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Jumat, 27 Maret 2009

Hukum-hukum Dasar Kimia

STOIKIOMETRI adalah cabang ilmu kimia yang mempelajari hubungan kuantitatif dari komposisi zat-zat kimia dan reaksi-reaksinya.

1.

HUKUM KEKEKALAN MASSA = HUKUM LAVOISIER
"Massa zat-zat sebelum dan sesudah reaksi adalah tetap".

Contoh:
hidrogen + oksigen ® hidrogen oksida
(4g) (32g) (36g)

2.

HUKUM PERBANDINGAN TETAP = HUKUM PROUST
"Perbandingan massa unsur-unsur dalam tiap-tiap senyawa adalah tetap"

Contoh:

a. Pada senyawa NH3 : massa N : massa H
= 1 Ar . N : 3 Ar . H
= 1 (14) : 3 (1) = 14 : 3
b. Pada senyawa SO3 : massa S : massa 0
= 1 Ar . S : 3 Ar . O
= 1 (32) : 3 (16) = 32 : 48 = 2 : 3

Keuntungan dari hukum Proust:
bila diketahui massa suatu senyawa atau massa salah satu unsur yang membentuk senyawa tersebut make massa unsur lainnya dapat diketahui.

Contoh:
Berapa kadar C dalam 50 gram CaCO3 ? (Ar: C = 12; 0 = 16; Ca=40)
Massa C = (Ar C / Mr CaCO3) x massa CaCO3
= 12/100 x 50 gram = 6 gram
massa C
Kadar C = massa C / massa CaCO3 x 100%
= 6/50 x 100 % = 12%

3.

HUKUM PERBANDINGAN BERGANDA = HUKUM DALTON
"Bila dua buah unsur dapat membentuk dua atau lebih senyawa untuk massa salah satu unsur yang sama banyaknya maka perbandingan massa unsur kedua akan berbanding sebagai bilangan bulat dan sederhana".

Contoh:

Bila unsur Nitrogen den oksigen disenyawakan dapat terbentuk,
NO dimana massa N : 0 = 14 : 16 = 7 : 8
NO2 dimana massa N : 0 = 14 : 32 = 7 : 16

Untuk massa Nitrogen yang same banyaknya maka perbandingan massa Oksigen pada senyawa NO : NO2 = 8 :16 = 1 : 2

4.

HUKUM-HUKUM GAS
Untuk gas ideal berlaku persamaan : PV = nRT

dimana:
P = tekanan gas (atmosfir)
V = volume gas (liter)
n = mol gas
R = tetapan gas universal = 0.082 lt.atm/mol Kelvin
T = suhu mutlak (Kelvin)

Perubahan-perubahan dari P, V dan T dari keadaan 1 ke keadaan 2 dengan kondisi-kondisi tertentu dicerminkan dengan hukum-hukum berikut:


A.

HUKUM BOYLE
Hukum ini diturunkan dari persamaan keadaan gas ideal dengan
n1 = n2 dan T1 = T2 ; sehingga diperoleh : P1 V1 = P2 V2

Contoh:
Berapa tekanan dari 0 5 mol O2 dengan volume 10 liter jika pada temperatur tersebut 0.5 mol NH3 mempunyai volume 5 liter den tekanan 2 atmosfir ?

Jawab:
P1 V1 = P2 V2
2.5 = P2 . 10 ® P2 = 1 atmosfir

B.

HUKUM GAY-LUSSAC
"Volume gas-gas yang bereaksi den volume gas-gas hasil reaksi bile diukur pada suhu dan tekanan yang sama, akan berbanding sebagai bilangan bulat den sederhana".

Jadi untuk: P1 = P2 dan T1 = T2 berlaku : V1
/ V2 = n1 / n2

Contoh:
Hitunglah massa dari 10 liter gas nitrogen (N2) jika pada kondisi tersebut 1 liter gas hidrogen (H2) massanya 0.1 g.
Diketahui: Ar untuk H = 1 dan N = 14

Jawab:

V1/V2 = n1/n2 ® 10/1 = (x/28) / (0.1/2) ® x = 14 gram

Jadi massa gas nitrogen = 14 gram.

