Analysis of two brands of commercial Bleaches Essay Example for Free

Analysis of two brands of commercial Bleaches Essay Analysis of Two Brands of Commercial Bleaches Objective To determine the concentration of sodium chlorate(I) (NaClO) in two commercial bleaches and compare the two bleaches on both concentration and price. Procedures 1. 10. 0 cm3 of the bleach KAO was pipetted into a clean 250 cm3 volumetric flask. It was made up to the mark using deionized water. 2. 25. 0 cm3 of the diluted solution was pipetted into a conical flask. 3. 10 cm3 of 1 M potassium iodide solution and 10 cm3 of dilute sulphuric acid was added into the conical flask also. 4. The mixture in the conical flask was titrated against the 0. 0992 M sodium thiosulphate solution. 5. Three drops of freshly prepared starch indicator are added into the conical flask when the reaction mixture turned pale yellow . 6. The mixture was titrated to the end-point. 7. At the end point, the solution turned from dark blue to colourless. 8. Steps (1) to (7) were repeated with another bleach LION Results Concentration of standard sodium thiosulphate solution : 0. 0992M Brand 1 Trade Name : KAO Bleach Price : $7. 33per dm3 ($11/1500mL). Trial 1 2 Final burette reading / cm311. 90 23. 40 35. 00 Initial burette reading / cm3 0. 20 11. 90 23. 40 Volume of Na2S2O3 / cm3 11. 70 11. 50 11. 60 Brand 2 Trade Name : LION Price : $6. 67per dm3 ($10/1500mL) Trial 1 2 Final burette reading / cm3 14. 60 28. 70 42. 80 Initial burette reading / cm3 0. 50 14. 60 28. 70 Volume of Na2S2O3 / cm3 14. 10 14. 10 14. 10 Questions 1. For each brand, calculate (a) the amount of the active ingredient available in g dm-3. (b) the cost per gram of this compound. (c) 1a) For KAO Bleach, Averge volume of sodium thiosulphate solution used=(11. 5+11. 6)/2=11. 55cm3?no. of mole of S2O32-=(11. 55/1000)(0. 0992) =0. 00114576mol. ?no. of mole of I2 =(no. of mole of S2O32- )/2 =0. 00057288mol ?no. of mole of OCl- in10 cm3 solution = no. of mole of I2 x10 =0. 0005728810 =0. 0057288mol ? Mass of OCl- contained in 10 cm3 solution=0. 0057288x(16+35. 45) =0. 29474676g ?Concentration of OCl- (active ingredient available) =0. 29474676/(10/1000)=29. 47gdm-3 For LION Bleach, Averge volume of sodium thiosulphate solution used=(14. 1+14. 1)/2=14. 10cm3 ?no. of mole of S2O32-=(14. 10/1000)(0. 0992) =0. 00139872mol. ?no. of mole of I2 =(no.of mole of S2O32- )/2 =0. 00069936mol ?no. of mole of OCl- in10 cm3 solution = no. of mole of I2 x10 =0. 0006993610 =0. 0069936mol ? Mass of OCl- contained in 10 cm3 solution=0. 0069936x(16+35. 45) =0. 35982072g ?Concentration of OCl- (active ingredient available) =0. 35982072/(10/1000)=35. 98gdm-3 1b)For KAO Bleach, Cost per one gram of OCl- = 11 /[29. 474676x(1500/1000)] =$0. 277/g For LION Bleach, Cost per one gram of OCl- = 10 /[35. 982072x(1500/1000)] =$0. 185/g 2. Based on the calculated results, decide which of the two brands of bleach is a better buy. When compring the costs per one gram of OCl- of KAO(0. 277/g) and LION($0. 185/g), as we can pay a lower price ($0. 185)to buy the same weight of active ingredient (OCl- ) in LION bleach, LION bleach is a better buy. 3. Explain why potassium iodide and sulphuric acid must be in excess. ClO-(aq) + 2I-(aq) + 2H+(aq) i I2(aq) + H2O(l) + Cl-(aq) From the equation above, iodide ions and hydrogen ions react with Hypochlorite ions to form iodine ,water and chloride ions. To determine the actual number of mole of ClO- ,all ClO- ions sholud react to give iodine. KI (I-) and H2SO4 (H+) must be in excess to ensure all ClO- has been converted into Cl- ions. Then the number of mole of I2 produced is calculated by titrating against sodium thiosulphate and hence the number of mole of ClO- ions can be calculated by ratio: No. of moles of ClO- = No. of moles of I2 In other words, excess potassium iodide and sulphuric acid are used for ensuring all ClO- ions are reacted react to give iodine. Moreover,dilute sulphuric acid is added to increase the rate of reaction. If KI and H2SO4 are not in excess, some of the ClO- ions are not converted into Cl- . Consequently the calculated number of mole of ClO- ions present would be smaller than the actual one since the number of mole of ClO- ions which are not converted into Cl- are not taken into account. 