saco-indonesia.com, indikator Asam Basa Telah disebutkan bahwa asam telah mempunyai rasa asam, sedangkan basa telah mempun

saco-indonesia.com,

indikator Asam Basa

Telah disebutkan bahwa asam telah mempunyai rasa asam, sedangkan basa telah mempunyai rasa pahit. Namun begitu, tidak dianjurkan untuk dapat mengenali asam dan basa dengan, cara mencicipinya, sebab banyak diantaranya yang dapat merusak kulit (korosif) atau bahkan bersifat racun. Asam dan basa juga dapat dikenali dengan menggunakan zat indikator, yaitu zat yang telah meniberi warna berbeda dahlia) lingkungan asam dan lingkungan basa (zat yang warnanya dapat berubah saat berinteraksi atau bereaksi dengan senyawa asam maupun senyawa basa).

Dalam laboratorium kimia, indikator asam-basa yang biasa di gunakan adalah indikator buatan dan indikator alami, Berikut ini penjelasan tentang indikator asam-basa buatan dan indikator asam-basa alami.
Derajat keasaman (pH)

Indikator Tingkat Keasaman Suatu zat asam yang di masukkan ke dalam air akan dapat mengakibatkan bertambahnya ion hidrogen (H+) dalam air dan berkurangnya ion hidroksida (OH- ). Sedangkan pada basa, akan dapat terjadi sebaliknya. Zat basa yang dimasukkan ke dalam air akan dapat mengakibatkan bertambahnya ion hidroksida (OH- ) dan berkurangnya ion hidrogen (H+).

Jumlah ion H+ dan OH- di dalam air dapat di gunakan untuk dapat menentukan derajat keasaman atau kebasaan suatu zat. Semakin asam suatu zat, semakin banyak ion H+ dan semakin sedikit jumlah ion OH- di dalam air. Sebaliknya semakin basa suatu zat, semakin sedikit jumlah ion H+ dan semakin banyak ion OH- di dalam air.
Proses netralisasi

Apabila suatu larutan asam dengan larutan basa akan dicampurkan dalam suatu bejana, maka ion H+ (dari asam) akan bereaksi dengan ion OH- (dari 311 basa) membentuk air. Reaksi antara ion H+ dengan OH- tersebut juga dapat di tuliskan sebagai berikut. H+ + OH- air

ini karena selain air, basil reaksi antara asam dan basa adalah suatu zat yang bersifat netral, yaitu zat yang tidak bersifat asam maupun basa. Zat netral yang di maksudkan di sini adalah garam. Mengingat reaksi netralisasi juga dapat menghasilkan garam, maka reaksi ini juga di kenal dengan istilah reaksi penggaraman. Secara sederhana, reaksi netralisasi atau reaksi penggaraman juga dapat di tuliskan sebagai berikut.

Contoh sederhana dari reaksi penggaraman adalah reaksi antara asam klorida (HC1) dengan natrium hidroksida (NaOH), yang akan dapat membentuk natrium klorida NaCl (garam dapur) dan air. Pada dasarnya, reaksi penggaraman (netralisasi) juga sangat berguna bagi kehidupan manusia.

Reaksi netralisasi tidak hanya terbatas pada pembentukkan garam dan air. Dalam kehidupan sehari-hari banyak dijumpai prinsip atau reaksi netralisasi, termasuk dalam bidang kesehatan dan pertanian. Perhatikan contoh berikut ini : gas-gas sisa, baik yang berasal dari kendaraan bermotor atau pabrik, mengandung gas belerang dioksida dan nitrogen oksida.

Gas-gas ini akan dilepas ke udara sehingga menimbulkan polusi. Gas-gas tersebut juga akan larut dalam titik-titik air di awan sehingga membentuk larutan asam sulfat dan asam nitrat. Ketika terjadi hujan, larutan-larutan ini akan bercampur dan turun bersama hujan. Inilah yang dinamakan dengan hujan asam.

Hujan asam sangat merugikan manusia dan lingkungan. Berikut adalah dampak yang ditimbulkan oleh hujan asam:

    Hujan asam dapat menyebabkan matinya tumbuhan dan ikan. Asam yang telah terdapat dalam air hujan juga dapat bereaksi dengan mineral dalam tanah. Tumbuhan akan menjadi kekurangan mineral sehingga mati atau tidak tumbuh dengan baik. Hujan asam juga dapat melarutkan aluminium dari mineral dalam tanah dan bebatuan, kemudian menghanyutkannya ke sungai sehingga dapat meracuni ikan dan mahluk air lainnya.
    Hujan asam yang bereaksi dengan logam juga dapat merusak jembatan, mobil, kapal laut, dan rangka bangunan. Hujan asam juga dapat merusak bangunan (gedung/ rumah) yang terbuat dari batu kapur.


