Flame Test Essays

Flame Test Essays Flame Test Paper Flame Test Paper Title: Flame Test Aim: To determine the cation in each of the unknown substance X, Y and Z by observing the flame colour of different metal compounds. Introduction: A distinctive feature of many s-block metals is their ability to produce flame colours. At temperature of a Bunsen flame, a compound will decompose to give gaseous atoms of its constituent elements. When an electron in the gaseous atom absorbs energy from the flame, it will move from an orbital with lower energy to an orbital with higher energy. When such an electron returns from an orbital of higher energy to an orbital of lower energy, a photon with energy equal to the difference in energy of the two orbitals will be emitted. An emission line results. Each element has a unique emission spectrum. A metal can be identified if it has a strong emission line in the visible region of the electromagnetic spectrum. Thus when a compound such as NaCl is vaporized in a flame, ion pairs are converted to gaseous atoms. Na(g) atoms are excited to high energies, and 589nm (yellow) light is emitted as the excited atoms revert to their ground state electronic configurations. : Therefore, the cation in the unknown substances can be identify. Chemicals: Concentrated Hydrochloric acid (about 10 cm3) The following solids (0. 1 g) for flame tests: Barium chloride Calcium chloride Copper (II) chloride Magnesium chloride Potassium chloride Sodium chloride Unknown solids containing a single cation and labelled X, Y and Z Apparatus: Bunsen burner Insulation mat Platinum wire (or Nichrome wire), Watch glass Safety precaution: As concentrated hydrochloric acid is corrosive, skin contact should be avoided. It is preferable to use polythene gloves and wear goggles while handling it. Copper (II) chloride and barium chloride are highly toxic by ingestion. Avoid contact with eyes and skin. When Busen burner is not being used, close the air hole so that you can see the yellow flame. Keep your clothing away from the flame. Procedure: 1. The platinum wire was dipped into concentrated hydrochloric acid and heated in a non-luminous flame until the flame is no longer coloured. 2. A spatula of sample (e. g. barium chloride) was put onto a clean watch glass. 3. The platinum wire is dipped into concentrated hydrochloric acid and then the crushed sample of salt to be tested. . The end of the platinum wire is heated strongly in a non-luminous flame again. 5. The colour of the flame at the wire is observed and recorded. 6. The platinum wire is cleaned thoroughly after testing each solid. The test is repeated with chloride of Ca2+, Cu2+, Mg2+, K+, Na+ and unknown solid X, Y and Z in turn. Results: Compound| Colour of the flame| Cation Presents| Barium chloride| Apple green| | C alcium chloride| Brick red| | Copper(II) chloride| Bluish green| | Magnesium chloride| White| | Potassium chloride| Lilac| | Sodium chloride| Golden yellow| | X| Lilac| K+| Y| Bluish green| Cu2+| Z| Golden yellow| Na+| Discussion: 1. Why do certain metal ions give flame colours in this way? The elements have their outer electrons loosely bound so that they can be easily excited to higher energy levels on heating. As these electrons return to their ground states, radiations are emitted. It happens that for many Group I and II metals, these emitted radiations fall into the visible range of the spectrum, so that they can be seen by eyes, i. e. , visible. 2. What is the function of concentrated hydrochloric acid? It is used to clean the platinum wire. The concentrated hydrochloric acid converts ant contaminated salts to their corresponding chlorides, which are usually more volatile to be vaporized off. It gives better observations as the boiling point of metal chloride is lower and less heat is needed to vaporize it. Besides, the sample of powdered compound whose flame colour is to determined is easier to stuck on the platinum wire. 3. Substance A gives a golden yellow flame in flame test. When an acidified solution of A is treated with silver nitrate solution, a yellow precipitate is formed. The precipitate is insoluble in excess ammonia solution. Name A. Substance A is sodium iodide. Limitation The range of detected elements is small, and the test relies on the subjective experience of the experimenter rather than any objective measurements. The test has difficulty detecting small concentrations of some elements, while too strong a result may be produced for certain others, which tends to drown out weaker signals. Moreover, the test cannot differentiate between all elements. Several metals produce the same flame color while some compounds do not change the color of the flame at all. Source of error The source of error of the experiment include the subjective judgment of the colour by the human eye. Besides, the traces of Impurities from the last substance tested and the position of the wire put in the flame also affect the accuracy of the experiment. Improvement The wire should be moved first through the cooler part of the non-luminous Bunsen flame by approaching from underneath, so that even very volatile substances could colour the flame long enough to be observable. The platinum wire should be cleaned thoroughly before testing for a new compound as impurities or contaminants affect the test results. Conclusion: The cation in the unknown substance X, Y and Z is K+, Cu2+ and Na+ respectively.

