Mass of Alka Seltzer and Water - Conclusions

Mass of Alka Seltzer and Water - Conclusions

Mass of Alka Seltzer and Water

• PURPOSE/QUESTION: Does the mass of solid alka seltzer and water separately, increase decrease, or does not change when the alka seltzer and water are mixed?

Mass of Alka Seltzer and Water

In just a moment, we are going to watch a video demonstration of our laboratory experiment. Take observations on what happens when the Alka seltzer is introduced to the water:

Open Ended

What did you observe when the Alka seltzer is mixed with the water?

Is this an example of an open or a closed system?

In just a moment, we will watch a video where the scientist leaves the water and alka seltzer mixture on the balance while the tablet is dissolving. Pay close attention to the numbers on the scale! Do they increase, decrease or stay the same? How does this help explain whether our system is open or closed?

Multiple Choice

During the video demonstration, the mass of the system:

• Increased

• Decreased

• Did not change

Open Ended

Is this lab an example of an open or a closed system? Use evidence from the balance demonstration to justify your response:

The system is open!

• As the alka seltzer dissolves, we observe the values on the balance decreasing.

• Since mass/matter cannot be created or destroyed, particles must be leaving the system. The beaker/flask is open during the duration of the demonstration. Hence, particles can move in or out of the system.

What happens if we close our system?

In the next video clip, we will turn our open system into a closed system by covering the top of the glassware with a flexible lid. Take observations on how our balloon changes are the Alka seltzer is dissolved:

Open Ended

What did you observe as the Alka seltzer dissolved in the closed system?

Gas is formed as the alka seltzer is dissolved:

• As observed in the close system example, as the Alka seltzer is dissolved, a gas is formed.

• When the system is closed by a flexible lid, we can observe the gases that have been released when then become trapped and inflate the balloon.

Open Ended

During this lab, did the mass change? Justify your answers using data and observations from the lab!

Open Ended

Did mass enter or leave the system during this lab? Justify your answers using data and observations from the lab!

Open Ended

Was mass created destroyed or neither? Justify your answers using data and observations from the lab!

Open Ended

Was the lab an example of a chemical or physical change? Justify your answers with evidence and observations from the lab!