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Chemistry

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1). What was the mass of the empty, open Erlenmeyer flask?

A.50.000 g

B.88.000 g

C.185.000 g

D.34.000 g

2. What was the mass of the Erlenmeyer flask with the 5% vinegar?

A.189.194 g

B.138.133 g

C.88.000 g

D.139.061 g

3. What did you observe when you combined the sodium hydroxide and vinegar?

A.The solution turned pink because a salt was formed.

B.Nothing happened, because sodium hydroxide does not react with vinegar.

C.The solution started bubbling because a gas was formed.

D.The temperature increased, but no other visible signs were observed.

4. What was the mass of the vinegar solution added to the Erlenmeyer flask?

A.88.000 g

B.50.133 g

C.138.133 g

D.51.061 g

5. What can be said about the mass of the 5% vinegar and 1 M NaOH after they were combined?

A.The combined mass of the 5% vinegar and 1 M NaOH could not be determined from the experiment.

B.The combined mass of the 5% vinegar and 1 M NaOH was lower than their respective masses.

C.The combined mass of the 5% vinegar and 1 M NaOH was the sum of their respective masses.

D.The combined mass of the 5% vinegar and 1 M NaOH was higher than their respective masses.

6. What was the mass of the closed Erlenmeyer flask with the water and Alka Seltzer?

A.88.000 g

B.2.000 g

C.109.545 g

D.110.155 g

7. What did you observe after adding the Alka Seltzer to the water?

A.There was no observable change after the addition of Alka Seltzer.

B.There was a precipitation reaction in the Erlenmeyer flask.

C.There was a color change from white to blue.

D.There was bubbling in the Erlenmeyer flask.

8. What was the pressure in the Erlenmeyer flask after the addition of the Alka Seltzer to the water? Select the closest answer.

A.2.9 kPa

B.1.0 atm

C.1.2 atm

D.2.9 atm

9. What was the pressure inside the Erlenmeyer flask after you opened it?

A.0.75 atm

B.1.00 atm

C.1.24 atm

D.2.94 atm

10. What happened to the pressure inside the Erlenmeyer flask, as compared to normal atmospheric pressure, after the addition of Alka Seltzer to the water?

A.The pressure decreased.

B.The pressure did not change.

C.The pressure increased.

D.The pressure started fluctuating.

11. What could account for the change in pressure inside the flask that you observed after the addition of the Alka Seltzer?

A.The fluctuations in room pressure caused an increased in the pressure inside the flask.

B.The reaction between water and Alka Seltzer produced a gas that got trapped inside the closed flask.

C.The reaction between water and Alka Seltzer was exothermic and caused the pressure to decrease.

D.The reaction between water and Alka Seltzer used some of the air trapped inside the closed flask.

12. What could account for the change in mass that you observed after opening the flask at the end of the reaction between water and Alka Seltzer?

A.The gas produced in the reaction escaped the flask causing an increase in mass.

B.The gas produced in the reaction escaped the flask causing a decrease in mass.

C.Some of the solution got spilled causing a decrease in mass.

D.More air entered the flask causing an increase in the mass.

13. A student performs an experiment similar to experiment 1 using hydrochloric acid (HCl) and potassium hydroxide (KOH). The mass of the hydrochloric acid solution is 250.000 g. After combining the HCl and KOH, the final combined mass is 400.000 g. Given what you have learned about the conservation of mass in this experiment, what must have been the mass of the KOH solution?

14. Who was the scientist that developed the Law of Conservation of Mass?

A.Rutherford

B.Dalton

C.Lavoisier

D.Avogadro

 

15. Suppose a student reacted calcium carbonate with hydrochloric acid in an Erlenmeyer flask to produce carbon dioxide gas. Given the data in the figure below, how many grams of gas were produced in his reaction? 4.401g

16. Zinc reacts with hydrochloric acid with the formation of zinc chloride and hydrogen gas. What do you expect will happen to the pressure inside the reaction flask if it is closed with a rubber stopper before the reaction?

A.The pressure will increase.

B.The pressure will not change.

C.The pressure will decrease.

D.The pressure will change randomly.