Redoks 1 dan redoks 2

Tugas ini saya selesaikan dalam rangka laporan yang harus disetor selesai praktikum kimia

Reaksi Redoks 1

Standar Kompetensi :

Menerapkan konsep reaksi oksidasi – reduksi dan elektrokimia dalam tehnologi dan kehidupan sehari-hari
Kompetensi Dasar :

Menerapkan konsep reaksi oksidasi-reduksi dalam sistem elektrokimia yang melibatkan energi listrik dan kegunaanya dalam mencegah korosi dan dalam industri 

I. TUJUAN
Mempelajari peristiwa reaksi redoks 

II.TEORI
Reaksi redoks merupakan reaksi reduksi dan reaksi oksidasi . Reaksi reduksi adalah peristiwa suatu zat menerima elektron. Sedangkan reaksi oksidasi adalah peristiwa suatui zat melepas elektron. Reaksi redoks dapat diamati dengan terjadinya perubahan warna, terjadinya endapan,timbulnya gas, atau terjadinya energi. 

III. ALAT DAN BAHAN
A. Alat
1. Tabung reaksi
2. Rak tabung reaksi
3. Gelas kimia 100 ml
4. Silinder ukur 100 ml
5. Silinder ukur 10 ml
6. Pipet tetes
7. Termometer
B. Bahan
1. Larutan Na2S2O3 0,2 M
2. Larutan HCl 1 M
3. Larutan KMnO4 0,1 M
4. Larutan H2C2O4 0,1 M
5. Larutan H2SO4 2 M
6. Larutan I2 0,1 M
7. Larutan KI 0,5 M
8. Larutan H2O2 10 % 

IV. CARA KERJA
A. Reaksi antara KMnO4, H2SO4 dan H2C2O4
1. Mengisi sebuah tabung reaksi dengan 2 mL larutan KMnO4 0,1 M
2. Menambahkan 10 tetes H2SO4 2 M ke dalam larutan tersebut
3. Memanaskannya sampai ± 60 o C
4. Setelah suhu mencapai 60 oC , teteskan larutan H2C2O4 0,1 M tetes demi tetes sampai terjadi perubahan warna.
B. Reaksi antara I2 dengan Na2S2O3
1. Mengisi sebuah tabung reaksi dengan 2 mL larutan I2 0,1 M
2. Menambahkan tetes demi tetes larutan Na2S2O3 sampai terjadi perubahan warna
C. Reaksi antara KI dengan H2O2
1. Mengisi sebuah tabung reaksi dengan 2 mL larutan KI 0,5 M
2. Menambahkan 10 tetes larutan H2O2 10 %
3. Mengamati perubahan yang terjadi
D. Reaksi antara Na2S2O3 dengan HCl
1. Mengisi sebuah gelas kimia dengan 25 mL larutan Na2S2O3 0,2 M
2. Memasukkan 5 mL larutan HCl 1 M ke dalam larutan tersebut
3. Mengamati perubahan yang terjadi 

V. HASIL PENGAMATAN
Percobaan Reaksi Pengamatan
A.  KMn04 + H2SO4+H2C2O4 

Warnanya setelah dipanaskan hingga suhunya 60 dan ditetesi H2C2O4 7-8 tetes maka warnanya menjadi berubah dari ungu menjadi  coklat dan ada sedikit endapan.

B. I2 + Na2S2O3 

Warnanya berubah setelah ditetesi Na2S2O3 3-4 tetes menjadi bening dari awalnya berwarna Oranye.

C. KI+ H2O2 

Setelah diteteskan 10 tetes larutan H2O2 10% warnanya berubah dari putih menjadi bening.
D. Na2S2O3 + HCl

Setelah dimasukkan 5ml larutan HCL 1M ke dalam 25 ml larutan Na2S2O3 0,2 M warnanya berubah dari bening menjadi putih keruh, dan ada sedikit endapan.