4. Bleaching solution may deteriorate for two main reasons. One is the attack by carbon dioxide in air according to the equation: 2ClO-(aq) + CO2(aq) i CO32-(aq) + Cl2(aq) What is the other possible reason? Under normal condition,Hypochlorite ions decompose to give oxygen and chloride ions. Ionic equation: ClO-(aq) i O2(g) + 2Cl-(aq) Chemical equation: NaClO(aq) i O2(g) + 2NaCl(aq). The rate of the reaction above can been increased at high temperature or under sunlight. When sodium hypochlorite is heated or evaporated, sodium chlorate and sodium chloride will be formed. Chemical equation: 3 NaOCl(aq) i NaClO3 (aq)+ 2 NaCl(aq) 5. The starch indicator should not be added too early. Why? Starch is often used in chemistry as an indicator for redox titrations where iodine is present as starch forms a very dark blue-black complex with iodine. Moreover,the indicator is not affected by the presence of iodide (I-). In order for the the starch solution to change colour, both starch and iodide must be present. Starch forms an unstable complex which is blue coloured in low concentrations of iodine. However, this complex is in high concentrations of iodine . If starch solution is added too early, the conical flask still contains high concentration of iodine. As a result, highly stable complex is formed,the starch indicator then cannot be decolourised and the complex will spoil the reaction medium. Consequently, the titration cannot continue. Therefore the iodine must be diluted first with the titrant ,sodium thiosulphate to ensure no higly stable complex is formed. After that the starch can be added.

Hegels Phenomenology of Spirit, Ecos The Myth of Superman, and CamusThe Fall :: Phenomenology Dialectical Essays

Hegel's Phenomenology of Spirit, Eco's The Myth of Superman, and Camus'The Fall    It is impossible to truly realize the impact of earlier minds on modern society, simply because that which they taught is so intrinsic to thought which followed. One great example is G.W.F. Hegel, an eighteenth-century philosopher who first named dialectical relationships. In his book Phenomenology of Spirit, Hegel details the relations between people and ideas in a way that now seems obvious, but was groundbreaking at the time. He opens his discussion by describing consciousness meeting as master and slave, and describes the development of the interaction in a dialectical fashion. In this particular situation, the slave receives an original definition from the master, then negates it, since it is not a complete (and therefore an inaccurate) description of the self. The relationship between the two consciousness plays out as a progression of a definition, the negation and the result. The common terms given to this movement are thesis (the original posit or definition), antithesis (th e negation), and synthesis (the final movement combining elements of each of the first two). The synthesis often becomes the new thesis, which is similarly negated. The whole theory can be seen as an elaboration of cause and effect, where the original thesis "causes" the antithesis which "causes" a synthesis. There is a direct causal progression. An interesting concept which the dialectic gives rise to is the fact that once a thesis is made everything that comes after is affected by the original posit. For example, one can attempt to negate a label, yet still give validity to the label, and the synthesis will cause the slave, even in the "free" definition, to define the self in terms of what the master originally defined. Even a negation ends in the original terms, because the original terms were the "cause" of any definition the slave would create. Hegel's theory held prevalence in society for many years, thinkers such as Kierkegaard and Heidegger relying heavily upon the dialectic as a way to further their own theories. Cause and effect became the main way of looking at world events, and life continued until the advent of the twentieth century, which saw a negation of Hegel's thought and a shift in the dialectic. In 1972, an English translation of Umberto Eco's The Myth of Superman was published. In this article, Eco, a critic and novelist, discussed the shift from the Hegelian dialectic in light of the Superman saga.

