Giving Directions - Dec2 Class

In today's class, we learned about which procedures we should use when it comes to concentrations. We also did a pre-lab about how much water we would need to dissolve Copper Chloride completely. We will be doing the lab this friday, Dec4.

Outline for experimental procedures:
- Find the mass you need

Johnny is asked to make 0.95M solution of K2S04. If he needs 300mL, what procedure should he use?
Con'c -> moles -> mass

Give directions to make 3.5 L of 4.5M NaOH

DILUTIONS OF SOLUTIONS
- When you add water, con'c decreases. If the volume is doubled, con'c is halved.

N1 = N2
C1V1=C2V2
Lauren adds 215.0 mL of water to 25.0 mL of 0.8M HCl. Find [HCl]
Janice adds water to 75.0 mL of 0.15M HF to a final volume of 310mL. Find the [HF]
Nicola dilutes 75.0 mL of 0.30M HNO3 to 0.10M. What is the final volume?

How much water did she add?
225mL-75mL = 150mL