Physically, acids have a sour taste, are soluble in water, turn blue litmus paper red, are corrosive, have pH values less than 7 and conduct electricity. These physical properties of acids are a byproduct of the acids' chemical properties. Acids can be solutions or pure substances and can be either solid, liquid or gaseous in nature.
Acids are defined as substances that increase the concentration of hydrogen atoms, or more accurately, hydronium atoms (H30), in water. This ionization of acid, which is typical of all salts, is the reason acids conduct electricity. The pH values are defined as the negative logarithm of the concentration of hydronium atoms in a solution; thus acids give a pH value less than 7 because hydronium concentrations are greater than 10^-7 moles per liter. The strength of an acid, and thus its corrosiveness, is determined by how much an acid ionizes, or dissociates, into hydronium atoms in water, with strong acids dissociating completely and weak acids only partially. These hydronium atoms chemically react with metals and living tissue. This corrosive property is useful in the human body, as the acid in the stomach aids in the digestion of food. Weak acids are also used as additives in food to infuse a sour taste.Learn More
Acids share several common characteristics and properties, including sour taste and corrosion to all metals. These characteristics distinguish acids from bases, which culminate the second broad class of chemical substances encountered in daily life. Acids vary widely in purpose and structure; some, such as lemons and citrus fruits, are edible and important sources of nutrition, while others exist as toxic chemicals.Full Answer >
Water has numerous physical properties, including the color, surface tension and adhesion. There are far more physical properties than chemical properties. This is partially due to water taking so many forms, such as ice or steam; each form of water has different properties.Full Answer >
The pI is the pH at which an amino acid molecule exists in an uncharged state. The pI of alanine is 6.11, while that of histidine is 7.6. The pH of the surrounding environment of a molecule affects its net charge.Full Answer >
The pKa for phosphoric acid is 2.15 for the first dissociation, 7.20 for the second dissociation and 12.35 for the third dissociation. These values are based on an ambient temperature of 25 degrees Celsius, and are known as Ka1, Ka2 and Ka3, respectively.Full Answer >