what is the life of pH Electrode ?
958818
typical pH electrode life is expected to be one year from the date of manufacture for most warranty purposes. They do depend on application and application variances (i.e. how stable the solution being tested is.. amount of variance, temperature , etc). these factors all shorten electrode expected life. As far as having 10 year working electrodes.. i have heard of this, but I wouldnt count on the quality of these elctrodes over a wide pH range. They should be tested and verified. They are most likely indicating near correct pH in a vary stable solution and not very responsive over a large range ( in other words they're currently zeroed into reading correctly and wont if the solution varies a lot). The failure rate after 2 months maybe the case with electrodes that have been on a shelf for long periods beore being commissioned for use or less likely but I have seen it - a bad "batch" of electrodes you received from stock. Consult your supplier for support. If these are being used in low temperature conditions (under say 45 degrees F) you may require thermal compensation to read correctly over the 32-45 degree range.
846112
corrosive=basic, \nbelow 7 on the pH scale is acidic and above is basic, \nOH- ions are basic, H+  ions are acidic, \nlitmus paper is blue when something is basic and red when something is acidic, \nand electrolytes are acidic because they contribute H pos ions in a chemical reaction.
224478
The pH of a solution can be measured by titration, which consists of the neutralization of the acid (or base) by a measured quantity of base (or acid) of known concentration, in the presence of an indicator (a compound the color of which depends on the pH). The pH of a solution can also be determined directly by measuring the electric potential arising at special electrodes immersed in the solution.
133368
Normal ph level is 7.35-7.45
1095569
check this link-- http://www.orgsyn.org/orgsyn/prep.asp?prep=cv6p0468.\n\ninstead of Me use Ph
814606
pH samples need to be analyzed immeditely for regulatory purposes.  There is no holding time.  They must be test ASAP.
936680
1.)   The battery contains 4 amp hours of electrons.  This means it can be drained at the rate of 1 amp per hour for 4 hours.\n2.)   So, if you are only draining it at the rate of 1//4 amp per hour it will last 4 times as long or 16 hours.\n3.)   Just think of a battery as a bucket full of water e.i. The slower you pour it out the long it lasts.
951376
Yes, they can deteriorate with time especially if not kept in a fridge in a sterile container.\nPhosphate buffers are amongst the worst because they get contaminated easily and grow stuff which will most likely spoil the experiment.\n\nThe best way to overcome this is to always make fresh buffer with each experiment :)
845596
The pH buffers used in a lab experiment can go "bad" at different rates depending on the way they're stored. If your buffer is always stored in a closed container, then the contamination is usually pretty low and the buffer can last for a long time. However if your buffer is constantly exposed to open air and moisture, the pH of your solution can vary quite a bit. I'm not sure if you are familiar with the effect of boiling "tap" water, but boiling the water gets rid of carbonic acid in the solution, similar to the acidity found in a soft drink. So over time, if a buffer is exposed to air, the buffer will tend to become more acidic if no other factors (contamination by other careless people in the lab for example :P) are present. Hope this helps!
169778
What I think you're talking about are how acidic and how basic something is according to the pH scale.  Maybe?  \n\nWe us the pH scale to describe how acidic or how basic a solution is. pH stands for potential of hydrogen. It's numbered from 1 to 14--increasing in basicity.\n\nHydrogen and hydroxide ions are very reactive, and the proper balance of these ions is critical for the proper functioning of chemical processes within an organism.\n\nA compound that donates hydrogen ions to solutions is called an acid.  Examples of an acid would be something like lemon juice and tomato juice.  Even the gastric juice inside of your stomach.\n\nA base is a compound that accepts hydrogen ions and removes them from solutions.  Examples of a base would be something like bleach or oven cleaner.\n\nThe increasing acidity means there's a higher concentration of H+.  The decreasing basicity means there's a lower concentration of H+.  \n\nPURE WATER is neutral----or 7 on the pH scale.\n\nHope this helps. :o)
982524
7.\nclick here:http://en.wikipedia.org/wiki/PH
1151718
You can perform electrolysis of water (or electrolysis of dilute sulphuric acid as it is called). The apparatus used is a Hoffman's voltmeter, with platinum electrodes. On passing an electric current, H+ and OH- ions in the water molecule dissociate and migrate to the corresponding electrodes.\n\nAt cathode: H+  + e- --------> H(g)\nH(g) + H(g) --------> H2(g)\n\n2 volumes of hydrogen are released at cathode.\n\nAt anode: OH- (aq) -----------> OH(g) + e-\nOH(g) + OH(g) -----------> H2O + O(g)\nO(g) + O(g) -------------> O2(g)\n\n1 volume of oxygen released at anode\nThus hydrogen and oxygen are released at a ratio of 2:1
717750
Supposedly, micro combination pH electrodes can measure pH with as little as 10 microliters of sample.  I've never used one, so I can't tell you how accurate they are or how much they cost, but it might be worth looking into.
731164
pH: pH is a measure of the acidity or hydrogen ion concentration of a solution. It is measured on a scale of 0-14 with pH values below 7 being acidic, values above 7 being basic and a value around 7 is neutral. As the pH drops into the acidic range an enzyme tends to gain hydrogen ions from the solution. As the pH moves into the basic range the enzyme tends to lose hydrogen ions to the solution. In both cases the changes produced in the chemical bonds of the enzyme molecule result in a change in conformation that decreases enzyme activity.\n\nHope this helps :)
882738
The pH scale is logarhytmic- it goes up by powers of ten.\n\nFrom pH 2 to pH 1, there is 10 times the H+ concentration.\nFrom pH 3 to pH 1, there is 100 times the H+ concentration.\nAnd so on.\n\nTo answer your question, the pH will become more acidic by 3 points.
804153
At high pH values (>10), the Hydroxide ion in solution takes protons from the phenolphthalein indicator, forming an ion and water.  The -2 ionic form of phenolphthalein then rearranges the electronic structure to form the characteristic pink color.\n\nSee the wikipedia article for more.
694693
The only difference in a portable is that it has a battery pack instead of or in addition to a power cord.\n\nThe basic phenomenon upon which the pH meter operates is the development of an electrical potential (voltage) by a chemical reaction in an electrochemical cell. Such a cell consists of two dissimilar half cells, different in materials or concentration, separated by a semipermeable membrane. This allows for the contact of the two solutions but does not allow mixing and hence direct reaction of the substances in the two half cells. The voltage is measured across the two electrodes in the half cells.\n\nThe system consists of a pH sensor, pH Half Cell, whose voltage varies proportionately to the hydrogen ion activity of the solution, and a reference electrode, Reference Half Cell, which provides a stable and constant reference voltage.\n\nThe pH electrode consists of a thin membrane of Hydrogen sensitive glass blown on the end of an inert glass tube. Because this is a special type of glass and very thin, the bulb is very fragile and great care must be exercised in handling it.\n\nThis tube is filled with an electrolyte, and the signal is carried through Ag/AgCL wire. This is a pH half Cell.\n\nA similar system, but without using a Hydrogen sensitive glass, is used as a reference. A small filter (diaphragm) connects this tube to the external liquid. This system is called a Reference Half Cell.\n\nIt is very common to find pH meters which are fitted with only a single combination electrode. As the name implies, a combination electrode is a combination of the glass electrode and the reference electrode into a single probe. The probe is constructed with the reference surrounding the glass electrode. The primary advantage to using a combination electrode is the ability to measure the pH of a smaller volume of sample or a sample in a container with a restricted opening. The main disadvantages to using a combination electrode are the more limited selection of internal elements (most have only a silver-silver chloride internal reference) and the higher cost.