C.

HUKUM BOYLE-GAY LUSSAC
Hukum ini merupakan perluasan hukum terdahulu den diturukan dengan keadaan harga n = n2 sehingga diperoleh persamaan:

P1 . V1 / T1 = P2 . V2 / T2

D. HUKUM AVOGADRO
"Pada suhu dan tekanan yang sama, gas-gas yang volumenya sama mengandung jumlah mol yang sama. Dari pernyataan ini ditentukan bahwa pada keadaan STP (0o C 1 atm) 1 mol setiap gas volumenya 22.4 liter volume ini disebut sebagai volume molar gas.

Contoh:
Berapa volume 8.5 gram amoniak (NH3) pada suhu 27o C dan tekanan 1 atm ?
(Ar: H = 1 ; N = 14)

Jawab:
85 g amoniak = 17 mol = 0.5 mol

Volume amoniak (STP) = 0.5 x 22.4 = 11.2 liter

Berdasarkan persamaan Boyle-Gay Lussac:

P1 . V1 / T1 = P2 . V2 / T2
1 x 112.1 / 273 = 1 x V2 / (273 + 27) ® V2 = 12.31 liter

READ MORE - Hukum-hukum Dasar Kimia

History of Australia


Human habitation of Australia is estimated to have begun between 42,000 and 48,000 years ago. These first Australians may have been ancestors of modern Indigenous Australians; they may have arrived via land bridges and short sea-crossings from what is now South-East Asia. Most of these people were hunter-gatherers, with a complex oral culture and spiritual values based on reverence for the land and a belief in the Dreamtime. The Torres Strait Islanders, ethnically Melanesian, were originally horticulturalists and hunter-gatherers. Their cultural practices have always been distinct from those of the mainland Aborigines.

A replica of Lieutenant Cook's ship HM Bark Endeavour in Cooktown Harbour

The first recorded European sighting of the Australian mainland was made by the Dutch navigator Willem Janszoon, who sighted the coast of Cape York Peninsula in 1606. During the 17th century, the Dutch charted the whole of the western and northern coastlines of what they called New Holland, but they made no attempt at settlement. In 1770, James Cook sailed along and mapped the east coast of Australia, which he named New South Wales and claimed for Great Britain.

Cook's discoveries prepared the way for establishment of a new penal colony. The British Crown Colony of New South Wales began a settlement at Port Jackson by Captain Arthur Phillip on 26 January 1788. This date was later to become Australia's national day, Australia Day. Van Diemen's Land, now known as Tasmania, was settled in 1803 and became a separate colony in 1825. The United Kingdom formally claimed the western part of Australia in 1829. Separate colonies were created from parts of New South Wales: South Australia in 1836, Victoria in 1851, and Queensland in 1859. The Northern Territory was founded in 1911 when it was excised from South Australia. South Australia was founded as a "free province"—that is, it was never a penal colony. Victoria and Western Australia were also founded "free" but later accepted transported convicts. The transportation of convicts to the colony of New South Wales ceased in 1848 after a campaign by the settlers.

Port Arthur, Tasmania was Australia's largest gaol for transported convicts.

The Indigenous Australian population, estimated at 350,000 at the time of European settlement, declined steeply for 150 years following settlement, mainly because of infectious disease. The "Stolen Generation" (removal of Aboriginal children from their families), which historians such as Henry Reynolds have argued could be considered genocide by some definitions, may have contributed to the decline in the indigenous population.

Such interpretations of Aboriginal history are disputed by some conservative commentators, such as former Prime Minister Howard, as being exaggerated or fabricated for political or ideological reasons. Historian Keith Windschuttle has argued that the dominant historical interpretation of the treatment of Aboriginal people on the frontiers of white settlement in Australia amounts to a fabrication. He claims this is the result of work done by a generation of politically inspired academics. That work, he charges, is characterised by poor historical method and by lack of evidence, and they have invented stories, made up figures, suppressed evidence, falsely referenced sources and deceived their readers.

