1. Steel Wool Lab Day 2 Gathering Data & Making Sense Out of It

2. What normally happens when steel (iron) gets wet in the presence of air? 1.The iron dissolves into the water 2.The water gets absorbed by the iron 3.The iron will slowly rust 4.Absolutely nothing will happen because they do not chemically react with each other

3. What normally happens when steel (iron) gets wet in the presence of air? 1.The iron dissolves into the water 2.The water gets absorbed by the iron 3.The iron will slowly rust 4.Absolutely nothing will happen because they do not chemically react with each other

4. If a gas is removed in this reaction, what should happen to the water level in the test tube? 1.It will go up 2.It will go down 3.It will not change

5. If a gas is removed in this reaction, what should happen to the water level in the test tube? 1.It will go up 2.It will go down 3.It will not change

6. Which gas do you think is removed in this process? 1.Hydrogen 2.Nitrogen 3.Argon 4.Oxygen

7. Which gas do you think is removed in this process? 1.Hydrogen 2.Nitrogen 3.Argon 4.Oxygen

8. The chemistry… Fe (Iron) + O 2 (Oxygen) Iron Oxide (Rust) + Fe 2 O 3

9. What is the state of matter for each of the parts of this chemical equation? Fe (Iron) + O 2 (Oxygen) Iron Oxide (Rust) 1.Iron is a solid, Oxygen & Iron Oxide are gases 2.Iron and Iron Oxide are solids, Oxygen is a gas 3.All 3 are gases 4.All 3 are solids

10. What is the state of matter for each of the parts of this chemical equation? Fe (Iron) + O 2 (Oxygen) Iron Oxide (Rust) 1.Iron is a solid, Oxygen & Iron Oxide are gases 2.Iron and Iron Oxide are solids, Oxygen is a gas 3.All 3 are gases 4.All 3 are solids

11. What is an important characteristic of solids vs. gases? 1.Solids cant become gases but gases can become solids. 2.Gases cant become solids, but solids can become gases. 3.Gases typically occupy much more space than solids 4.Solids typically occupy much more space than gases

12. What is an important characteristic of solids vs. gases? 1.Solids cant become gases but gases can become solids. 2.Gases cant become solids, but solids can become gases. 3.Gases typically occupy much more space than solids 4.Solids typically occupy much more space than gases

13. What ought to happen in our Lab: When the oxygen in the test tube recombines with the iron to make rust, it will occupy a much smaller space. Water will move into the test tube to occupy that spaceso the volume of the water in the test tube represents the volume of the air in the test tube that used to be occupied by oxygen.

14. So, what would it mean if we found that half of the test tube was filled with water when we checked our results? 1.There is no oxygen in air 2.20% of air is oxygen 3.50% of air is oxygen 4.80% of air is oxygen 5.100% of air is oxygen

15. So, what would it mean if we found that half of the test tube was filled with water when we checked our results? 1.There is no oxygen in air 2.20% of air is oxygen 3.50% of air is oxygen 4.80% of air is oxygen 5.100% of air is oxygen

16. What would it mean if we found that the water rose 8 cm high and the test tube was 10 cm tall? 1.There is no oxygen in air 2.20% of air is oxygen 3.50% of air is oxygen 4.80% of air is oxygen 5.100% of air is oxygen

17. What would it mean if we found that the water rose 8 cm high and the test tube was 10 cm tall? 1.There is no oxygen in air 2.20% of air is oxygen 3.50% of air is oxygen 4.80% of air is oxygen 5.100% of air is oxygen

18. Lets begin building our procedure for data collection: 1)Measure the height of the water in the test tube. WHY? The water represents… --the amount of oxygen that was removed from the air in the test tube.

19. What next? We could measure the height of the entire test tube and then divide the water height by the entire test tube heightbut that introduces a couple of errors. WHAT ARE THEY? --steel wool takes up some space --top of test tube is curved

20. We can get around those problems using something like this: EXPLAIN what we can do

21. Continue on your procedure: 2)Measure out 50 ml of water in a 50 ml graduated cylinder. 3)Slowly pour water from the cylinder into the test tube with the steel wool still in it. Pour until the water level reaches X cm from the top, where X represents your measurement from step 1. 4)Subtract the water volume remaining in the gradated cylinder from 50 ml. WHAT DOES THIS NUMBER REPRESENT? (Volume of gas in test tube at the end of the lab)

22. Finishing the Procedure: 5) Continue slowly pouring water into the test tube until it is filled to the top. 6) Subtract the water volume remaining in the gradated cylinder from 50 ml. WHAT DOES THIS NUMBER REPRESENT? (Volume of gas in test tube at the start of the lab) 7) Use subtraction to figure out the volume of the water that was in the test tube at the end of the lab.

23. Your Assignment: Carry out your procedure & record all measurements. (DO NOT LEAVE TODAY WITHOUT THE MEASUREMENTS) Complete the calculation of percent oxygen AND the remaining questions on the handout.