VI. PERTANYAAN
Tuliskan persamaan reaksi redoks yang terjadi 

A. KMnO₄ + H₂SO₄ + H₂C₂O₄ è K₂SO₄ + MnSO₄ + CO₂ +  H₂O

B. I₂ + N₂S₂O₃  è NaI  + Na₂S₄O₆

C. KI + H₂O₂ è KIO₃ + H₂O

D. Na₂S₂O₃ + HCl è NaCl + SO₂ + H₂O + Cl₂

VII. KESIMPULAN 

Larutan yang mengalami perubahan warna seperti larutan di atas merupakan contoh suatureaksi redoks dalam suasana asam, basa, dan netral .Perubahan warna menunjukkan bahwalarutan bereaksi dan mengalami reaksi redoks.

Reaksi redoks 2
Standar Kompetensi : Menerapkan konsep reaksi oksidasi – reduksi dan elektrokimia dalam tehnologi dan kehidupan sehari-hari
Kompetensi Dasar : Menerapkan konsep reaksi oksidasi-reduksi dalam sistem elektrokimia yang melibatkan energi listrik dan kegunaanya dalam mencegah korosi dan dalam industri

I. TUJUAN

Menyelidiki reaksi logam dengan air.
Menyelidiki logam-logam yang dapat mendesak ion H+ dari larutan asam

II. TEORI
Reaksi redoks ( reduksi dan oksidasi ) terjadi secara bersamaan. Zat-zat reaktan yang menerima elektron berarti mengalami reduksi, sedangkan reaktan yang melepaskan elektron berarti mengalami oksidasi. Zat yang mengalami oksidasi mengalami kenaikan biloks ( bilangan oksidasi ), dan zat yang mengalami reduksi mengalami penurunan biloks. Air merupakan elektrolit lemah yang dapat terionisasi menghasilkan ion H+ dan ion OH -. Bila logam bereaksi dengan air, sebagian ada yang larut ( mampu mendesak ion H+ dari air ), dan sebagian lagi tidak dapat larut. Demikian pula halnya dengan reaksi logam dengan larutan lain, misalnya larutan HCl, HNO3 dan lain-lain.

III. ALAT DAN BAHAN
A. Alat
Tabung reaksi dan raknya
Kertas ampelas
Gunting kaleng
B. Bahan
Logam Cu,Fe,Pb,dan Zn, yang masing-masing berbentuk lempengan
Logam Mg yang berbentuk pita
Larutan HCl
Air

IV. CARA KERJA
1. Gunting logam- logam bahan praktikum dengan ukuran 3 cm x 0,5 cm masing-masing sebanyak 2 potong. Ampelas permukaannya hingga bersih.
2. Sediakan 5 tabung reaksi dan masukkan 1 potongan tiap logam tadi kedalam tiap tabung berturut-turut : Cu, Fe, Mg, Pb, dan Zn. Tambahkan air ke dalam masing-masing tabung reaksi hingga setinggi 2 cm diatas logam . Amati dan catat perubahan yang terjadi di dalam tabung.
3. Tuangkan ke dalam 5 tabung reaksi yang lain masing-masing sebanyak 2 mL larutan HCl 4 M. Kemudian tambahkan ke dalam masing-masing tabung tersebut 1 potongan logam tadi secara berturut-turut : Cu,Fe, Mg, Pb, dan Zn. Amati dan catat perubahan yang terjadi di dalam tabung.


V. HASIL PENGAMATAN
No Logam Pengamatan reaksi logam dengan
air

1 Tembaga ( Cu )

Setelah dimasukkan logam Cu kedalam tabung reaksi yang berisi air dan didiamkan beberapa menit tidak ada perubahan yang terjadi.

2 Zink ( Zn )

Setelah dimasukkan logam Zn kedalam tabung reaksi yang berisi air dan didiamkan beberapa menit tidak ada perubahan yang terjadi.

V. HASIL PENGAMATAN

No Logam Pengamatan reaksi logam dengan
air Larutan HCl 4 M

1 Tembaga ( Cu )

Setelah dimasukkan logam Cu kedalam tabung reaksi yang berisi Larutan HCl 4 M

dan didiamkan beberapa menit warna tembaga memudar.