Editor : Dian Sukmawati

saco-indonesia.com, Polisi akhirnya telah berhasil untuk mengungkap pelaku pembunuhan wanita dalam mobil Nissan March putih F 13

saco-indonesia.com, Polisi akhirnya telah berhasil untuk mengungkap pelaku pembunuhan wanita dalam mobil Nissan March putih F 1356 KA. Satu dari dua pelaku, telah diamankan oleh jajaran Polres Jakarta Timur.

Berdasarkan informasi yang telah berhasil dihimpun, salah satu pelaku berhasil ditangkap, Sabtu (1/2) malam. Petugas tengah menggiring pelaku atas nama Daniel ke Pasar Kecapi, Pondok Gede, untuk dapat menggambil barang bukti motor yang digunakannya.

Daniel sendiri bukanlah pelaku utama atas tewasnya Feby Lorita. Ia hanya bertugas untuk membantu pelaku utama Ed, yang saat ini masih dalam proses pengejaran di Medan. Daniel sendiri juga merupakan seorang angkot yang terbujuk rayu Ed.

Kabar ditangkapnya Daniel sendiri, juga telah dibenarkan oleh Kapolres Jakarta Timur, Kombes Mulyadi Kaharni. Namun, ia belum dapat memberikan keterangan detil atas penangkapan yang dilakukan petugasnya. Melalui pesan singkatnya, Mulyadi hanya menulis. “Iya, sudah tahu kan,” tulisnya.

TIDAK HAMIL

Sementara itu, berdasarkan hasil otopsi yang telah dilakukan petugas, Feby sendiri tidak dalam kondisi hamil. Hanya saja, luka akibat benda tajam terlihat di leher korban. “Dari hasil otopsi korban sendiri tidak hamil,” kata Kasat Reskrim AKBP Didik Sugiarto.

Didik sendiri mengaku, jasad yang ditemukan di bagasi mobil disamping TPU Pondok Kelapa, Duren Sawit, benar Feby Lorita. Hal itu telah teruji dari hasil sidik jari korban yang dibandingkan dengan ijazah SMU miliknya. “Hasilnya identik 100 persen, korban adalah benar Feby Lorita,” tuturnya


Editor : Dian Sukmawati

WASHINGTON — A decade after emergency trailers meant to shelter Hurricane Katrina victims instead caused burning eyes, sore throats and other more serious ailments, the Environmental Protection Agency is on the verge of regulating the culprit: formaldehyde, a chemical that can be found in commonplace things like clothes and furniture.

But an unusual assortment of players, including furniture makers, the Chinese government, Republicans from states with a large base of furniture manufacturing and even some Democrats who championed early regulatory efforts, have questioned the E.P.A. proposal. The sustained opposition has held sway, as the agency is now preparing to ease key testing requirements before it releases the landmark federal health standard.

The E.P.A.’s five-year effort to adopt this rule offers another example of how industry opposition can delay and hamper attempts by the federal government to issue regulations, even to control substances known to be harmful to human health.

Continue reading the main story
 

Document: The Formaldehyde Fight

Formaldehyde is a known carcinogen that can also cause respiratory ailments like asthma, but the potential of long-term exposure to cause cancers like myeloid leukemia is less well understood.

The E.P.A.’s decision would be the first time that the federal government has regulated formaldehyde inside most American homes.

“The stakes are high for public health,” said Tom Neltner, senior adviser for regulatory affairs at the National Center for Healthy Housing, who has closely monitored the debate over the rules. “What we can’t have here is an outcome that fails to confront the health threat we all know exists.”

The proposal would not ban formaldehyde — commonly used as an ingredient in wood glue in furniture and flooring — but it would impose rules that prevent dangerous levels of the chemical’s vapors from those products, and would set testing standards to ensure that products sold in the United States comply with those limits. The debate has sharpened in the face of growing concern about the safety of formaldehyde-treated flooring imported from Asia, especially China.

What is certain is that a lot of money is at stake: American companies sell billions of dollars’ worth of wood products each year that contain formaldehyde, and some argue that the proposed regulation would impose unfair costs and restrictions.

Determined to block the agency’s rule as proposed, these industry players have turned to the White House, members of Congress and top E.P.A. officials, pressing them to roll back the testing requirements in particular, calling them redundant and too expensive.

“There are potentially over a million manufacturing jobs that will be impacted if the proposed rule is finalized without changes,” wrote Bill Perdue, the chief lobbyist at the American Home Furnishings Alliance, a leading critic of the testing requirements in the proposed regulation, in one letter to the E.P.A.

Industry opposition helped create an odd alignment of forces working to thwart the rule. The White House moved to strike out key aspects of the proposal. Subsequent appeals for more changes were voiced by players as varied as Senator Barbara Boxer, Democrat of California, and Senator Roger Wicker, Republican of Mississippi, as well as furniture industry lobbyists.

