The definition of a phd extract from: how to get a phd (open university press) by estelle phillips & derek pugh nowadays this does not mean that becoming a lecturer is the only reason for taking a doctorate, since the degree has much wider career connotations outside academia and many of those with doctorates do not have academic teaching. A solution with a ph 70 is neutral, one with a ph of more than 70 is alkaline, one with a ph lower than 70 is acid it is a convenient way of expressing the acidity or alkalinity of solutions, particularly of contact lens buffer solutions.
Definition of ph about transcript introduction to ph and the ph scale examples of calculating ph of pure water, bleach, and orange juice google classroom facebook twitter email acids, bases, and ph autoionization of water arrhenius definition of acids and bases what does that mean.
Answer: ph is the negative log of hydrogen ion concentration in a water-based solution the term ph was first described by danish biochemist søren peter lauritz sørensen in 1909 ph is an abbreviation for power of hydrogen where p is short for the german word for power, potenz and h is the element symbol for hydrogen.
Its nominal value of ph = 74 is regulated very accurately by the body if the ph of the blood gets outside the range 735 to 745 the results can be serious and even fatal if you measure the ph of tap water with a ph meter, you may be surprised at how far from a ph of 7 it is because of dissolved substances in the water.
In the meaning defined above see words from the same year ph abbreviation definition of ph 1 pinch hit 2 public health 3 purple heart see ph defined for english-language learners ph defined for english language learners ph noun medical definition of ph:. The soil ph can also influence plant growth by its effect on activity of beneficial microorganisms bacteria that decompose soil organic matter are hindered in strong acid soils this prevents organic matter from breaking down, resulting in an accumulation of organic matter and the tie up of nutrients, particularly nitrogen, that are held in the.
Once you get your soil ph into an acceptable range, you will need to reapply either lime or sulfur on a regular basis, to keep it there this is best done in the fall or off season, so that the amendment has time to work its way into the soil slowly, without harming plant roots.
Understanding ph and orp when talking about water, its ph value is related directly to the ratio of positively charged hydrogen ions [h+] and negatively charged hydroxyl ions [oh-] when water has an equal concentration of h+ ions and oh- ions, it is said to be neutral (ph=7. However, ph measurement is complicated by the chemical properties of seawater, and several distinct ph scales exist in chemical oceanography as part of its operational definition of the ph scale, the iupac defines a series of buffer solutions across a range of ph values (often denoted with nbs or nist designation.