This debate is known within Australia as the History Wars. Following the 1967 referendum, the Federal government gained the power to implement policies and make laws with respect to Aborigines. Traditional ownership of land—native title—was not recognised until 1992, when the High Court case Mabo v Queensland (No 2) overturned the notion of Australia as terra nullius (literally "no one's land", effectively "empty land") at the time of European occupation.

The Last Post is played at an ANZAC Day ceremony in Port Melbourne, Victoria. Similar ceremonies are held in most suburbs and towns.

A gold rush began in Australia in the early 1850s, and the Eureka Stockade rebellion against mining licence fees in 1854 was an early expression of civil disobedience. Between 1855 and 1890, the six colonies individually gained responsible government, managing most of their own affairs while remaining part of the British Empire. The Colonial Office in London retained control of some matters, notably foreign affairs, defence, and international shipping. On 1 January 1901, federation of the colonies was achieved after a decade of planning, consultation, and voting. The Commonwealth of Australia was born as a dominion of the British Empire. The Federal Capital Territory (later renamed the Australian Capital Territory) was formed from a part of New South Wales in 1911 to provide a location for the proposed new federal capital of Canberra. (Melbourne was the temporary seat of government from 1901 to 1927 while Canberra was being constructed.) The Northern Territory was transferred from the control of the South Australian government to the Commonwealth in 1911. Australia willingly participated in World War I. Many Australians regard the defeat of the Australian and New Zealand Army Corps (ANZACs) at Gallipoli as the birth of the nation—its first major military action. The Kokoda Track Campaign is regarded by many as an analogous nation-defining event during World War II.

The United Kingdom's Statute of Westminster 1931 formally ended most of the constitutional links between Australia and the UK. Australia adopted it in 1942, but backdated it to the beginning of World War II to confirm the validity of legislation passed by the Australian Parliament during the war. The shock of the UK's defeat in Asia in 1942 and the threat of Japanese invasion caused Australia to turn to the United States as a new ally and protector. Since 1951, Australia has been a formal military ally of the US, under the ANZUS treaty. After World War II, Australia encouraged immigration from Europe; since the 1970s and the abolition of the White Australia policy, immigration from Asia and elsewhere was also encouraged. As a result, Australia's demography, culture, and self-image have been transformed. The final constitutional ties between Australia and the UK were severed with the passing of the Australia Act 1986, ending any British role in the government of the Australian States, and ending judicial appeals to the UK Privy Council. At the 1999 referendum, 54% of Australian voters rejected a proposal to become a republic with a president appointed by two-thirds vote of both houses of the Australian Parliament. Since the election of the Whitlam Government in 1972, there has been an increasing focus on the expansion of ties with other Pacific Rim nations while maintaining close ties with Australia's traditional allies and trading partners.

READ MORE - History of Australia

Jumat, 06 Maret 2009

Acord Dan Lirik Lagu Kotak

Tetap Ada

Kotak

Intro : Bm G D C#m Bm
G D
Tiada pernah ku menduka walau sekali saja
C#m Bm
Awal kali ku berjumpa dengan dirinya
G
Kali ini ku temukan cinta
D
Dalam hati berbicara
C#m Bm
Mungkinkah dia pun merasa
G
Cinta kan tetap ada
D C#m Bm
Tak mampu kelain cinta, hanya dia

G D
Kan ku ungkapkan rasa terpendam dalam jiwa
C#m Bm
Kan ku berikan semua untuk mu ku setia

Interlude : G D C#m Bm

G D
Kini tersisah hanya bayangan tak sempat ku berkata
C#m Bm
Sesal melanda jiwa
G
Cinta kan tetap ada
D C#m Bm
Tak mampu kelain cinta, hanya dia

Reff :
G D
Kan ku ungkapkan rasa terpendam dalam jiwa
C#m Bm
Kan ku berikan semua untuk mu ku setia
G D
Namun kau pejamkan mata untukku selamanya
C#m Bm
Teteskan air mata, selamat jalan cinta

