Acid Base Indicator Lab Revised

Conclusion: This experiment investigated how you can tell between an acid and a base In order to study the problem we need to find out how the chemicals change in the indicators Results showed that the indicators really work to find out what you need to find like witch ones an acid or a base Questions about the experiment include . Finally, Possible errors in this lab could have occurred when . If the experiment was repeated, some changes to improve the experimental design could be . 1. 2. 3. 4. 5. 6. Place one small piece of blue litmus paper into one microwell. Place one small piece of magnesium into one microwell. Add 5 drops of Unknown A into each microwell containing an indicator. Record your results in Table 2. Repeat steps 1 – 5 for Unknown B – H. Wash and dry your microplate. 1. Place one small piece of blue litmus paper into one microwell. Observations: Table 1: Acid and Base: Indicator Observations Phenolphthalein Acid 0.1 M HCl Stayed the same Base 0.1M NaOH Pinkish purple Bromothymol blue Changed to a different shade of blue Stayed blue Methyl orange Changed to a pink colour Stayed the same Red litmus Turned white Turned blue Blue litmus It turned pink Turned white Magnesium metal Turned the liquid yellow and shrunk Didn’t do much Table 2: Identifying Unknowns and House Hold Solutions Indicator A Didn’t Phenolphthalein No change pink Observations D Oven Cleaner nothing pink diluted Brighter yellow B C Lemon Juice Nothing Milk of Magnesia pink Cola nothing yellow Lighter yellow change Turned from teal Bromothymol blue to pale yellow Changed to red Methyl orange blue Stayed Stayed orange orange Lighter blue blue Turned red yellow red yellow red Red litmus No change No change blue No change blue nothing blue No change Blue litmus Turned red No change Blue red nothing red nothing red Rusted a Dark on bubbling nothing Smells like nothing nothing base acid Magnesium metal Nothing bit Acid, Base or Neutral? the edge Neutral acid Base rotten egg acid base acid 1) List the unknown solutions in order from most acidic to least acidic (most basic) A, D, C, B 2) Which unknown solutions was neutral? Explain how you know. It was water because nothing changed 3) You used two acids. Explain how you know which solution was more acdic. D was more basic A created more bubbles and gasses 4) Which acid/base indicator do you think would be the most useful? Explain. The Phenolphthalein because if it’s a base it turns pink and if it’s a acid its colourless 5) Which acid/base indicator do you think would be the least useful? Explain. The magnesium strip was the least useful because there was no real results 6) If you add a clear unknown solution to phenolphthalein and it remains clear, what are two possibilities for the pH of the solution? Very acidic or not or a weak base 7) If you add a clear unknown solution to bromothymol blue and it stays blue what are two possibilities? It’s a base or a very weak acid 8) Suppose you were asked to put together a test kits to determine whether water taken from a factory waste drain is acidic, basic or neutral. Your kit can only contain three tests. Which tests would your kit contain? Explain. Litmus paper would be the most useful Phenolphthalein would be pretty useful because if it’s an acid it would stay clear and if it is a base it will turn very pink and bromothymol blue because it’s pretty much 50/50 Acid Base Lab – Self assess prior to handing in Just starting out… In Progress Observations Completion/ Questions Conclusion / Reflection / Big Ideas Getting there check Got it Rock Star  Data tables are completed. All data is clearly recorded  Ideas demonstrate thoughtful thinking  All questions are complete and well-explained check check  Student shows exceptional ability to sum up the big ideas of the lab activity  Student can describe the purpose and specifically report his/her findings  Detailed yet concise  Student has demonstrated reflection on the activity, addresses possible errors made during lab activity and improvements for future tests