Search results
Results From The WOW.Com Content Network
Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. [ 1] pH is defined as the negative logarithm (base 10) of the activity of hydronium ions ( H+.
Soil acidification. Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid, such as nitric acid, sulfuric acid, or carbonic acid. It can also be a compound such as aluminium sulfate, which reacts in the soil to release protons.
At 25 °C (77°F), solutions with a pH less than 7 are acidic, and solutions with a pH greater than 7 are basic. Solutions with a pH of 7 at 25 °C are neutral (i.e. have the same concentration of H + ions as OH − ions, i.e. the same as pure water). The neutral value of the pH depends on the temperature and is lower than 7 if the temperature ...
Potentially Hazardous Food. Potentially Hazardous Food is a term used by food safety organizations to classify foods that require time-temperature control to keep them safe for human consumption. A PHF is a food that: Contains moisture – usually regarded as a water activity greater than 0.85. Contains protein.
A solution of sodium acetate (a basic salt of acetic acid) and acetic acid can act as a buffer to keep a relatively constant pH level. This is useful especially in biochemical applications where reactions are pH-dependent in a mildly acidic range (pH 4–6).
Pollution. Acid rain is rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions (low pH ). Most water, including drinking water, has a neutral pH that exists between 6.5 and 8.5, but acid rain has a pH level lower than this and ranges from 4–5 on average. [ 1][ 2] The more acidic ...
Ocean acidification is the ongoing decrease in the pH of the Earth's ocean. Between 1950 and 2020, the average pH of the ocean surface fell from approximately 8.15 to 8.05. [ 2] Carbon dioxide emissions from human activities are the primary cause of ocean acidification, with atmospheric carbon dioxide (CO 2) levels exceeding 410 ppm (in 2020).
A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH ( acidity or basicity) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. [ 1] Hence, a pH indicator is a chemical detector for hydronium ions (H 3 O +) or hydrogen ions (H +) in the ...