2 Zink ( Zn )

Setelah dimasukkan logam Zn kedalam tabung reaksi yang berisi Larutan HCl 4 M dan didiamkan beberapa menit  ada gelembung di permukaan

VI. PETANYAAN
1. Menurut anda, logam manakah yang bereaksi dengan air dan manakah yang bereaksi dengan asam ? Tuliskan persamaan reaksi redoksnya.
Dalam percobaan kali ini tidak ada logam yang bereaksi dengan air. Seadangkan seballiknya semua logam dapat bereaksi degan asam.

Persamaan reaksi redoksnya :

-Cu + 2HCl → CuCl₂ + H₂

- Zn + 2HCl → ZnCl₂ + H₂

2. Jelaskan mengapa ada logam yang dapat bereaksi dengan air atau dengan asam, dan ada logam yang tidak dapat bereaksi.
Karena pada reaksi air dengan logam, air merupakan elektrolit lemah yang sulit untuk bereaksi. Ada sebagian logam yang dapat larut(bereaksi) di dalam air dan sebagian lagi tidak dapat. Dalam percobaan kali ini, air tidak dapat melarutkan logam-logam. Sedangkan pada logam dengan asam, masing-masing dapat dengan mudah melepaskan atau menangkap electron. Hal ini yang menyebabkan logam dengan asam dapat menghasilkan suatu reaksi redoks.

VII. KESIMPULAN
Dari percobaan yang telah dilakukan, diketahui bahwa logam Cu, Fe, Mg, Pb dan Zn tidak dapat bereaksi dengan air. Namun logam tersebut dapat bereaksi dengan HCl. Logam Cu direaksikan dengan HCl menghasilkan pemudaran warna pada logam Cu. Serbuk Fe direaksikan dengan HCl menghasilkan gelembung dan endapan. Logam Mg direaksikan dengan HCl menghasilkan gelembung udara dan lama kelamaan logam Mg melarut. Logam Pb direaksikan dengan HCl menghasilkan pemudaran warna pada logam Pb. Logam Zn direaksikan dengan HCl menghasilkan gelembung udara pada permukaan logam.

Design Tips For Ebay Templates.

Templates are the design elements that you might have noticed some sellers using on their auctions, like the borders around the edge, & the different fonts. Lots of sellers who are new to eBay don't bother using them, & you might not have either aa usually, a descriptive listing & a nice picture will do the job fine.

In the event you require to finish your auctions off & make an excellent impression on your buyers though, it is useful to have a nice template. Here are a few tips on what to do & what not to do.

Pick something appropriate. The key part of your template is what you pick in eBay's listing designer (in step three of the Sell Your Item process), or the equivalent in whatever listing program you are now using. You might prefer to make use of third-party program for this, as eBay's designs can be somewhat unimpressive.

Anyway, the different template designs will usually be themed, with names like 'Computers', 'Toys' or 'Crafts'. Make sure what you pick is appropriate for what you are selling a those flowers might be , but what exactly have they got to do with DVDs?

Put the photograph at the top. The photograph of your item is far more important than the text. Put your best photograph at the top of the description, followed by the text, & then finally any additional pics you have. The full-size photograph of the item is the first thing your buyers require to see when they click your auction a why leave it for last?


Add your logo. A well-designed logo gives a professional air to your auctions, if the colour technique & look fits in with the remainder of the template, & it also serves to generate more recognition when people have seen your auctions before. Pay a logo designer a few dollars to do you a logo in the event you don't have already.

Don't be afraid of sizable fonts. Fonts are supposed to be different sizes sometimes. When you have something important to say, don't be afraid to put it in a bigger font, headline-style� as long as you don't get carried away, of work.

Learn a tiny HTML. It might sound scary, but there's lots of books out there about learning HTML, as well as a tiny goes a long way. One time you know what you are doing, you'll find all sorts of ways to make your auction look better � you'll be able to put complicated information in a table,

Preview your listing. Keep in mind to click that 'Preview listing' button to see what everything's going to look like when it goes live. Nice luck!

 of the best things you can put in to your auction template to make it more appealing to buyers is something called a 'SquareTrade seal'. This seal is a promise that you will handle any disputes using SquareTrade, an independent dispute resolution service. We'll take a closer look at what it is & how to get in the next electronic mail.

