CONTOH LAPORAN RESMI PENETAPAN KADAR ZAT ORGANIK

PENETAPAN KADAR ZAT ORGANIK( BILANGAN / ANGKA PERMANGANAT )

No. SAMPEL …………

1.    Landasan Teori

Adannya zat organik dalam air menunjukan bahwa air tersebut telah tercemar oleh kotoran manusian, hewan atau sumber lain. Zat organik merupakan bahan makanan bakteri atau mikroorganisme lainya. Makin tinggi kandungan zat organik didalam air, maka semakin jelas bahwa air tersebut telah tercemar.

Bilangan / angka permanganat adalah jumlah mg KMnO₄ yang diperlikan untuk mengoksidasi zat organik yang terkandung di dalam satu litercontoh air dengan pendidihan selama 10 menit. Penentuan zat organik dengan cara oksidasi dapat dilakukan dalam suasana asam maupun basa.

·         Metode asam untuk air yang mengandung ion Cl < 300 ppm

Prinsip metode asam :

Zat organik didalam sampel dioksidasi oleh KMnO₄ berlebih dalam keadaan asam dan panas. Sisa KMnO₄ direduksi dengan larutan asam oksalat berlebih. Kelebihan asam oksalat dititrasi kembali dengan KMnO_4.

·         Metode basa untuk air yang mengandung ion Cl > 300 ppm

Prinsip metode basa :

Sampel dididihkan terlebih dahulu dengan NAOH selanjutnya dioksidasi oleh KMnO₄  berlebih. Sisa KMnO₄ direduksi oleh asam oksalat berlebih. Kelebihan asam oksalat dititrasi kembali dengan KMnO_4.

Gangguan

1.    Ion sulfida dan nitrit, untuk menghilangkan harus dipanaskan dengan H₂SO₄ encer sampai H₂S dan nitrit hilang.

2.    Garam ferro dapat dihilangkan dengan penambahan beberapa tetes KMnO₄ sebelum dianalisa sampailarutan tepat merah muda.

3.    Bila harus disimpan lebih dari satu hari, lebih baik diasamkan kurang dari 5 ( pH<5 )

2.    Tujuan

Untuk menentukan kadar zat organik ( bilangan / angka permanganat ) dalam sampel air

3.    Prinsip Percobaan

Reaksi Reduksi-Oksidasi :

Zat organik yang terdapat dalam air dioksidasi oleh KMnO₄ yang ditambahkan secara berlebih pada keadaan asam dan panas, sisa KMnO₄  direduksi oleh H₂C₂O₄  berlebih, kelebihan H₂C₂O₄  dititrasi kembali dengan KMnO_4.

4.    Reaksi Yang Terjadi

·         Oksidasi KMnO₄  dalam kondisi asam:

2 KMnO₄ + 3 H₂SO₄          2 MnSO₄ + K₂SO₄ + 3 H₂O + 5 On

·         Oksidasi KMnO₄  dalam kondisi basa :

2 KMnO₄ + H₂O           2 MnO₂ + 2 KOH + On

H₂C₂O₄  + On           2 CO₂ +  H₂O

5.    Reagen Yang Digunakan

Larutan H₂SO₄  6 N

Larutan standar KMnO₄  0,0207 N

Larutan standar  primer H₂C₂O₄  0,042 N

 

6.    Cara Kerja Penetapan Kadar

-       Masukkan 10,0 ml sampel kedalam erlenmeyer bebas zat organik.

-       Tambahkan 5 ml larutan H₂SO₄  6 N.

-       Tambahkan 20,0 ml larutan KMnO₄  hingga terbentuk warna merah yang permanen panaskan larutan sampai suhu 70⁰C.

-       Tambahkan lagi secara tepat larutan standar KMnO₄ secara berlebih sampai larutan berwarna merah dan catat volume KMnO₄ .

-       Tambahkan lagi secara tepat larutan standar KMnO₄  secara berlebih sampai warna merah luntur menjadi tidak berwarna dan catat volume H₂C₂O₄ .

-       Panaskan lagi larutan sampai suhu 70⁰C, titrasi kelebihan H₂C₂O₄   dengan larutan standar KMnO₄ sampai terbentuk warna merah muda yang permanen.

7.    Data Percobaan :

a.  Volume sampel

C  10,0  ml

C  10,0  ml

C  10,0  ml

b. Titrasi sampel

C  0,00 - ……………. = ………………..  ml

C  0,00 - ……………. = ………………..  ml

C  0,00 - ……………. = ………………..  ml

Rata-rata digunakan larutan KmnO₄ Sebanyak ………………………………… ml

8.    Perhitungan

N₁ x V₁= V₂ x  N₂ ………………………………………………………………………………………………………

………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………

9.    Kesimpulan

Kadar ………………………. No. Sampel …………. = …………… % 

history punk

History

A punk wearing a leather motorcycle jacket with studs and spikes.

Punk rock was an intentional rebuttal of the perceived excess and pretension found in mainstream music (or even mainstream culture as a whole), and early punk artists' fashion was defiantly anti-materialistic. Generally unkempt, often short hairstyles replaced the long-hair hippie look and the usually elaborate 1970s rock/disco styles. In the United States, dirty, simple clothes - ranging from the T-shirt/jeans/leather jacket Ramones look to the low-class, second-hand "dress" clothes of acts like Television or Patti Smith - were preferred over the expensive or colorful clothing popular in the disco scene.
In the United Kingdom, a great deal of punk fashion from the 1970s was based on the designs of Vivienne Westwood and Malcolm McLaren and the Bromley Contingent. Mainstream punk style was influenced by clothes sold in Malcolm McLaren's shop.^[1] McLaren has credited this style to his first impressions of Richard Hell, while McLaren was in New York City working with New York Dolls. Deliberately offensive T-shirts were popular in the early punk scene, such as the DESTROY T-shirt sold at SEX, which featured an inverted crucifix and a Nazi Swastika. These T-shirts, like other punk clothing items, were often torn on purpose. Other items in early British punk fashion included: leather jackets; customised blazers; and dress shirts randomly covered in slogans (such as "Only Anarchists are pretty"), blood, patches and controversial images.

