This may come as a bit of a shock to you, but i'm not super into personal grooming.Like i understand soap and shampoo.But there's all this other stuff now, and i keep seeing references to ph balance everywhere.Ph balanced soaps, and shampoos, and deodorant, and makeup abound in supermarkets and drugstores.And i've even seen ph balanced water! we've talked a lot about balance over the last couple of weeks, and ph balance is related to the equilibrium state of a reversible reaction.You're probably also familiar with the ph scale, and you know that it has to do with acids and bases.
But what is ph exactly and why is it weirdly written with a lowercase 'p' and a capital 'h' and also, what about ph's alter ego poh the capitalization thing is probably the easiest to answer, 'cause there is no answer.No one really knows what the 'p' means.The danish chemist who came up with the term, a guy with the absolutely amazing name, sren srensen, never explained his reasoning.Some people think that it comes from some form of the word power, whether it's puissance in french, or maybe latin, pondus.
But it probably just came from a common habit chemist have of differentiating a test solution, labeled 'p', from a reference solution, called 'q'.But thinking of the 'p' as standing for power, does help us remember the meaning more easily.The 'h' part is even easier, it stands for hydrogen.Because hydrogen ions, or protons, are pivotal to the behavior of acids and bases, which is what ph describes.So you can think of ph as basically the power of hydrogen in a solution.The strength of the acid or base character of a substance.
And it all revolves around one very important point of focus, our old friend water.Theme music if you've been watching crash course chemistry from the beginning you've gotten the message that water is special in more ways than i can list, and ph is just one more of those ways.We normally think of water as a perfectly neutral substance, neither acidic nor basic, and that's true.But, as i've mentioned before, water can also function as an acid releasing hydrogen ions, also known as protons, and as a base consuming them.
How on earth is that possible in order to explain, we first have to understand what the ph of a substance really tells us.While chemically we say that ph represents the power of hydrogen in a solution, it's mathematically defined as the negative of the base 10 logarithm of the concentration of hydrogen ions in solution.Ok, so now that you're terrified, i'm here to help.So, yeah, logarithms can seem a little bit scary at first, but the ones that we're using here are super easy.And bonus, once you get familiar with them here, it'll be that much easier to understand them in math class.
So now that we got the scary mathematical definition, let's do the simplest mathematical definition.At any given moment, there will be a certain number of hydrogen ions in solution a very small number the concentration will be a number like one times 10 to the negative fifty moles per liter.That negative 5, is your base 10 logarithm.Take the negative of that, and you get the ph.5.Now let's get a bit more in to the weeds.The logarithm, or log, of a number is the exponent to which another number, called the base,.
Must be raised to produce the target number.So for base 10 logs, the base is 10.They're what we use most in chemistry, and they're really easy to understand, and also what we base scientific notation on.So as an example, the base 10 logarithm of one hundred is 2.Because 10 raised to the power of 2, or 10 squared, equals one hundred.Base 10 logs are so common that we often leave the subscript 10 off when we write it.Like if your calculator has a 'log' button, that's just for base 10 logs.
So what in the name of sren srensen does this have to do with face melting acids well i'm getting to that, and it all starts with waters crazy potential to act as both an acid and a base.Random changes in the tiny electrical fields around the atoms in water occasionally cause the molecules to break apart.Specifically a hydrogen ion, or proton, will break off from one molecule and attach itself to another one, forming a hydronium ion, h3o, and a hydroxide ion, oh.This is why water can act as both an acid and a base.
It's molecules can both release and accept protons.In this case, it's only interacting with itself.But water can interact in the same way with other acids and bases.Some times you'll see the hydronium ion written as a simple hydrogen ion, h, allowing the reaction to be written with only one water molecule.It's not technically accurate, but it's close enough to reality that it can be used to simplify things.So when we say that the ph is the negative log of the hydrogen ion concentration.Yeah, we actually mean hydronium ion concentration.
Just another thing that early scientists got a little wrong and now we have to live with.Anyway, this dissociation of water is a reversible reaction.And in fact, the ions always reform in to water within a tiny fraction of a second.But it's happening all the time constantly.In your bottled water, in the water inside your cells, and in the ocean.Always.However, at any given instant only a tiny number of molecules are dissociated ions.In fact, the exact number of these molecules is well known to chemists.