Face to face communication Essay

Nothing can replace the value of face-to-face communication. However in a growing business, traveling to meet with customers and team members is not always feasible or economical. We communicate over email and phone, but even then, messages get misinterpreted and a sense of personal connection is never truly established or maintained. In fact, it’s said that over 90% of how we communicate is through nonverbal cues like gestures and facial expressions. With that said, one cannot underestimate the power of video conferencing to enable businesses to maximize the effectiveness of their communications. Here are just some of the many advantages of face-to-face communication. Effectiveness of meetings: Things get done. When there’s an issue that requires a decision, you’re able to reach a consensus more quickly. One simple 5 minute conversation could eliminate 15 back and forth emails. When there are many people in a meeting, there’s more energy and opportunities to participate and creatively contribute. Oftentimes there’s also a synergy that’s achieved which ignites discussion and innovative thinking. You can brainstorm more easily and solve a handful of problems. Read more: Reasons why people communicate  essay Nonverbal communication: Reacting and adjusting to nonverbal cues. Someone who is frequently checking their watch or yawning, would tell you very easily that it’s time to wrap things up or make an effort to change the quality of your voice to be more engaging (or at least change the subject. ) And the very opposite is also true; if colleagues are smiling, nodding or leaning forward, you know that they’re invested and have their buy-in. There isn’t much guesswork involved. A personal touch: Plain and simple, it’s just nice. There’s a feeling of community because we’re better able to socialize and interact with one another. We quickly build a bond that sets the foundation for trust and ultimately, lasting business relationships. If you aren’t a believer yet, ask yourself why you make an effort to attach smiley faces to sensitive emails? Why do you put extra question marks or exclamation points at the end of exasperated emails? We inherently know that we need to overemphasize via email because we have that urge to communicate what is only possible through face-to-face communication. Check out our free trial and start experiencing the benefits of face to face communication today. Many types of communications that we know . There are verbal communication, communication through telephone calls, letters, by emails, whatsapp and so on. But I think that verbal communication , talk face to face is the best and a lot of advantages over other forms of communication. Lots of things to explain the advantages of verbal communication than communication through telephone calls, emails and so on. Benefits that are easy to understand first and more obvious. Verbal communication is very important in everyday life. We can express to someone what is in our hearts and minds through words. Others will easily understand what the message to be communicated simply and clearly. We can speak with confidence when we got to see face to face of the person listening. Certainly when it is in good condition and each can understand. Sometimes communicate through telephone calls, email and so can not reflect the seriousness of the person who spoke not being able to see through these people’s feelings. Advantages of oral speech can also respond quickly when given query immediately and this will expedite the processing. No need to wait for a response from one to two days, but with immediate effect. When speaking verbally, we will be able to detect a person’s honesty with eyes of faith. From the eyes down to the heart. For example, when a person expresses his feelings or inconvenience we will also feel it. But if communication through writting or letters, we can only read without any deep feelings. But because this indirectly will create goodwill between them sooner . In modern society, with the rapid development of technology, people have more choices ways to communicate each other such as face to face, letters, emails, or telephones. However, I believe that face to face communication is much better than others, and in this essay, I will analyze some advantages of this kind of communication to support my opinion. First of all, when people communicate each other in person, they can get responses immediately without misunderstanding. During conversation, people can not only hear responses from others, also see how they are feeling; people can guest what will take place next, how conversation is on, which is very important to have a successful talk. For example, in criminal inspection, face to face communication can know whether or not suspects are telling the truth through the way suspects answer questions, their facial, behaviors and eyes sight. In addition, using face to face communication helps people express their feelings, ideas much better. Instead of using word only when people choose letters, emails or phone for communication, people can use eye contact, verbal language in order to show their opinions. Scientists show that more than seventy percent people use body or verbal language in communicating; thus, it very important for people use actions to express views. Last but not least, conversations seem to be longer when people communicate in person. And of course, the more people talk together, the stronger and better relation they have. Take my friend for example. He is an insurance consultant, and he is very busy with his work; however, whenever his customers need advices, he always meets them in person never through phones, emails no matter how important customers they are. He believe that will make relationship with customers stronger and it is a key factor for success in his field. To sum up, I believe that no matter how developed means of communication they are, face to face is still the most important and effective way for communication. As much as, some telecommunications such as e-mail and telephone calls save our time without spending a lot of time in long distances or in traffic jams for talking with someone else, sometimes in some special issues it is necessary to talk face-to- face. First of all, while individuals talk they have some gestures in their face and hands during speaking. These gestures have meaning which are related to the topic of conversation, and they