Punk women in Morecambe in 2003.

Other accoutrements worn by some punks included: BDSM fashions; fishnet stockings (sometimes ripped); spike bands and other studded or spiked jewelry; safety pins (in clothes and as body piercings); silver bracelets and heavy eyeliner worn by both men and women. Many female punks rebelled against the stereotypical image of a woman by combining clothes that were delicate or pretty with clothes that were considered masculine, such as combining a Ballet tutu with big, clunky boots.
Punk clothing sometimes incorporated everyday objects for aesthetic effect. Purposely-ripped clothes were held together by safety pins or wrapped with tape; black bin liners (garbage bags) became dresses, shirts and skirts. Other items added to clothing or as jewellery included razor blades and chains. Leather, rubber and vinyl clothing have been common, possibly due to their connection with transgressive sexual practices, such as bondage and S&M.^{[original research?]}
Preferred footwear included military boots, motorcycle boots, brothel creepers, Puma Clydes (suede), Chuck Taylor All-Stars and later, Dr. Martens boots. Tapered jeans, tight leather pants, trousers with leopard patterns and bondage pants were popular choices. Other early punks (most notably The Adicts) imitated the Droogs from A Clockwork Orange by wearing bowler hats and braces. Hair was cropped and deliberately made to look messy, and was often dyed bright unnatural colors. Although provocative, these hairstyles were not as extreme as later punk hairstyles.

1980s

Early 1980s punk fashion.

In the 1980s, new fashion styles developed as parallel resurgences occurred in the United States and United Kingdom. What many recognize as typical punk fashions today emerged from the 1980s British scene, when punk underwent its Oi!/street punk, and UK82 renaissance. The US scene was exemplified by hardcore bands such as Black Flag, Minor Threat, and Fear. The 1980s American scene spawned a utilitarian anti-fashion that was nonetheless raw, angry, and intimidating. However, elements of the 1970s punk look never fully died away.

UK punks wearing elements of early and 1980s punk fashions, circa 1986.

Some of the following clothing items were common on both sides of the Atlantic Ocean, and some were unique to certain geographic areas. Footwear that was common in the 1980s punk scene included Dr. Martens boots, motorcycle boots and combat boots; sometimes adorned with bandanas, chains or studded leather bands. Jeans (sometimes dirty, torn or splattered with bleach) and tartan kilts or skirts were commonly worn. Leather skirts became a popular item for female punks. Heavy chains were sometimes used as belts. Bullet belts, and studded belts (sometimes more than one worn at a time) also became common.
Some punks bought T-shirts or plaid flannel shirts and wrote political slogans, band names or other punk-related phrases on them with marker pens. While this was not without precedent in the 1970s, the depth and detail of these slogans were not fully developed until the 1980s. Silkscreened T-shirts with band logos or other punk-related logos or slogans were also popular. Studded, painted and otherwise customised leather jackets or denim vests became more popular during this era, as the popularity of the earlier customized blazers waned. Hair was either shaved, spiked or in a crew cut or Mohawk hairstyle. Tall mohawks and spiked hair, either bleached or in bright colors, took on a more extreme character than in the 1970s. Charged hair, in which all of one's hair stands on end but is not styled into distinct spikes, also emerged. A hairstyle similar to The Misfits' devilocks was popular. This involved cutting a mohawk but leaving a longer tuft of hair at the front of the head. It is still popular to this day in the Horror-Punk scene. Body piercings and extensive tattoos became very popular during this era, as did spike bands and studded chokers. Some hardcore punk women reacted to the earlier 1970s movement's coquettish vibe by adopting an asexual style.

Gothic rock, deathrock and horror punk

Gothic rock, deathrock and horror punk

Death-rockers in 2007.

Deathrock and horror punk fashion is similar to goth fashion. Black is the predominant shade. Deathrock and horror punk incorporates a sexier image, incorporating fishnets, corsets and elaborate make-up for men and women. The use of occult and horror imagery is prevalent on T-shirts, buttons, patches and jewellery. Other common adornments include band names painted on jackets or bleached into clothes, as well as buttons or patches indicating cities. The initials D and R (for Death Rock) is sometimes part of a crossbone logo, accompanied by other initials, such as C and A for California, N and Y for New York, or G and R for Germany. Hair may be in a deathhawk style (a wider teased-out variant of the mohawk hairstyle), an angled bangs style, or a devilock style.

punk fashion

Punk fashion is the clothing, hairstyles, cosmetics, jewelry, and body modifications of the punk subculture. Punk fashion varies widely, ranging from Vivienne Westwood designs to styles modeled on bands like The Exploited. The distinct social dress of other subcultures and art movements, including glam rock, skinheads, rude boys, greasers, and mods have influenced punk fashion. Punk fashion has likewise influenced the styles of these groups, as well as those of popular culture. Many punks use clothing as a way of making a statement.
Punk fashion has been extremely commercialized at various times, and many well-established fashion designers — such as Vivienne Westwood and Jean Paul Gaultier — have used punk elements in their production. Punk clothing, which was initially handmade, became mass produced and sold in record stores and some smaller specialty clothing stores by the 1980s. Many fashion magazines and other glamor-oriented media have featured classic punk hairstyles and punk-influenced clothing.

ilusi mata

image