Qualitative Analysis Essays - Analytical Chemistry, Precipitation

Qualitative Analysis Qualitative Analysis Introduction: Qualitative analysis is used in the determination of the identity of a substance. It is different from quantitative analysis, which deals with the determination of the amount of a substance. In this experiment, qualitative analysis techniques are used to determine whether or not a sample contains a certain ion. When using this method, an unknown and a reactant are mixed. The result of the reaction leads to a conclusion about the presence or absence of certain ions in the unknown. Many ions react in similar ways, and although the addition of one reagent to an unknown may not identify the ion, it limits the possibilities as to what the ion could be. A sequence of reactions used to analyze a sample is called a scheme, and it usually requires a large number of reagents and separation steps. For this experiment, the unknown may contain anywhere from 2 to all of the following cations and anions: Cations Anions Ag+ Cl- Ba2+ SO42- Fe3+ PO43- Cu2+ Cr3+ The following reagents are used to identify the ions: 1M H2SO4 2M HCl 2M NH4OH (labeled as NH4+) 2M NaOH .1M Ba(NO3)2 (labeled as .1M Ba2+) .1M AgNO3 (labeled as .1M Ag+) The first four are used to identify the cations, and the last two, used in conjunction with the first four, are used to identify the anions. The identification of the ions is mainly based on solubilities. This means that something must be known about the solubility characteristics of the different ions in the presence of the available reagents. The point of the first part of the experiment is to learn which reagents cause the ions to form precipitates, and which reagents dissolve the precipitates formed by the ions. This information is used to make the flow charts for the identification on the unknown ions. For example, it is important to know that a certain reagent will dissolve the precipitate formed by one ion, while it will not dissolve the precipitate formed by another ion. This can be used to distinguish between two different precipitates present in a solution, or to confirm which ion formed the precipitate and therefore was present in the solution. When carrying out the reactions, avoid adding an excess of reagent to the solution. This is because some precipitates redissolve in an excess of the reagent. Therefore, in cases where one drop of reagent produces a precipitate, 3 or more drops could completely dissolve the precipitate without it ever being visible to the eye. This would cause a large error in the scheme developed to identify the unknown ions. Experimental: The first part of the experiment consists of reacting the cations and anions with the reagents in order to see what the reaction will result in (precipitate or no precipitate). The cations were each reacted with the first four reagents listed in the introduction (H2SO4, HCl, NH4+, and NaOH). Then, the anions were each reacted with Ba2+ and Ag+. This was done by placing 2 drops of the ion in the test tube and then adding 2 drops of reagent. Each cation was reacted with each of the 4 reagents before moving on to the next cation to be tested. Prior to performing the reactions, a chart was made like the one in the data and calculations section. As each reaction was performed, the chart was filled in with the observation of what happened. If there was no change, NR was written in the chart for ?no reaction.? If a precipitate formed, the color of the precipitate was written in the chart. If there was no precipitate but there was a color change in the solution, that was also recorded. As each reaction was carried out, it was sometimes difficult to determine whether a precipitate formed or not. If there was uncertainty, the test tubes had to be placed into the centrifuge in order to separate the precipitates from the solution. There are some very important things to remember when using the centrifuge. First, when tubes are placed in the centrifuge, a tube with an approximately equal volume of solution should be placed exactly opposite each sample tube to counterbalance it (use a test tube filled with an equivalent amount of water if necessary). Second, the centrifuge should come to a stop before it is opened and the test

