Respiratory Lab

Introduction: External gas exchange is a process that takes place between the air and lungs. Oxygen travels into the blood from the air throughout the alveoli and carbon dioxide travels to the alveoli by first travelling from air and into the blood stream, this is possible by cellular respiration.

Part A: In the first part of the respiratory lab we were required to expose limewater to oxygen and carbon dioxide while residing in test tubes. Test tube A was aerated by oxygen and test tube C was aerated by carbon dioxide and to do so we had to breathe into a straw into the tube for a certain time. After the experiment we saw that test tube A had a few bubbles during but was particularly still afterwards and test tube C was cloudy and a greyish white colour. 

before

during

after

Part B: In the second part of the respiratory lab we were required to expose distilled water to oxygen and carbon dioxide while residing in beakers. Beaker C was aerated by oxygen and beaker D was aerated by carbon dioxide and do so we had to breathe into a straw for a certain time. After the experiment we saw that beaker C which was supposed to turn a green colour but because of our dysfunctional beaker it turned orange and beaker D turned a yellowish colour. Therefore the aerated distilled water was neutral whereas the one that was breathed into was a strong acid. 

 before

after

Part C: In the third and final part of the respiratory lab some students were required to track the amount of breaths taken in one minute and the breaths taken in thirty seconds into a paper back. Here are the results.

Breaths In One Minute:

28

25

18

Breaths In Thirty Seconds Into A Paper Bag:

10

14

18

The amount of breaths taken in thirty seconds should be higher because of the restriction of the paper bag, but on average the number was half the amount if the breaths taken in the minute.

Questions:

Part A.)

1. The colour change in the limewater when aerated by the carbon dioxide indicated that the carbon dioxide that we breathe out had reacted with the limewater to create a solid precipitate.

2. The purpose of the control test tube is to observe the differences being shown between test tube C and test tube A and to observe what had caused the limewater to change. It had shown what caused the change and in this experiment it was the breathing into the limewater.

Part B.)

3. The colour change after using the universal indicator presents that the carbon dioxide we breathe out is acidic and the oxygen that was aerated is neutral.

4. The purpose of the control beaker is to observe the differences being shown between beaker C and beaker D and to observe what had caused the distilled water to change and to further compare the two.

5. In use of oxygen and carbon dioxide to experiment upon distilled water the final result had looked to be the same, but upon using the universal indicator did you see the actual results. Beaker C which was aerated by oxygen had supposed to turn a green colour and that indicated it was neutral, and beaker D which was exposed to carbon dioxide turned a yellow colour that indicated it was acidic. 

7. Our blood cannot become acidic because of the HHB in our blood, HHB are hydrogen with hemoglobin molecules that do not become acidic. 

8. The breathing rate at thirty seconds increased because of breathing into the paper bag indicating limited oxygen being breathed in and caused the body to react.