can be really helpful for listener to understand the meaning of speaker in the best way. Second of all, there are some topics which are really important and have a large number of derails. Discussion about these kind of topics on the phone or writing all details on a piece of paper or via e-mail is too time consuming and also it can cause misinterpret. All in all, there is no doubt that communication with letters, e-mail and telephone have benefits for us such as saving our time; however, in some situations face-to-face communication help listener to get the gist of issue with the help of gestures and it can prevent misinterpret which might happen on the phone or via e-mail. Essay/Article – 1 Many people hold the view that face-to-face communication is better than other types of communication, such as letter, email, or telephone calls. As far as I am concerned, I do not agree with that view. There are many reasons that support my point of view, and I would explore a few of the most important ones here. The main reason is that people live and work with a fast pace nowadays. They are busy with everything. However, they also need to communicate with their friends or relatives. The result is that they have no time to set an appointment. This situation is very common. The best solution is to communicate by letters, e-mails or telephone calls. We could write letters or emails in our leisure time and send them out immediately or call somebody and talk for a few minutes. These things would not take up a long time and can be scheduled quite easily. Another reason is that it is too time and money-consuming for two friends that live away from each other to schedule a face-to-face meeting. In this situation, using letters, e-mail or telephone calls will be a better way. People by this means could communicate with each other conveniently no matter how far they apart. Take one of my friends for example, he communicates with one of his friend in Germany by using emails. Furthermore, I believe that sometimes people will find it difficult to communicate face-to-face. They need to talk about something that is hard for them to confronting each other. At this time, letter, email or telephone calls are better ways of interaction. Given the factors I outlined above, we may reach the conclusion that communication by letters, emails, or telephone calls is better than face-to-face communication. Essay/Article – 2 Since the beginning of time the most important method of communication has been the face-to-face communication. In fact for a long time, face-to-face communication was the only method used. As time progressed new methods came along with the use of letters, telephone calls, and emails. Even with these improvements in communication, nothing has been able to replace the face-to-face method. One reason that face-to-face communication is better than newer methods is that it allows one person to see the facial expressions of another. When a person is talking about good news they usually smile and their eyes light up. Or when a person is having a serious conversation, their eyebrows are usually lower and they keep a straight face on while talking. Without these facial expressions it can be tricky to figure out a person’s meaning behind what he says. Another reason why face-to-face communication is important is that you can tell whether the person is telling the truth or not. When people communicate over the phone or through an email it is impossible to tell when a person is lying. But when it comes to personal communication it is not as easy to get away with a lie. Many people in business prefer this face-to-face method because it helps them to figure out if the person speaking is honest enough to go into business with. When it comes to face-to-face communication there is one more reasons why it is better than other method of communication. When a person is expressing feelings of love or sympathy, no other method of communication will express them perfectly. When a person is showing his/her love for someone, he/she must do it face-to-face so that the other party can see how much he/she mean what he/she says. Also when it comes to expressing sympathy for someone, using any other types of communication is just not enough. By calling someone or emailing him/her to express sympathy, it just shows that you do not have the time to care enough to go over and say it in person. For the reasons listed above, face-to-face communication will always be better than other types of communication. But while face-to-face communication is better, newer methods cannot be ignored. These methods have helped to carry communication over through ling distances around the world; thereby expanding the world we live in and bring everyone closer together. Through the use of letters, telephone calls and emails, a person living in New York now communicate with his/her loved one as far away as South Africa. Essay/Article – 3 With the rapid growth of high technology, computer, telephone and other communication tools have become more and more important in our daily life, so what people have gradually ignored communication? If I were asked whether face-to-face communication is better than other forms of commutations, such as emails, phone calls or letters, I would choose email and phone calls. Here I am going to enumerate some reasons to support my choice. The main reason is that communication by telephone or by email is more convenient. There is no need to make appointment with fiends before meetings; all you need is just remember their phone numbers or email addresses. Whenever you are and whenever it will be, communication is easy as face-to-face talking. Moreover, it is more efficient for people to communicate. Another important reason is that the way people connect by email can make more friends. I have many friends on the Internet and we communicate with each other regularly, so I have gained more information and knowledge in many other fields. Last but not least, indirect communication such as emails and phone calls can avoid direct confrontation and embracement. Sometimes we may not feel comfortable to borrow something or ask for a favor from our friends, because we are afraid of being rejected. At this time, an email or a phone call can be more convenient and can avoid embarrassment. If all these factors are contemplated, the advantages of communication through email or telephone carry more weight than those face-to-face communications. We