Activity 40 Follow-up. Understanding Serial Dilutions and Concentration. One drop of red dye solution. One drop of water. Activity 40 Analysis. Which is more dilute, Cup 1 or Cup 2? How do you know this? Cup 2 The color in cup 2 is lighter
Understanding Serial Dilutions and Concentration
One drop of water
Which cup has a concentration of one part of food coloring per one million parts of solution?
Do you think there is any food coloring in Cup 8, even though it appears colorless? Explain.
Look at the tray with evaporated solutions
Title: Precipitating Specific
Problem: How can you use a chemical reaction to remove a contaminant from a solution?
Copper chloride + sodium carbonate copper carbonate + sodium chloride
Make comparisons in your descriptions like, “lighter than or less than test 1”
Table: Precipitation Reaction
One pair do tests 1 and 2
Make observations before and after you mix them
One pair do tests 3 and 4
Follow the instructions on your table to determine the number of drops of water and sodium carbonate you add to Cups B and C
Test 1 or 3
Test 2 or 4
Write down what you see before you stir the mixture and after you stir the mixture. Be descriptive!Examples: blue, bluish-green, fluffy solid, cloudy, thick, darker blue than…, clear, pasty, fizzing, chunks, precipitate
Using the dropper, transfer as much as you can of the material from Cup B to the filter in Cup D. Rinse the dropper and transfer Cup C material to E.
Once the mixtures have filtered, observe the appearance and quality of the filter paper. Then put the filters in a paper towel and put them in the trash. Observe the appearance and quantity of the filtrate. Finish filling in the data table on your student sheet.
Add 1 one drop of sodium carbonate and observe any change. Continue to add a drop at a time pausing for observation until you reach 10.