The Cheapest and the Most Expensive Christmas Gifts Made By Students

The Cheapest and the Most Expensive Christmas Gifts Made By Students Though the date of Christmas is not moveable and no one keeps it in secret, people still don’t buy gifts preemptively, at least, not all of them. We have gathered ideas for Christmas gifts on different budgets in the hope that these ideas will inspire you. The Cheapest 10 Scores for Wittiness photo:reddit.com If you with your friends established Secret Santa budget that doesn’t fit your budget, here’s a way how to go through this. However, you shouldn’t have much expectations about a Christmas gift you’ll get next year. 2 in 1 photo:reddit.com Looks like this guy is a future politician. He promises not to make worse and this works. This is a very cheap present but you can jeopardize your heritage. A Box Is a Present Itself, Didn’t You Know? photo:reddit.com Boxes, wrapping paper and ribbons cost waaaay too much. It’s a good present because the person can use those boxes and paper for his or her gifts. Besides, you can make it for free if you have been collecting all the boxes and wrapping papers for years. The Alternative for a Box of Chocolate photo:reddit.com An adorable gift for a teacher even though the language should have been more appropriate. To make such a gift, you’ll need $20 for materials and a couple of sleepless nights. Experiments With Clothes What Animal Do You Associate You With? photo:reddit.com T-shirts that you can wear alternative ways are awesome. This is a nice present for your friend that by the was is not expensive. The World Should Know Your Friend Better photo:reddit.com Making fun of your friends is one of the ways to say how much you love them. I think the author of this present thought this way. Now, he should be prepared for the revenge that can come any time. You Are Limited Only By Your ImaginationAnd Drawing Skills photo:reddit.com Even Homer is shocked how nice this guy managed to paint shoes. However, this is not about the Simpsons. This about making not expensive gifts appear more valuable. How Far Can They Go? photo:reddit.com The only T-shirt with the picture of the man wearing it that doesn’t look pathetic. Exes Also Want Presents photo:reddit.com Before unrevealing, that was supposed to be a sweater for a boyfriend. And now it’s a present for an ex. The only condition to make this present is to hate someone enough to waste your time and effort. How Many Pokemons Have You Caught? photo:reddit.com If you worry that a fish won’t survive at your friend’s place, you can place pokemons in a fish bowl instead. Steam Emergency photo:reddit.com This is the case when the package is better and more creative than the present itself. The Most Expensive What Is Your Favorite Movie? photo:reddit.com Don’t look for â€Å"Where’s ham? movie. It’s fake. The author of this present made up fake covers for X-rated movies so that parents of his buddy won’t find out. Making such present is time-consuming and can be expensive for student budget. This Calendar Can Make Your Day photo:reddit.com For such calendar, you might need some stuff. I doubt if each student has a banana costume. Also, this guy had to use PS to fulfill his ideas. The Only Shiba Inu That Can Make You Rich photo:reddit.com Dogecoins can cost a fortune in a couple of years. Think one more time before giving them as a present. Perhaps the Most Expensive Gift Here photo:reddit.com Who could get such an expensive gift? Of course, it’s mom. Such gift would cost you a fortune or $5000 but mom’s hug is priceless, isn’t it? No, the Previous One Wasn’t the Most Expensive photo:reddit.com This is the present of the year, isn’t it? The way to get it is simple, the only thing you need to do is to create a time machine, go back to 2011 and buy it. I hope that some ideas will help you to create your own presents. If you need even more inspiration, check out more Christmas gifts ideas for college students. When selecting or making gifts, remember that more important is your emotions and words that you say, not the gift itdself. Good luck and have a nice holiday!