Complexometric Determination of Water Hardness Essay Example for Free

Complexometric Determination of Water Hardness Essay Abstract: Using complexometric method of calculating water hardness, an EDTA solution was made and calculated to be around .00209M. This EDTA solution was then used to titrate a water sample with unknown hardness. The sample used was sample #18. The hardness of the sample was calculated to be 180505 ppm. This is within normal levels for the Mesa area. Introduction: This experiment focuses on titration with EDTA. Titration is the determination of a given component in solution by addition of a liquid reagent of known strength until the endpoint is reached when the component has been consumed by reaction with the reagent. An indicator called Eriochrome Black T will enable detection when the EDTA has completely chelated the metal impurities. Chelation happens when a ligand (with more than one binding site) forms a complex with a metal ion. Ligands are complexes that form when the electron donating groups form coordinate covalent bonds through empty orbitals on the metal ion. This experiment contains Ammonium chloride buffer which is an inhalation irritant. Procedure: About 500 mL of approximately 0.004 M disodium EDTA solution needed. The solution should have between 0.7–0.8 g of Na2EDTA and dissolve in about 500Â  mL deionized water in a plastic bottle. The bottled is Sealed and shaken vigorously for a few minutes to dissolve the salt. Standardize the Na2EDTA solution using a stock calcium ion solution as the primary standard. Using a 10-mL transfer pipet to add 10.00 mL of standardized calcium ion stock solution (1.000 g CaCO3/L solution) to a 250-mL Erlenmeyer flask which will have an additional 30 ml of deionized water to this titration flask. Adding a magnetic stir-bar the solution was then stirred. about 3 mL of ammonia/ammonium chloride buffer is added to the solution. Just prior to titrating the flask, adding four drops of Eriochrome Black T indicator solution will be needed. At the endpoint, the color will change from pink to violet to blue. This will repeat two more times. Then Choose one prepared unknown water sample as provided. Record the unknown code in a notebook, then titrate this water sample with your standardized disodium EDTA solution. Transferring 25.00 mL of the prepared water sample to a 250-mL Erlenmeyer flask will be done. Then Add about 20 ml of DI water to the titration flask, which will have a magnetic stir-bar. The solution will have an added portion of 3 mL of ammonia/ammonium chloride buffer. The solution will then change color as previously examined in the first portion. This procedure will be repeated twice more. Results and Discussion: EDTA solution Initial Reading (mL) (mL) delivered 0.0mL 50.01mL 0.0mL 47.05mL 0.0mL 46.10mL The average of the mL delivered of the three results is 47.72 mL The Molarity of the EDTA solution was calculated and is shown below. Ppt: 15.99 for 50.01 mL delivered Ppt: 4.68 for 47.05 mL delivered Ppt: 11.31 for 46.10 mL delivered Unknown solution Initial Reading(mL) (mL) delivered 0.0mL 22.9mL 0.0mL 21.41mL 0.0mL 20.41mL The average of the mL delivered of the three results is 21.57 The hardness of the unknown water sample was calculated using the Molarity of the EDTA solution standardized in the first portion of the lab. The calculation is shown below. Ppt: 20.55 for 22.9 mL delivered Ppt: 2.47 for 21.41 mL delivered Ppt: 17.92 for 20.41 mL delivered The tables reveal a difference in (mL) delivered in comparing the first experiment to the unknown. The unknown must have a weaker tolerance to the indicator in which the first experiment is stronger. Conclusion: The water hardness in Mesa ranges from 12 gpg (grains per gallon) to 22 gpg (1). The Ppt of the unknown and EDTA do and don’t fall within Mesa’s range. There are some numbers that fall within the range and there are some that may fall out. Overall the data has some proof that the water hardness of the EDTA and unknown can potential match up to Mesa’s. Sources: (1) http://www.mesaaz.gov/water/hard_water.aspx