The Warning signs of Online Fraud and How to avoid it

The number may appear grim for Web-based commerce. In 2004 in the Unites States alone, computer users logged in over 207,000 Net fraud reports to the U.S. Net Crime Complaint Middle. In the event you look hard at this number, you may be astounded, and a nice bit terrified, by the implication. You may ask, "Is it safe to buy and sell at an online site?"

Put basically, the answer is: yes. The Net is an amazingly powerful tool for business, so you cannot pass it over because of a few crooks and conmen-even in the event that they do appear like they are behind every pop-up window and banner commercial. The truth is that you can generate opportunity and earn more funds online than you could lose in fraud.

Better yet, you could lose absolutely nothing in the event you know the warning signs of fraud and the tricks to keep away from danger in the coursework of your Web-based business dealings.

Whether you are looking to buy or sell goods online, the first-and the best-way to fight fraud is prevention. There's definite warning signs to watch for, which ought to set off a chorus of alarms and flashing red lights in your head. Don't do business with this person! For buyers, these potential warning signs can be when a seller:

asks you to pay through non-traceable avenues, such as Western Union or MoneyGram, or a third party, or by an abroad address. You ought to ask yourself-and the seller-why they or they won't accept payment options that are traceable and convenient for you.

posts an picture on his auction or classified commercial that is obviously from an outside source. Sometimes these images may not even match the type of item, not to mention the brand, that the commercial features.

sells a usually pricey item at cut-rate prices, which is a nice indicator that it could be counterfeit.

a refuses to provide tracking numbers when you buy an item. Tracking numbers are another way to trace a valid transaction.

a offers only excuses, in lieu of help, when your bought item doesn't arrive at your doorstep.


If you are a seller, you ought to be cautious of signs of a suspicious buyer, such as when a buyer:

asks to pay only a quantity of the fee, offering to the pay the rest sometime in the future. This is the elderly excuse from Popeye's mate Wimpy, who always could be heard saying, "I'll gladly pay you Tuesday for a hamburger today." Wimpy never paid Tuesday.

sends you a cashier's check for more funds than the agreed cost "by mistake." In this scam, the buyer then asks you to repay him the difference by personal check, wire transfer, or funds order-before you find out that the cashier's check didn't clear. Think it or not, this system works because cashier's checks can be cashed before they bounce


sends you a cashier's check for the correct amount of money but then demands a refund, requesting that you repay together with your own money. See the process above for how this trick works.

These warning signs, of coursework, are only for a handful of the frauds and scams out there. Conmen are nice at what they do, trying to separate you from your money. That is why it is best to always follow these golden rules of online commerce whenever purchasing or selling on an Net auction or classified site.

Keep your common sense. No matter how nice a deal seems, or how much clients say they need to pay, always keep in mind the elderly adage: "If it sounds nice to be true

Do your business locally. Try to buy and sell from your neighbors as much as feasible. It is safer, more convenient, and better for your local economy. What is more, it saves you the trouble of dealing with foreign vendors and buyers. Though they may be legit, dealing with them can be complicated because of different legal systems and customs, which can make any conflict difficult.

Seal the deal with plastic. Paying for items with credit cards, and allowing your customers to charge for purchases, is a great all-around business decision. Under U.S. law, all plastic purchases are shielded from fraud and allowed to be disputed in case of issues.

Meet at the middle man. Intermediary services are virtual middle men that protect both buyers and sellers from cyber shysters. Services like Escrow act as a holding pen for both payment and sale items until both the buyer and seller are content. Only then will Escrow finish a transaction.

Purchase with PayPal. As Escrow and credit cards do, PayPal guards against fraud for both buyers and sellers. It is a secure and reliable way to transfer money over the Net. No wonder PayPal is the most popular online money transfer service.

