Question

Experiment 1: Observe the Reactions Between Halide and Calcium Ions

Take four test tubes from the Containers shelf and place them on the workbench.

Fill each test tube with a different halide solution from the Materials shelf, as directed below. You may want to label the test tubes by double-clicking on each test tube and renaming it.

Test Tube #	Halide Solution
1	10.5 mL 0.1 M sodium chloride
2	10.5 mL 0.1 M sodium fluoride
3	10.5 mL 0.1 M sodium iodide
4	10.5 mL 0.2 M potassium bromide

Take 0.5 M calcium nitrate from the Materials shelf and add 4.5 mL to each of the four test tubes. You may want to use the + or – zoom buttons in the lower right of the screen for a closer view. Record any evidence of a reaction with each of the four halide ions in your Lab Notes. Remember to press Save Notes.

Dispose of the four test tubes by dragging them to the recycling bin beneath the workbench.

Experiment 2: Observe the Reactions Between Halide and Silver Ions

Prepare another set of four test tubes with the halogen ions as described in steps 1 and 2 of experiment 1.

Take 0.1 M silver nitrate from the Materials shelf and add 4.5 mL to each of the four test tubes. Observe and record any evidence of a reaction with each of the four halide ions in your Lab Notes. You may want to zoom in for a closer look.

Dispose of the four test tubes by placing them in the recycling bin.

Experiment 3: Observe the Reactions Between Silver Halides and Ammonia

Take four 50 mL beakers from the Containers shelf and place them on the workbench.

Fill each beaker with a different halide solution from the Materials shelf, as directed below. You may want to label the beakers by double-clicking on each one and renaming it.

Beaker #	Halide Solution
1	10.5 mL 0.1 M sodium chloride
2	10.5 mL 0.1 M sodium fluoride
3	10.5 mL 0.1 M sodium iodide
4	10.5 mL 0.2 M potassium bromide

Take 0.1 M silver nitrate from the Materials shelf and add 4.5 mL to each beaker. Observe and record any evidence of a reaction with each of the four halogen ions in your Lab Notes.

Take 4 M ammonia from the Materials shelf and add 4.5 mL to each beaker. Observe and record any evidence of a reaction with each of the four halogen ions in your Lab Notes.

Dispose of the four beakers by placing them in the recycling bin.

Experiment 4: Observe the Reactions Between Silver Halides and Sodium Thiosulfate

Prepare another set of beakers with the halide ions as described in steps 1 and 2 of experiment 3.

Take 0.1 M silver nitrate from the Materials shelf and add 4.5 mL to each beaker. Observe and record any evidence of a reaction with each of the four halogen ions in your Lab Notes.

Take 0.2 M sodium thiosulfate from the Materials shelf and add 4.5 mL to each beaker. Observe and record any evidence of a reaction with each of the four halogen ions in your Lab Notes.  

Dispose of the four beakers by placing them in the recycling bin.

Experiment 5: Identify Unknown Halides

On the Materials shelf, there are two unidentified halide solutions. Each solution contains one of the four halide ions from the previous four experiments. Identify them using the reagents and the results from the first four experiments.

Question 13. In experiment 5, which unknown halide formed a precipitate when reacted with silver nitrate?

A. Only unknown halide 1 formed a precipitate

B. Only unknown halide 2 formed a precipitate

C. Both halides formed precipitates

D. None of the halides formed a precipitate

Question 15. Based on your observations, what is the identity of unknown #1?

A. sodium iodide or sodium fluoride

B. potassium bromide

C. sodium fluoride

D. sodium chloride

Question 16. Based on your observations, what is the identity of unknown #2?

A. sodium chloride

B. potassium bromide

C. sodium iodide

D. sodium fluoride

Answer 1