Solutions PHET LAB

How is electricity defined?

Using the Macro page, start by checking off the 'show values' in the concentration box. Begin shaking the NaCl until you get approximately 0.25 mol/L. Drag the conductivity circuit to the solution and place the electrodes (the green and red bar) in the solution. What do you notice? Draw a picture of the 'brightness' of the lightbulb.

Start adding water to the solution (fill to 2L). What proper term can you use to describe what you are doing to the solution? ________ [Take a look at the concentration]. Predict what will happen to the conductivity compared to the original solution, then drag the circuit into the solution. Make a comparison between the conductivity of the original solution to this one. Draw a pic of the lightbulb.

Using the faucet on the right of the container, release 1L of the solution so it is back to 1L. Predict what will happen to the conductivity? Now test the conductivity and take observations. Explain, using comparisons, what you noticed.

Predict what will happen to the concentration of the solution and the conductivity when you evaporate the water. Evaporate as much water as possible while keeping the conductivity circuit in the solution. Write down your findings and explain what you noticed.

Now complete steps 1 to 4 using sugar. Compare the salt solution and sugar solution. Write down any similarities and differences between the solutions.

Using the Micro page, add the NaCl to water to notice the effect of what is occurring to the molecules of salt. What happens to an ionic compound when it is added to water?

Reset the page. Now add the sucrose molecules to water. What happens to a covalent molecule when it is added to water?

Reset the page. Now add the NaCl again to the water. Add water to the 2L mark. Does this help you to explain why a diluted solution will conduct less electricity? Now evaporate the water until there is 0.5L. Does this further help explain why a solution conducts electricity?

Now evaporate all the water. What happens to the dissolved salt?