As you can see, the odds are actually in your favor when it comes to doing business on online classified or auction sites. The resource of the net is far valuable than to be taken away by a few crooks and conmen. It basically comes down to being smart, sensible, and observant whenever purchasing or selling on the Web. Then again, that is what all nice business is about, whether you are doing it in a mall or on the knowledge superhighway.

Graphic Designing By Everyone?

It appears to be the norm these days that somebody can be thought about a graphic designer to some extent or another. With so lots of programs being built right in to digital camera application, greeting card programs & the standards that come with computer packages these days, it makes it simple for people to get creative & experiment with their design skills. Lots of are at home designing & saving money by generating their own wedding invitations, holiday newsletters, calendars, adverts & far more with borders, clip art, funky fonts & all kinds of themes & color schemes that can be achieved with a click or of the mouse.

Pics may even be basically incorporated in to designs of any media type, print or web, with of the lots of application programs on the market today. But when it comes to pics & pics, a favourite amongst most graphic designers is definitely Photoshop. This program is manufactured by Adobe & has tons of wonderful features & tools that can make any picture in to a work of art with tiny work. It also lets you touch up images that might have been damaged or become worn over time, in addition to having the capability to add text & all kinds of icy effects to artistic projects. Adobe Photoshop does tend to be on the more expensive side, but if bought in a bundled package, you'll not only save money, but you'll also get a few other great design programs that Adobe also develops & sells right along with it � then you can get crazy going to town along with your artistic abilities!

Results will vary of coursework, depending on an individual's degree of experience, schooling in design & length of time working in this area, but even a basic knowledge of a graphic design program can lead to some imaginative results either on a personal or professional level.

Article Marketing: How Best To Submit Your Articles?

Having said that, submitting editorial alone can be a time consuming affair. After all, there's plenty of editorial directories and ezine annoucement lists out there. Each editorial listing has different format requirements and some only cater to definite niches. From my experience, you are better off using an editorial submission application or editorial listing submission service than by hand submitting the articles yourself.

You already know the benefits of editorial promotion as an effective means of generating traffic to your site and getting back links. For continued branding and increasing traffic, it is a nice suggestion to submit articles on a regular basis to editorial directories.

Using an editorial submission application like editorial submitter pro, still requires some work on your part. That is why it is the next least costly option. Still, some automation is better than none. But in case you can afford it, outsourcing editorial submission by using a service is a great option to think about.

The downside is of work, cost expense. You will must dole out some money for the application or for the service of editorial promotion. But look at it this way: time is also money! By saving time in this highly laborious exercise, you can channel your energies to other ways of promotion your site or other more productive work.

Editorial submission service providers are committed to growing their list of editorial listing sites that they submit to. Usually, their list can run in to thousands. Also, they keep their lists up-to-date. You will must manage the list yourself in case you use an editorial submission application.<


http://www.articlemarketer.com

Here are some article submission service providers:

http://www.isnare.com

http://www.submityourarticle.com

The other advantage I also see in not using service is that each article submission service has a different listing list. You most likely get greater exposure if your articles are seen across a gigantic number of directories.

Now for article submission services, which do I recommend? For my own sites, I use a mix of services. I do a forecast on the number of articles that I will probably use in the next few months for promotion a specific site. Also, rules & guidelines differ for each article submission service. I then pick the most suitable choice based on my budget & my needs.

Article listing submission application or outsourcing article submissions are ways to cut down your workload, in case you are a tiny online business owner. I therefore, recommend that you pick an optimal budget-time option that will give you the best mileage for successful article promotion.

Why Not to Start using CGI Proxy sites?

Everyone now these days is concerned with defending their personal knowledge form prying eyes on the net. With the continuing increase cases of stealing personal web identities, plenty of people have been misdirected about what knowledge needs to be hidden on line & the best way to accomplish a more secure Net surroundings. of the most common ideas is that when you start using cgi proxy sites the security level increases.

