Lab 20B Reflection

Part 1.

I was able to rank the strength of unknown acids and indicators pretty easily. Firstly, I had to determine what the unknown indicators were. Using the chart I knew the indicators used in the lab were, Bromcresol Green, Bromthymol Blue, Indigo Carmine, Orange IV, and Thymolphthalein. Using the results from the lab I could easily determine three of the five indicators. For example, I could tell which indicator was indicator was Indigo Carmine because it was the only one of the mystery indicators that went from a blue acid to a yellow base. The two unknown indicators that were more difficult to find were Bb and Bg, because they both went from a yellow acid to a blue base. However, I could differentiate them as they had different ranges at which they change colour.
Now that I knew the identities of all the unknown indicators I could begin to find the strength of of the unknown acids. For each acid I found out which pH they had to be determined by what colour they turned in each indicator. For example, for acid 2 I saw it turned yellow in Bb therefore the pH strength had to be less than or equal to 6, in Orange IV it turned yellow so the pH had to be greater than or equal to 3. Acid 2 turned colourless in Thy, so it had to be less than or equal to 9, it turned blue in Bg, therefore it had to be greater than or equal to 6. It turned blue in Indigo Carmine so the pH had to be less than or equal to 11. Using all of this data I could determine that the pH of acid 2 was exactly 6. Since there had to be only whole numbered pH’s and it had to be less than or equal to 6 and greater than or equal to 6, the pH could only be 6. I used this method of finding pH levels for all of the unknown acids.
I used the pH ranges of the indicators from the data booklet to rank all of the acids and indicators by their pH’s and pH ranges.

Part 2.

 I can analyze and make judgments about a process.
This was shown when I was able to analyze the colours of acids and indicators to determine the pH levels of all the unknown acids and indicators.

I can communicate with others with intention and purpose.
I demonstrated this when I helped a few classmates by teaching them my method of determining pH levels of the unknown acids. I went over the method with them and watched them do an example to make sure they understood my method.

Lab 19C- Self-Assessment

Core Competency Thinking.

I demonstrated my knowledge of the thinking core competency during Lab-19C. For example, I can analyze evidence to make judgements. I was able to determine which solutions produced a precipitate when mixed together, by analyzing the appearance of the mixed solutions. I also showed my ability to use the thinking core competency when I had to judge whether or not the precipitates in the test tubes had disappeared when heating the tubes. I analyzed the evidence to determine at which temperature the precipitates would dissolve.