Atrocities in Staffords Traveling Through the Dark Essay -- Traveling

Atrocities in Stafford's Traveling Through the Dark Is a drive just a drive, or is it a metaphor that imparts appreciation for life's fragility while simultaneously lamenting man's inability to appropriately confront, or understand, death? William Stafford's "Traveling Through the Dark" illustrates the mechanisms by which seemingly mundane events become probes into the mystery and ambiguity of the human condition. The poem's situation is simple, a lone traveler driving along a desolate canyon road spots a felled deer; the traveler, desiring neither to hit the deer, nor by swerving to avoid it, hurtle his car over the canyon precipice, stops his vehicle and proceeds to push the fallen animal over the canyon face, into the river below. As the driver struggles to displace the cold, stiff deer corpse he senses warmth emanating from its abdomen, it's an unborn fawn. Realizing that life remains in the body he had assumed dead, the traveler hesitates. Finally, he pushes the deer, one dead and the other not yet alive, off the road and into the chasm. While the poem's situation is simple, its theme is not. Stafford appears to be intimating that life is precious and fragile; however, nothing so clearly discloses these attributes of life as confrontation with death. Furthermore, the very confrontations that engender appreciation of life's delicacies force action-all to frequently callous action. Hence, the poem's tone contains elements of remorse as well as impassivity. The traveler's detached description of the mother, "...a doe, a recent killing; / she had stiffened already, almost cold" (6-7), and the wistful detail with which he depicts her unborn offspring, "...her fawn lay there waiting... ...iver. Because the deer's killer was a man behind the wheel of an automobile the traveler shares some relation with him. The traveler's anguish, his "bleeding", is the realization that he is implicated in the murder of the deer through his association to the actual killer. If expanded further, this metaphor can be applied to the entire human experience. All humanity is like a traveler driving through the dark. At varying junctions in our experiences we are, inevitably, both the discoverers and perpetrators of atrocities; the confusion surrounding our responses to theses junctions is the darkness we travel through. Stafford ends the poem after the traveler pushes the deer into the canyon's depths. We don't need to be told he returns to his car and drives on, we know it intrinsically, it's what each of us would have done, what each of us must do.

Athlete Classification

Athletes: the Good, the Bad, and the Ugly As a casual reader of the sports section of this newspaper, you come across many articles depicting the triumphs of local athletes. However, very rarely do these articles describe the actual athlete behind the success. Athletes come in all sorts of sizes and shapes. They range from the incredibly talented to the horribly uncoordinated. Some are great teammates while others would rather be a one man team. Certain athletes seek out attention from the people around them while others are modest and stay in the background.The fact of the matter is that there is a wide spectrum of different types of athletes that exist in this world and no two athletes are exactly the same. However, each can be put into one of nine general categories that they best fit. General Paton: the athlete who stands out as the captain of the team by helping their fellow teammates and managing their team. They are a well-rounded athlete, fairly skilled at their sport, but mo re importantly excellent at inspiring their team to perform to the best of their ability. This athlete is the backbone of the team and without them chaos could quite easily break out.The other athletes look up to this leader and follow their orders. When your team is losing, the leader is the one who gets everyone together and says things like â€Å"We can still win this† and â€Å"Don’t give up yet, we’re still in this one†. You can expect to see these athletes to do great things in their sports careers and in their regular lives. Effort King/Queen: the athlete who is known for doing everything they can to improve their game, from staying after practice to do extra to going to the gym every day before practice to workout. They are extremely motivated, determined and dedicated to what they do.These athletes are the ones that coaches very much want to be on their team. These players are known for being highly beneficial not only to the team’s succes s, but also to the other players around them. They set a great example for others around them and can leave a lasting mark on people. They may be referred to as a â€Å"gym rat†, but don’t think that’d a bad thing because when it comes to game time, don’t be surprised if they outperform the opposing team’s â€Å"star† player. The Natural: the athlete who was given the gift of natural athleticism. They are known as the â€Å"MVP† of their team.Most often, they are three sport athletes who do pretty well in each. They don’t have to work as hard as others to be able to have relative success as they are often naturally strong and talented. Many other people loathe these athletes because they have all the tools they need to succeed. There is no guarantee that these athletes will be good teammates or have good work ethic, but coaches can be assured that these people are a great place to build upon and make a team around. The Anti-ath lete: the athlete who was not given much natural ability. They are weak, uncoordinated, and clumsy.They can get by playing some sports, but they have limited options as most sports require decent athletes at a competitive level. They are the â€Å"benchwarmer† of teams, the weak link in the chain. Other athletes get easily frustrated with these players when they make mistakes even though it may not be entirely their fault. Although their athletic output may not be as high as some would like, no one can question their effort and dedication. They play sports not because they are good at them, but because they truly love them, and in some cases, that can bring someone further than natural talent. Timmy/Tina Tries Too Much†: the athlete who â€Å"overworks† and goes beyond what’s necessary in unimportant situations. Everyone has seen at least one of this type of person before, whether they know it or not. The most common place to find these types of people is in gym class. They are the ones that you see coming to every class and trying as hard as they can to win. Many people don’t like these people too much because they exert themselves in unnecessary situations. Many times, these people develop a poor reputation as a â€Å"try hard† among their friends.They may not be the most talented person there, but you can always count on seeing them breaking a sweat. â€Å"Sammy/Susie Suck up†: the athlete who does everything they can to suck up to their coach. They try to get all the brownie points they can in hopes of getting more playing time. They follow all directions given by their coach, they help out whenever possible, and they give full effort when the coach is looking. They are very similar to a teacher’s pet that you would most commonly find in elementary school. Much like the other students find these eacher’s pets to be annoying, a coach’s pet’s teammates often think that these people a re annoying and not fun to be around. â€Å"The Tornado†: the athlete who is overly aggressive when playing sports. They are known to push other players around and often get in trouble with the ref. Also, they are a coach’s nightmare as they are hard to control. The athletes aren’t always good to have on a team because they give the team a bad reputation and make it seem as though everyone on the team plays like they do. Also, they are much more prone to being benched and as a consequence, letting the rest of the team down.Many times, other athletes don’t like participating with people like this because these aggressive people take the fun out of competition. .The Crowd Pleaser: the athlete who likes to show off in front of their fans. They wear the flashy equipment, they perform the crazy stunts, and they are the cocky personality in the locker room. To give you a clear picture of this kind of athlete, just imagine the player that has the best gear, the flashiest jersey, performs the â€Å"coolest† moves, and seems to put on a show for their â€Å"fans†.It isn’t uncommon for their teammates to call them a â€Å"show boat† right to their face. But that doesn’t stop them from doing what they do best because they thrive on the attention. Garbage Can: the athlete who throws away their athletic abilities and coasts. They are lazy, unmotivated, and not dedicated at all. They may be one of the best athletes around but they don’t apply their abilities. Everyone knows at least one person who completely wastes the natural talent that was given to them.It’s a shame to see these athletes waste talent when there are other athletes with considerably less talent who work twice as hard. Many people don’t like these athletes because they take their abilities for granted and don’t realize that half of the battle towards being successful in a sport has already been fought for them. All th ey need to do is put in just the slightest bit of effort and they will start to see considerable success. In most cases, these athletes are looked down on by others and carry a negative connotation with them everywhere they go.There is a lot more to a team’s success than just the wins. The players involved are what really define a team and they ultimately determine how successful a team can be. You don’t always need a team full of superstars to win. This is where many sports coaches go wrong. They think they can build a championship caliber team from a bunch of players that would rather prove they are good than their team. It’s important to remember that it takes the right combination of these nine types of athletes to make the perfect team.