CGI Proxy sites work by quickly & effectively relaying web page request for users to net sites & back. The CGI Proxy script relays your knowledge without ever revealing exactly who you are. So you are anonymous to the world wide web-site you are visiting. This is done in a near seamless manor with the user only seeing a tiny promotion bar on top of the page. This knowledge is going in both directions with the world wide web-site server speaking to the server hosting the CGI proxy site. The net site server does not know your location (IP address), browser type, language settings, cannot set cookies on your computer & Javascripts may be restricted.

What most users do not recognize is that the cgi proxy server keeps a log of all the activity including web pages visited, user names, passwords, addresses, credit card numbers or anything else a person enters in in the world wide web pages surfed through a cgi proxy. This treasure of knowledge is exactly what people need to hide on the Net but by using a CGI Proxy site you have delivered the knowledge to the CGI Proxy site owwner.


In 99% of cases the world wide web-site being visited ought to be more reliable and secure than a web based cgi proxy service. For example visiting Yahoo mail from a new fast walking CGI Proxy site, Yahoo is less likely to criminally use provided information collected from its sites combined with the knowledge of your location and browser type than a small web-site operator hosting a free CGI Proxy script. While logging in to your yahoo account and not revealing your location (IP) to yahoo may sound positive, the cost you pay is sharing all of your information including passwords with the CGI proxy site owner.

Credit card information, addresses, contacts or any other information entered on a web form while surfing pages through a CGI Proxy site are also available in the server logs. Don't take the unneeded risk along with your personal information, DO NOT USE WEBBASED CGI PROXY SITES FOR ANONYMITY.

CGI Proxy sites do have evolved in to a leading way to bypass network web-site filters that block specific sites. be definite that you know the risk involved in checking your hotmail from work or taking a look at your myspace profile at school. This is a leading source of hijacked profiles for these sites.

Fiber Optics In The Real World

Optic fibers are used widely in the medical field for diagnosing and treating a variety of ailments. Because optic fibers can be made extremely thin and made into flexible strands, they can be used for insertion into blood vessels, lungs and other parts of the body. Optic fibers have been enabling physicians to look and work inside the body through tiny incisions with an instrument called an Endoscope. An Endoscope is a medical instrument made to carry two bundles of optic fibers inside one long tube. One bundle of optic fiber directs light at the tissue being examined, while the other bundle of optic fiber transmits light reflected from the tissue, producing a detailed image. Endoscopes may be designed to look into specific areas of the human body. For example, physicians can use the optic fibers in the Endoscope to examine knees, shoulders and other joints in the body.

Arthroscopy (pronounced ahr-THROS-kuh-pee) is a technique of using another medical instrument called the Arthroscope. This instrument is straight and cylinder-like with a series of lenses and optic fiber bundles that come in sizes of 1/12 to 1/5 inch (2 to 5 millimeters.) The Arthroscope is used to examine a joint in a body, such as knee joints, ankles, elbows, hips and shoulders. This is done by the Arthroscope being inserted into a joint of the body through a small incision. A light is then transmitted by the use of the optic fibers to the tip of the Arthroscope to illuminate the joint. The use of optic fiber through the Arthroscope enables a physician to thoroughly examine a joint for diagnosis or treatment.


Optic fibers used in the Arthroscope can be used to measure temperature and other bodily
attributes as well as being used in performing surgical procedures. The problem most commonly treated by Arthroscopy is torn cartilage in the knee. This is when a small incision is made at the joint for use of the optic fiber in the Arthroscope and then a second incision is made for the use of other surgical instruments to remove the cartilage. The primary advantage of using optic fibers through Arthroscopic surgery is that the operation can be performed through a small incision, resulting in the patient experiencing the least amount of discomfort and a healing time that is much shorter, when compared to the other methods of surgery.

Aside from the uses of the Endoscopes and the Arthroscopes, another widely used function of optic fibers in the medical field is the ability for the optical fibers to be inserted into blood vessels to give a quick and accurate analysis of blood chemistry. Physicians have also found medical use of the optical fibers to direct intense laser light at a wound to stop bleeding or to burn away abnormal tissue. Fiber optic training is necessary in the field of medicine. The use of optic fiber through medical science continues to grow rapidly to everyday to develop more new and advanced medical devices to enable physicians to provide people with better service.