https://phet.colorado.edu/sims/html/molarity/latest/molarity_en.html

https://phet.colorado.edu/sims/html/molarity/latest/molarity_en.html

HYPOTHESIS:  Before starting the simulation formulate the hypothesis determining the relationship between volume of the solution, amount of solute and the morality?

Instruction: After you open Molarity Simulation select cobalt (II) nitrate solution as a solute.

1. Keep the Amount of Solute constant (medium settings).

2. Adjust Solution Volume to the settings listed in the table.

3. Record, in Table 1, Solution Concentration (Molarity) for each Solution Volume.

Table 1:

Amount of SoluteSolution VolumeSolution Concentrationmediumlowmediummediummediumhigh

4. Now, keep the solution Volume Constant (medium settings), and adjust Solute Amount, read and record in Table 2 the corresponding Solution Concentration.

Table 2.

Amount of SoluteSolution VolumeSolution Concentrationnonemediummediummediumlotsmedium

5. Based on your findings, answer the following questions:

a) when the solution volume increases, what happens to the solution concentration?

b) Is solution volume directly or inversely proportional to the molarity? Why?

c) when the solute amount increases what happens to the solution concentration?

d) is the amount of solute inversely or directly proportional to the molarity? Why?

SUMMARY:

6. Based on your answers for b) and d) determine the mathematical formula for molarity.

7. Was your hypothesis correct? Use 2-3 sentences to explain your answer.

Part 2.

Instructions: On the Molarity Simulation click on solution values.

1. For cobalt (II) nitrate solution set Solution Volume for 0.472 L and Solute Amount for 0.815 moles.

2. What is the concentration of cobalt (II) nitrate solution?

3. Cobalt (II) nitrate dissociates as follows:

 position: relative;"> ( 3)2( )⟶ 2+( )+2 −3( )Co(NO3)2(aq)⟶Co(aq)2++2NO3(aq)−

4. What is the concentration of cobalt(II) cations?

5. What is the concentration of nitrate anions? Explain your answer.