Hurricane Katrina in 2005 helped ignite the public debate over formaldehyde, after the deadly storm destroyed or damaged hundreds of thousands of homes along the Gulf of Mexico, forcing families into temporary trailers provided by the Federal Emergency Management Agency.

The displaced storm victims quickly began reporting respiratory problems, burning eyes and other issues, and tests then confirmed high levels of formaldehyde fumes leaking into the air inside the trailers, which in many cases had been hastily constructed.

Public health advocates petitioned the E.P.A. to issue limits on formaldehyde in building materials and furniture used in homes, given that limits already existed for exposure in workplaces. But three years after the storm, only California had issued such limits.

Industry groups like the American Chemistry Council have repeatedly challenged the science linking formaldehyde to cancer, a position championed by David Vitter, the Republican senator from Louisiana, who is a major recipient of chemical industry campaign contributions, and whom environmental groups have mockingly nicknamed “Senator Formaldehyde.”

Continue reading the main story

Formaldehyde in Laminate Flooring

In laminate flooring, formaldehyde is used as a bonding agent in the fiberboard (or other composite wood) core layer and may also be used in glues that bind layers together. Concerns were raised in March when certain laminate flooring imported from China was reported to contain levels of formaldehyde far exceeding the limit permitted by California.

Typical

laminate

flooring

CLEAR FINISH LAYER

Often made of melamine resin

PATTERN LAYER

Paper printed to resemble wood,

or a thin wood veneer

GLUE

Layers may be bound using

formaldehyde-based glues

CORE LAYER

Fiberboard or other

composite, formed using

formaldehyde-based adhesives

BASE LAYER

Moisture-resistant vapor barrier

What is formaldehyde?

Formaldehyde is a common chemical used in many industrial and household products as an adhesive, bonding agent or preservative. It is classified as a volatile organic compound. The term volatile means that, at room temperature, formaldehyde will vaporize, or become a gas. Products made with formaldehyde tend to release this gas into the air. If breathed in large quantities, it may cause health problems.

WHERE IT IS COMMONLY FOUND

POTENTIAL HEALTH RISKS

Pressed-wood and composite wood products

Wallpaper and paints

Spray foam insulation used in construction

Commercial wood floor finishes

Crease-resistant fabrics

In cigarette smoke, or in the fumes from combustion of other materials, including wood, oil and gasoline.

Exposure to formaldehyde in sufficient amounts may cause eye, throat or skin irritation, allergic reactions, and respiratory problems like coughing, wheezing or asthma.

Long-term exposure to high levels has been associated with cancer in humans and laboratory animals.

Exposure to formaldehyde may affect some people more severely than others.

By 2010, public health advocates and some industry groups secured bipartisan support in Congress for legislation that ordered the E.P.A. to issue federal rules that largely mirrored California’s restrictions. At the time, concerns were rising over the growing number of lower-priced furniture imports from Asia that might include contaminated products, while also hurting sales of American-made products.

Maneuvering began almost immediately after the E.P.A. prepared draft rules to formally enact the new standards.

White House records show at least five meetings in mid-2012 with industry executives — kitchen cabinet makers, chemical manufacturers, furniture trade associations and their lobbyists, like Brock R. Landry, of the Venable law firm. These parties, along with Senator Vitter’s office, appealed to top administration officials, asking them to intervene to roll back the E.P.A. proposal.

The White House Office of Management and Budget, which reviews major federal regulations before they are adopted, apparently agreed. After the White House review, the E.P.A. “redlined” many of the estimates of the monetary benefits that would be gained by reductions in related health ailments, like asthma and fertility issues, documents reviewed by The New York Times show.

As a result, the estimated benefit of the proposed rule dropped to $48 million a year, from as much as $278 million a year. The much-reduced amount deeply weakened the agency’s justification for the sometimes costly new testing that would be required under the new rules, a federal official involved in the effort said.

“It’s a redlining blood bath,” said Lisa Heinzerling, a Georgetown University Law School professor and a former E.P.A. official, using the Washington phrase to describe when language is stricken from a proposed rule. “Almost the entire discussion of these potential benefits was excised.”

Senator Vitter’s staff was pleased.

“That’s a huge difference,” said Luke Bolar, a spokesman for Mr. Vitter, of the reduced estimated financial benefits, saying the change was “clearly highlighting more mismanagement” at the E.P.A.

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The review’s outcome galvanized opponents in the furniture industry. They then targeted a provision that mandated new testing of laminated wood, a cheaper alternative to hardwood. (The California standard on which the law was based did not require such testing.)

