Complicated, hard-to-heal wounds are a growing medical problem and there are currently only two drugs approved with proven efficacy. In a new study on humans, researchers at Uppsala University show that treatment with a specific ...
May 30, 2023
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Two plants native to Northern Australia could have significant medicinal potential in the prevention and treatment of diseases, according to two studies by a Charles Darwin University (CDU) Ph.D. candidate.
May 29, 2023
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When it comes to our health, most of us have heard of prebiotics and probiotics and know something about their benefits to our digestive system (even if it's hard to tell them apart), but what about postbiotics?
May 25, 2023
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Cancers often release molecules into the bloodstream that pathologically alter the liver, shifting it to an inflammatory state, causing fat buildup and impairing its normal detoxifying functions, according to a study from ...
May 25, 2023
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The Mays Cancer Center at The University of Texas Health Science Center at San Antonio recently conducted a clinical trial combining two drugs in patients with recurrent, high-grade glioblastoma (GBM). The Mays Cancer Center, ...
May 23, 2023
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Excess sugar hampers cells that renew the colon's lining in a mouse model of inflammatory bowel disease (IBD), according to a new study by University of Pittsburgh scientists.
May 22, 2023
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Doctors are one step closer to having a risk biomarker to alert them to which of their pediatric stem cell transplant patients are likely to experience a potentially deadly side effect called sinusoidal obstruction syndrome ...
May 22, 2023
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Genetic alterations that give rise to a rare, fatal disorder known as MOGS-CDG paradoxically also protect cells against infection by viruses. Now, scientists at the Lewis Katz School of Medicine at Temple University have ...
May 19, 2023
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A team of researchers have discovered that a mutation in a ribosomal protein found specifically in heart and skeletal muscle leads to impaired cardiac contractility in mice.
May 19, 2023
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Researchers have identified various genes whose expression in the brain before birth may affect the risk of developing a range of mental illnesses during childhood. The team, which was led by investigators at Massachusetts ...
May 18, 2023
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An acid (from the Latin acidus/acēre meaning sour) is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red. Chemicals or substances having the property of an acid are said to be acidic.
Common examples of acids include acetic acid (in vinegar), sulfuric acid (used in car batteries), and tartaric acid (used in baking). As these three examples show, acids can be solutions, liquids, or solids. Gases such as hydrogen chloride can be acids as well. Strong acids and some concentrated weak acids are corrosive, but there are exceptions such as carboranes and boric acid.
There are three common definitions for acids: the Arrhenius definition, the Brønsted-Lowry definition, and the Lewis definition. The Arrhenius definition states that acids are substances which increase the concentration of hydronium ions (H3O+) in solution. The Brønsted-Lowry definition is an expansion: an acid is a substance which can act as a proton donor. Most acids encountered in everyday life are aqueous solutions, or can be dissolved in water, and these two definitions are most relevant. The reason why pHs of acids are less than 7 is that the concentration of hydronium ions is greater than 10−7 moles per liter. Since pH is defined as the negative logarithm of the concentration of hydronium ions, acids thus have pHs of less than 7. By the Brønsted-Lowry definition, any compound which can easily be deprotonated can be considered an acid. Examples include alcohols and amines which contain O-H or N-H fragments.
In chemistry, the Lewis definition of acidity is frequently encountered. Lewis acids are electron-pair acceptors. Examples of Lewis acids include all metal cations, and electron-deficient molecules such as boron trifluoride and aluminium trichloride. Hydronium ions are acids according to all three definitions. Interestingly, although alcohols and amines can be Brønsted-Lowry acids as mentioned above, they can also function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms.
This text uses material from Wikipedia, licensed under CC BY-SA