Today I Choose Me Professor Ramos Blog

Today I Choose Me Apart of love is wondering where you belong and where you fit in. Sometimes that is looking for love in the places we think are right for us and it could be us looking in the wrong places. What attracts us to someone? Is it in the tone of their voice when we listen to them speak? The feeling of their touch the minute they lay a single hand on you? Is it how their laugh makes you smile? Or is it them introducing you to the most important people in their life? We never truly know what it is that a person may see in us that makes them attracted to us. Because we dont truly know these things it often leads us to insecurities, depression, self-doubt, and sometimes death. In â€Å"Bien Pretty† by Sandra Cisneros, Lupe points out â€Å"What kills me is your silence. So certain, so solid. Not a note, nor postcard. Not a phone call, no number I could reach you at. No address I could write to. Neither yes nor no. Just the void. The days raw and wide as this drought-blue sky. Just the n othingness. That’s what hurts† (Cisneros 157). A man that she fell in love with just vanished as if everything they done was meaningless. Lupe was devastated and heartbroken when Flavio left, it took her weeks to pull herself up from this pain. During the time that Flavio was modeling for Lupe they began telling stories about each others lives. â€Å"What I liked best about working with Flavio were the stories† (Cisneros 148). How could this poor Mexican man that had very little take so much from her? Lupe began looking at Flavio a different way, she then imagined how â€Å"With skin sweet as burnt-milk candy, smooth as river water. He made you bien pretty even if I didn’t always know it. Yes he did† (Cisneros 152). Would that have been love for Lupe or was she just feeling that way because of the time they spent together? Lupe begins to ask herself â€Å"What’s happened to me? Flavio was just Flavio, a man I wouldn’t’ve looked at twice before† (Cisneros154). Everything around Lupe would remind her of all the little things of Flavio, In the beginning of the story Lupe points out â€Å"I’m to blame. Flavio Munguia was just an ordinary Flavio until he met me†¦ On ce you tell a man he’s pretty, there’s no taking it back† (Cisneros 137). Lupe chose to believe that she was the reason for Flavio being the way he was, that she turned him into this man that was selfish. After the ongoing relationship that Flavio and Lupe had, the truth was finally spoken. Flavio told Lupe that he had to go back to Mexico to take care of things back home. However, never once did he tell Lupe that he had children from another marriage. By the pain that Lupe was in the only words that could come out â€Å"I think you better go now. I gotta get my clothes out of the dryer before they get wrinkled† (Cisneros 157). Lupe tried to find peace, but because she was still broken all she could think of was anger and how much she wanted to hurt Flavio for hurting her. All that time you spend getting to know someone, loving their insecurities, and loving their biggest flaws for them to just hurt you and leave. Lupe was blinded by Flavio’s love that she forgot who she was. â€Å" Just the way I use to believe I was pretty. Before Flavio Munguia wore all my prettiness away† (Cisneros 137). Everything Lupe felt had turned away and made her feel less, â€Å" When I look in the mirror, Im ugly. How come I never noticed before?†(Cisneros 160). Lupe was in pain. Flavio made her feel like she was the weak one. She was too busy trying to make him feel special she forgot about her own self-worth. To The Girls Who Need To Love Themselves by Madison Sonnier writer from Thought Catalog, explains â€Å"I understand how you must be feeling – desperate for closure, envious of those living a fulfilling single life and loving it, and clueless about where to start on your journey to letting go of the person who haunts you and has consistently failed to give your rare and beautiful heart what it needs.† Lupe regretted two things; not telling Flavio she was in love with him and to ask for forgiveness. Lupe didn’t know what was going to happen next, what she did know was that this would be the last feeling he took from her. It took weeks before Lupe could pick herself back up, she would avoid going to work, painting, and being out in public. Lupe grabbed everything of Flavio and burned them â€Å" I didn’t expect paper to take so long to burn, but it was a lot of layers† (Cisneros 160-161). Later during that time Lupe sat herself in front of a t.v watching a telenovela show where she was then inspired. She would think of the words from Daniela Romo singing â€Å" Ya no. Es verdad que te adoro, pero mas me adoro yo† (I love you, honey, but I love me more)(Cisneros 163). Lupe was done feeling sorry for herself, she picked herself up and remembered who she was. She took a hold of her life, â€Å" The First Step† by Najwa Zebian states â€Å"In order to achieve greatness, you have to be willing to take the right steps towards it† (113). And that is exactly what Lupe chose to do, she chose to take her life back. â€Å"Everywhere I go, It’s me and me. Half of me liv ing my life, the other half watching me live it† ( Cisneros 163). Instead of hurting Flavio any way that she could have Lupe guided herself through the pain and turned it into something greater. We all want to know what it is that makes us feel as much pain when getting hurt. â€Å" Sexology† by Samuel Aun Weor writes â€Å" When human beings are truly in love, they become intuitive, mystical. In such moments they forebode their future, afraid of what might happen to them† (4). Lupe was in love with a man that she didn’t at first even see herself with or even would have noticed him. Even with all the stories they shared with each other, there could have been moments he could have told her the truth. Was it fear of losing her? Or was it that he took advantage of her? We aren’t sure why people don’t always speak up and just really say how they feel. We end up being the ones who are clueless. Lupe could have given up and let Flavio ruin her life, but she chose to become a strong woman and choose her. Love is costful, sometimes that is taking all of someone’s love or worse, someone can go beyond just being depressed but hurting themselve s or another. Love is complicated. Love is beyond us. But it does not take away who we are. Cisneros, Sandra. Woman Hollering Creek and other stories. New York, Vintage, 1991. â€Å"To The Girls Who Need To Learn To Love Themselves First.† Thought Catalog, 25 Dec. 2016, thoughtcatalog.com/madison-sonnier/2016/05/to-the-girls-who-need-to-learn-to-love-themselves-first/. WEOR, SAMAEL AUN. SEXOLOGY: the Basis of Endocrinology and Criminology. GLORIAN PUB, 2016. Zebian, Najwa. Mind Platter. Andrews McMeel Publishing, 2018.