But E.P.A. scientists had concluded that these laminate products — millions of which are sold annually in the United States — posed a particular risk. They said that when thin layers of wood, also known as laminate or veneer, are added to furniture or flooring in the final stages of manufacturing, the resulting product can generate dangerous levels of fumes from often-used formaldehyde-based glues.

Industry executives, outraged by what they considered an unnecessary and financially burdensome level of testing, turned every lever within reach to get the requirement removed. It would be particularly onerous, they argued, for small manufacturers that would have to repeatedly interrupt their work to do expensive new testing. The E.P.A. estimated that the expanded requirements for laminate products would cost the furniture industry tens of millions of dollars annually, while the industry said that the proposed rule over all would cost its 7,000 American manufacturing facilities over $200 million each year.

“A lot of people don’t seem to appreciate what a lot of these requirements do to a small operation,” said Dick Titus, executive vice president of the Kitchen Cabinet Manufacturers Association, whose members are predominantly small businesses. “A 10-person shop, for example, just really isn’t equipped to handle that type of thing.”

Photo
 
Becky Gillette wants strong regulation of formaldehyde. Credit Beth Hall for The New York Times

Big industry players also weighed in. Executives from companies including La-Z-Boy, Hooker Furniture and Ashley Furniture all flew to Washington for a series of meetings with the offices of lawmakers including House Speaker John Boehner, Republican of Ohio, and about a dozen other lawmakers, asking several of them to sign a letter prepared by the industry to press the E.P.A. to back down, according to an industry report describing the lobbying visit.

Within a matter of weeks, two letters — using nearly identical language — were sent by House and Senate lawmakers to the E.P.A. — with the industry group forwarding copies of the letters to the agency as well, and then posting them on its website.

The industry lobbyists also held their own meeting at E.P.A. headquarters, and they urged Jim Jones, who oversaw the rule-making process as the assistant administrator for the agency’s Office of Chemical Safety and Pollution Prevention, to visit a North Carolina furniture manufacturing plant. According to the trade group, Mr. Jones told them that the visit had “helped the agency shift its thinking” about the rules and how laminated products should be treated.

The resistance was particularly intense from lawmakers like Mr. Wicker of Mississippi, whose state is home to major manufacturing plants owned by Ashley Furniture Industries, the world’s largest furniture maker, and who is one of the biggest recipients in Congress of donations from the industry’s trade association. Asked if the political support played a role, a spokesman for Mr. Wicker replied: “Thousands of Mississippians depend on the furniture manufacturing industry for their livelihoods. Senator Wicker is committed to defending all Mississippians from government overreach.”

Individual companies like Ikea also intervened, as did the Chinese government, which claimed that the new rule would create a “great barrier” to the import of Chinese products because of higher costs.

Perhaps the most surprising objection came from Senator Boxer, of California, a longtime environmental advocate, whose office questioned why the E.P.A.’s rule went further than her home state’s in seeking testing on laminated products. “We did not advocate an outcome, other than safety,” her office said in a statement about why the senator raised concerns. “We said ‘Take a look to see if you have it right.’ ”

Safety advocates say that tighter restrictions — like the ones Ms. Boxer and Mr. Wicker, along with Representative Doris Matsui, a California Democrat, have questioned — are necessary, particularly for products coming from China, where items as varied as toys and Christmas lights have been found to violate American safety standards.

While Mr. Neltner, the environmental advocate who has been most involved in the review process, has been open to compromise, he has pressed the E.P.A. not to back down entirely, and to maintain a requirement that laminators verify that their products are safe.

An episode of CBS’s “60 Minutes” in March brought attention to the issue when it accused Lumber Liquidators, the discount flooring retailer, of selling laminate products with dangerous levels of formaldehyde. The company has disputed the show’s findings and test methods, maintaining that its products are safe.

“People think that just because Congress passed the legislation five years ago, the problem has been fixed,” said Becky Gillette, who then lived in coastal Mississippi, in the area hit by Hurricane Katrina, and was among the first to notice a pattern of complaints from people living in the trailers. “Real people’s faces and names come up in front of me when I think of the thousands of people who could get sick if this rule is not done right.”

An aide to Ms. Matsui rejected any suggestion that she was bending to industry pressure.

“From the beginning the public health has been our No. 1 concern,” said Kyle J. Victor, an aide to Ms. Matsui.

But further changes to the rule are likely, agency officials concede, as they say they are searching for a way to reduce the cost of complying with any final rule while maintaining public health goals. The question is just how radically the agency will revamp the testing requirement for laminated products — if it keeps it at all.

“It’s not a secret to anybody that is the most challenging issue,” said Mr. Jones, the E.P.A. official overseeing the process, adding that the health consequences from formaldehyde are real. “We have to reduce those exposures so that people can live healthy lives and not have to worry about being in their homes.”

A former member of the Boston Symphony Orchestra, Mr. Smedvig helped found the wide-ranging Empire Brass quintet.

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