Interlute : D A Bm C#m Bm
Balik ke Reff 2x

Mencinta Ku Dan Dia

Kotak

ntro : F#m
D A F#m
Tanpa aku sadari
D A F#m
Apa yang telah ku beri
D A F#m
Tanpa aku mengerti
D A E F#m
Hingga kau lumpuhkan hati

D A F#m
Takdirkah semua ini
D A F#m
Akhir sesal dihati
D A F#m
Tak bisa aku pergi
D A E
Meski kau tak ku miliki

D E Bm A D
Ku puja, ku damba
Dm A
Yang ku rasa

Reff
E F#m D A
Ku tahu aku yang kedua
E D A
Mungkin kah ku yang utama
E F#m D A
Ku tahu kau pun mencinta
E D
Ku dan dia

D A F#m
Takdirkah semua ini
D A F#m
Akhir sesal dihati
D A F#m
Tak bisa aku pergi
D A E
Meski kau tak ku miliki

Interlute : F#m D F#m D E A
Balik ke Reff 2x

Rock Never Dies

Kotak

Intro : Em G C D 2x Em
G C D Em
Nada mu telah tercipta sebelum aku yang tercipta
G C D Em
Semasa engkau di dunia memperkaya dalam karya

Interlude : C D C D

Reff
Em G
Rock never dies
C D
Sampai kapanpunkan ada
Em G
Rock never dies
C D
Hingga sampai akhir dunia

Interlute : Em G C D Em

G C D Em
Wahai engkaulah jiwa-jiwa warnailah kehidupan
G C D Em
Ungkapkan semua suka cita lewat alunan irama

Interlute : C D C D
Balik ke Reff

Lagi-Lagi

Kotak

Intro : E G C D 4x
E G C D
Malam ini ku lewati
E G C D
Walau sepi menghantui
E G C D
Tak ada dambaan hati kan tetap ku nikmati

E G C D
* Hati kecilku berbisik
E G C D E G C D
Inginkan kekasih tapi ku masih inginkan sendiri
E G C D
Kau pun terus mendekati akupun tak peduli

Interlute : E G C D 2x

Reff I
E G
Lagi-lagi, kamu lagi-lagi
C D
Basi-basi, rayuanmu basi
E D C D
Memang ku menarik, aku memang sexy

Balik ke *, Reff

Reff II
E G
Lagi-lagi, kamu lagi-lagi
C D
Pergi-pergi, jangan kau kembali
E D C D
Jangan mimpi aku tak pernah simpati

Interlute : E G C D E D C D 2x
E G C D 2x

Balike ke Reff I, Reff II
Code : E G C D 4x

Terluka

Kotak

Intro : F#mDA2xF#m
D A E F#m
Kalau tak bisa memuji janganlah mencaci
D A E F#m
Lebih baik diam dan tutup mulutmu
D A E F#m
Kalau memang tak suka janganlah melihat
D A E F#m
Lebih baik kau pergi tak ada disini


D A E F#m
* Walau tak sempurna aku juga manusia
D A E F#m
Ingin dicintai, ingin dihargai
D A E F#m
Walau hidup pula yang lebih sempurna
D A
Tapi mulutmu selalu memaki
D Bm
Jangan pernah menoleh
F#m
Ataupun ingin berjumpa
D Bm E
Melihat mu aku benci

Reff
F#m D A E
Terluka aku selalu dengan kata-katamu
F#m D A E
Kau buat aku membenci dirimu
F#m D A E
Terluka aku selalu dengan kata-katamu
F#m D A E
Ku benci, ku benci, ku benci dirimu

Balik ke *, Reff
interlute : F#m D C#m C B

F#m D A E B C# D#m
Terluka aku dengan dirimu
G#m E B F#
Terluka aku selalu dengan kata-katamu
G#m E B F#
Kau buat aku membenci dirimu
G#m E B F#
Terluka aku selalu dengan kata-katamu
G#m E B F#
Ku benci, ku benci, ku benci dirimu

Code : F#m E B F# 2x E

READ MORE - Acord Dan Lirik Lagu Kotak