all know how technology enables communication – email, voicemail, text message, instant message, Twitter . . . the list goes on. There are more than enough ways to communicate, and too often they add up to message overload for employees. That’s why when something is important, nothing compares to communicating face to face. When a leader needs to inspire people—or move them to action—the best way to do it is to look people in the eye and tell them exactly what they need to know. Communicating face-to-face sends a message before you say a word. People will not only hear what you are saying, they will perceive the greater meaning of your tone, voice inflection, emotion and body language. Here are six good reasons for leaders to make the time to communicate face to face: Demonstrate importance – Being there in person tells your audience they are important to you and the issue you are discussing is worth your time and theirs. Your focus will get people’s attention and increase the potential for your message to be heard. Interpret thoughts and feelings – When you are face to face, you can see and respond to people’s reactions – like facial expressions and body language – as well as their tone of voice. Leaders have the chance to show they care by asking probing questions and actively listening to understand the audience’s perspective. This is especially critical when you need employees to adopt new behaviors to advance your goals, such as in times of change. Enhance credibility and trust – Leaders need to build employee trust to be effective. Face-to-face situations allow you to share your strategy, explain it clearly, and answer questions honestly. Employees see how actions align with words, which enhances leaders’ credibility and trust. Build relationships – Interacting directly with other leaders, managers and employees expands your network and establishes shared experience that can enhance future communication. It also helps create camaraderie that is the basis of cooperation and success across the organization. Gather feedback – Meeting in person helps employees feel valued and gives them a chance to contribute input to organizational strategies and communication. It gives the leader a chance to confirm people’s understanding of key issues, identify gaps and encourage ongoing feedback and engagement. Address sensitive issues – You demonstrate respect for employees and a commitment to a successful outcome when you deal with a sensitive issue face to face. Whether you are providing specific feedback to increase their success or delivering a tough message, focus on your desired outcomeand prepare by understanding the employee’s mindset and possible reactions. Ultimately your involvement means a lot and taking the time to meet can help turn a challenging conversation into a trust-building interaction.

What Is the Median in Statistics

It’s the midnight showing of the newest hit movie. People are lined up outside the theater waiting to get in. Suppose you’re asked to find the center of the line. How would you do this? There are a couple of different ways to go about solving this problem. In the end you would have to figure out how many people were in the line, and then take half of that number. If the total number is even, then the center of the line would be between two people. If the total number is odd, then the center would be a single person. You may ask, What does finding the center of a line have to do with statistics? This idea of finding the center is exactly what is used when calculating the median of a set of data. What Is the Median? The median is one of the three primary ways to find the average of statistical data. It is harder to calculate than the mode, but not as labor intensive as calculating the mean. It is the center in much the same way as finding the center of a line of people. After listing the data values in ascending order, the median is the data value with the same number of data values above it and below it. Case One: An Odd Number of Values Eleven batteries are tested to see how long they last. Their lifetimes, in hours, are given by 10, 99, 100, 103, 103, 105, 110, 111, 115, 130, 131. What is the median lifetime? Since there is an odd number of data values, this corresponds to a line with an odd number of people. The center will be the middle value. There are eleven data values, so the sixth one is in the center. Therefore median battery life is the sixth value in this list, or 105 hours. Note that the median is one of the data values. Case Two: An Even Number of Values Twenty cats are weighed. Their weights, in pounds, are given by 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 9, 10, 10, 10, 11, 12, 12, 13. What is the median feline weight? Since there is an even number of data values, this corresponds to the line with an even number of people. The center is between the two middle values. In this case the center is between the tenth and eleventh data values. To find the median we calculate the mean of these two values, and obtain (78)/2 7.5. Here the median is not one of the data values. Any Other Cases? The only two possibilities are to have an even or odd number of data values. So the above two examples are the only possible ways to calculate the median. Either the median will be the middle value, or the median will be the mean of the two middle values. Typically data sets are much larger than the ones that we looked at above, but the process of finding the median is the same as these two examples. The Effect of Outliers The mean and mode are highly sensitive to outliers. What this means is that the presence of an outlier will dramatically affect both of these measures of the center. One advantage of the median is that it is not influenced as much by an outlier. To see this, consider the data set 3, 4, 5, 5, 6. The mean is (34556)/5 4.6, and the median is 5. Now keep the same data set, but add the value 100: 3, 4, 5, 5, 6, 100. Clearly 100 is an outlier, as it is much greater than all of the other values. The mean of the new set is now (34556100)/6 20.5. However, the median of the new set is 5. Although the Application of the Median Due to what we have seen above, the median is the preferred measure of average when the data contains outliers. When incomes are reported, a typical approach is to report the median income. This is done because the mean income is skewed by a small number of people with very high incomes (think Bill Gates and Oprah).