Lab 5-1B: Properties of Acids and Bases Lab Report

Name: Brandon Jansen

Date: Feb. 28, 2013

Block: D

How to Write a Science Lab Report

Use the following headings in order, for each lab write up. (Each heading should always be underlined with a ruler)

Title: Write down the name of the experiment or activity of the lab

Lab 5-1B: Properties of Acids and Bases                                                             (/2)

Purpose: Summarize in 1-2 sentences what you hope to explore or find out in this lab, based on the pre-lab material provided.         

What we hope to explore in this lab is to find if and what happens to the pH indicators if we add A, B, C and D solutions to them.                                                                                                                                 (/2)

Materials: List the equipment and chemicals/specimens you will be using to conduct the experiment. Always note any differences from the equipment you actually use and what is written in your text.

What we need for the lab is:

·      4 X 6 spot plate

·      Masking tape

·      Solutions A, B, C and D (Caution: Some of the solutions are corrosive.)

·      4 pieces of Mg ribbon

·      4 pieces of red litmus paper

·      4 pieces of blue litmus paper

·      Bromothymol blue solution

·      Indigo carmine solution

·      Methyl orange solution

                                                                                                                                          (/2)          

Procedure:

Include a brief outline of the steps to follow. If you are using the textbook you can simply record “Refer to text, page __”

1. First, read this entire procedure. Then, design a data table to record your results. Include a title for each column and row in your data table. Make sure your data table clearly indicates each solution you will be using and the indicator it will be mixed with. Give your data table a title.

2. Use masking tape to label the rows on your spot plate A, B, C, and D.

3. Add a few mL of Solution A to each of the six wells of row A of the spot plate. Place Solution B in the next six wells in row B. Repeat for Solution C and Solution D.

4. Place a piece of magnesium ribbon in the first well of each of the four rows.

5. Place red litmus in the second well of each row. Place blue litmus in the third wells of each row.

6. Add five drops of bromothymol blue solution to the fourth well of each row. Add five drops of indigo carmine solution to the fifth well. Add five drops of methyl orange solution to the sixth well.

7. Record your results in your data table. State the colour or other observations.

8. Your teacher may wish to see your spot plate once it is completed. Be sure to check before you begin clean up.

9. Clean up and put away the equipment you have used. Follow your teacher’s instructions for disposal of wastes.

“Refer to text, page 230”                                                                                           (/2)

Results: This is the section where you will record your data that you collect and observations from carrying out the experiment. This may be in the form of:

                                                            

·      a diagram


·      a short list of observations


·      a table of results


·      a graph etc

Mg Ribbon	Red Litmus	Blue Litmus	Bromothymol Blue	Indigo Carmine	Methyl Orange	Unknown
Grey and bubbles forming on Mg.	Is acid did not change colour.	Is a base so the litmus paper turned red.	Instant yellow/goldish	Did not change	Instant Red	A
Turned dark grey.	Turned blue	Turned blue	Instant blue	Instant dark green	Instant yellow/goldish	B
No change	Turned grey	Turned grey	Instant green	No change	No change	C
No change	Turned blue	Turned grey	Instant blue	Instant dark blue	No change	D

                                                                                                                                 (/4)

Discussion:

You will often be asked to answer some questions about your experiment. Your answers should be written in full sentences under this heading.

Analyze:

1. List the solutions in order from most acidic to least acidic (most basic).

The solutions from most acidic to most basic is indigo carmine, bromothymol blue and methyl orange.  

2. Which solution do you think was neutral? Explain how you know.

I think the indigo carmine was more neutral, because it did not change colour and it stayed its indicator colour blue. It changes colour when it is mixed with a higher base at 11.2. That big cap could make the solution neutral since the indicator stayed blue when it was mixed with an acid. It would of change if it was a actual base. The other indicators changed colour, but was bases before since they turned the colour of the indicator red and made them acids.

3. You used two bases. Explain how you know which solution was more alkaline (more basic).

I know, because on the colour change of the indicator chart for the solutions the bromothymol changes colour further down the column in the acids.

4. How can magnesium metal be used to distinguish between an acid and a base?

Well metal is a base since you need a metal and water to make an base and if you have water and a metal mixed with a acid and it changes well you know it is a base. If you mix it with a base then it will not change so you can distinguish between an acid and a base with a magnesium.

Conclude and Apply:

1.    (a) What colour would each of the five indicators be in a solution that is pH 3?

Red litmus= red

Blue Litmus=red

Bromothymol blue= yellow

Indigo carmine= blue

Methyl orange= red

(b) What colour would each of the five indicators be in a solution that is pH 10?

Red litmus= blue

Blue Litmus= blue

Bromothymol blue= blue

Indigo carmine= blue

Methyl orange= yellow

2.    Suppose you are asked to put together a test kit to determine whether water taken from a factory waste drain is acidic, basic, or neutral. Your kit can contain only three tests. Which tests would your kit contain? Explain.

Your kit probably would contain red and blue litmus paper and bromothymol blue, because if these change colours from what they were originally it will tell you if it is an acid or a base.

3.    Refer to the photo of the lichen Roccella tinctoria on this page, from which litmus is extracted. If this lichen were ground up and then soaked in vinegar, what colour would the solution likely be?

The solution would likely be white.

4.    What is the colour of seawater that has had bromothymol blue added to it?

The colour of seawater that has bromothymol blue in would more likely turn yellow.

5.    Consider the colour-coded map of the world’s oceans shown to the right. 


 (a) Which regions of the world’s oceans appear to be most affected by the drop in pH level?

   The drop in pH level has mostly affected the orange regions.


(b) Which regions are the least affected?

The drop in pH level has affected the light blue regions the least.

                                                                                                                              (/4)

Conclusion: Write a brief summary of your results and 2-5 sentences summarizing the key ideas learned from the experiment. The conclusion should link back to the original purpose. You should include possible sources of error and/or ideas to improve or expand your experiment next time.

Are results went well and successful since we follow the procedure. I learned from this experiment that pH indicators will react if they are in acidic and basic solutions. The indicators only changed if the indicator is the opposite either a acid or a base than the solution we are mixed the indicator with. One error we had was the blue litmus paper was not changing even though it was mixed with an acid, but that probably was because the litmus paper got mixed and was red. Next time we need to not mess up the materials and we need to handle our indicators or chemicals carefully, not having them spill.

                                                                                                                                 (/2)

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