How to Write a Personal Narrative

The personal narrative essay can be the most enjoyable type of assignment to write because it  provides you with  an opportunity  to share a meaningful event from your life.  After all, how often do you get to tell funny stories or brag about a great experience and receive school credit for it? Think of a Memorable Event   A personal narrative can focus on any event, whether it is one that lasted  a few seconds or spanned  a few years. Your topic can reflect your personality, or it can reveal an event that shaped your outlook and opinions. Your story should have a clear point. If nothing comes to mind, try one of these examples:   A learning experience that challenged and changed you;A new discovery that came about in an interesting way;Something funny that happened to you  or your family;A lesson you learned the hard way. Planning Your Narrative Start this process with a brainstorming session,  taking a few moments to scribble  down several memorable events from your life. Remember, this doesn’t have to be high drama: Your event could be anything from blowing your first bubble gum bubble to getting lost in the woods. If you think your life doesnt have that many interesting events, try to come up with one or more examples for  each of the following: Times you laughed the hardestTimes you felt sorry for your actionsPainful memoriesTimes you were surprisedScariest moments Next, look over your  list of events and narrow your choices by selecting those that have a clear chronological pattern, and those that would enable you to use colorful, entertaining, or interesting details and descriptions.   Finally, decide if your topic has a point. A funny story might represent irony in life or a lesson learned in a comical way; a scary story might demonstrate how you learned from a mistake.  Decide on the point of your final topic and keep it in mind as you write. Show, Don’t Tell   Your story should be written in the first-person point of view. In a narrative, the writer is the storyteller, so you can write this through your own eyes and ears. Make the reader experience what you experienced—not just  read what you experienced. Do this by imagining that you are reliving your event. As you think about your story, describe on paper what you see, hear, smell, and feel, as follows: Describing Actions Dont say: My sister ran off. Instead, say: My sister jumped a foot in the air and disappeared behind the closest tree. Describing Moods Dont say: Everyone felt on edge. Instead, say: We were all afraid to breathe. Nobody made a sound. Elements to Include Write your story in chronological order. Make a brief outline showing the sequence of events before you begin to write the narrative. This will keep you on track. Your story should include the following: Characters: Who are the people involved in your story? What are their significant character traits? Tense: Your story already happened, so, generally, write in the past tense. Some writers are effective in telling stories in the present tense—but that usually isnt a good idea. Voice: Are you attempting to be funny, somber, or serious? Are you telling the story of your 5-year-old self? Conflict: Any good story should have a conflict, which can come in many forms. Conflict can be between you and your neighbor’s dog, or it can be two feelings you are experiencing at one time, like guilt versus the need to be popular. Descriptive language: Make an effort to broaden your vocabulary and use expressions, techniques, and words that you don’t normally use. This will make your paper more entertaining and interesting, and it will make you a better writer. Your main point: The story you write should come to a satisfying or interesting end. Do not attempt to describe an obvious lesson  directly—it should come from observations and discoveries. Dont say: I learned not to make judgments about people based on their appearances. Instead, say: Maybe the next time I bump into an elderly lady  with greenish skin and a large, crooked nose, Ill greet her with a smile. Even if she is clutching  a warped and twisted  broomstick.