from 12 M (concentrated) HCl stock solution.
Solve for..
Mc = 12 M
Vc = ?
Md = 0.25 M
Vd = 750. ml
McVc = MdVd
Vc =
Md * Vd Mc
Vc =
0.25 mol/L * 750. ml
12 mol/L =
16 ml

8. 12
Recipe: Dilute ____ mL of the _____ M stock solution with enough water to prepare _______ mL of solution.
Diagram steps below: 16
750
750. ml
16 ml of
12 M
stock
mix
750 ml of 0.25M solution