It's the equilibrium constant for this reaction.And because it's such a special reaction, it has it's own name the water dissociation constant, or kw.Kw is equal to one point zero times 10 to the negative fourteenth.The formula for kw is set up like any equilibrium constant, concentrations of products over concentrations of reactants, all raised to the exponents based on the coefficients of the balance reaction.There is however one difference.Because the ions represent such a tiny proportion of the total mass, the water itself is essentially pure.
And pure substances, because they don't have concentrations, aren't included in equilibrium calculations.So the formula for kw becomes simply the hydronium ion concentration times the hydroxide concentration.According to the balanced equation for the dissociation of water, hydronium and hydroxide are formed at a 11 ratio, so their equilibrium concentrations must be equal.That means if we call the concentration of h3o, for example 'x', then the concentration of oh must equal 'x' as well.So the formula for the dissociation constant 1.0 x 1014 simplifies even further to x times x, or x squared.
Suddenly, it's crazy easy.The equilibrium concentration of each ion is just the square root of 1.0 x 1014.Touch one key on the 'ol calculator, and hello both concentrations equal 1.0 x 107 moles per liter in equilibrium.The ph then, is simply the negative log of that, which is 7.This my friends, is the basis of the ph scale.Water is neutral, so 7 is the center of the scale.And i can prove it too.This is a strip of paper that's been infused with a chemical called litmus.
Litmus is a ph indicator, a chemical that turns different colors at different phs.There are many different indicators, with many different colors, but we'll talk more about those next week.For now, just know that litmus paper turns pink in acids, blue in bases, and a sorta light purple when it's neutral.But one thing you need to remember about the ph scale, because ph is calculated from a negative logarithm, it turns everything backward.When the hydrogen ion concentration goes up, the ph gets lower.For instance, if a little acid, such as vinegar, were added to the water,.
The concentration of hydronium ion might rise to say, 1.0 x 104 moles per liter.Which is a thousand times more than before.That concentration would push the ph down to 4.On the other hand, a base, such as ammonia, would consume a lot of hydrogen ions if it were added to the water.If the hydrogen ion concentration drops to 1.0 x 1011, a thousandth of the equilibrium concentration, the ph would be eleven.As you can see, the logs turn out to be a mathematical shorthand, that saves us from dealing with very huge or very tiny numbers.
The ph scale then is normally written from 0 to 14.With numbers below 7 representing acids, and numbers above 7 representing bases.It could also below zero or above 14, but that only happens in super extreme cases, that you are very unlikely to encounter.At least i hope.As with like hydrochloric or nitric acid, which ionize strongly, sometimes even completely.Thus releasing a lot of protons, are called strong acids.Because they raise the hydrogen concentration a lot, they also generally have very low phs.Weak acids, like citric acid, dissociation incompletely,.
Releasing much smaller amounts of hydrogen ions, and therefore they usually have higher phs.Generally considered in like the 4 to 6 range.Strong bases meanwhile, like sodium hydroxide, consume large amounts of hydrogen ions leaving the concentration very low, so they 10d to have very high phs.Weak bases, like sodium bicarbonate baking soda, consume much less, and generally have phs in the 811 range.Neutral ph is technically just 7.0, but in a more practical sense, it's usually considered to be between 6 and 8.So if ph is based on the concentration of hydrogen, that is hydronium ions,.
What about the concentration of hydroxide ions just as we can calculate the ph of a substance from it's hydrogen ion concentration, we can calculate the poh.The negative log of the hydroxide concentration.This is easy because kw never changes.Although the concentrations of hydrogen and hydroxide are only equal in pure water, or perfectly neutral solutions, the product of the 2 concentrations always equals 1.0 x 1014 in any aqueous solution.So like orange juice, which is really just an aqueous solution of sugar and citric acid and a few other things,.
Say the hydrogen concentration in your oj is 3.2 x 104 moles per liter.Just for the fun of it, let's go ahead and calculate what the ph is at that point, which turns out to be 3.5.But we can also use the kw and the hydronium ion concentration to do a very simple division problem and find the hydroxide concentration.It works out to 3.1 x 1011 moles per liter.Once we have the concentration we can take another step, we can find the poh of the solution which is similar to the ph, simply the negative log of the oh concentration.
The poh in this case is 10.5.And now for a tip that's just more awesome and cooler than an ice cream corn dog, the sum of the ph and the poh is always 14.In the example we just did, the ph was 5.4 and the poh was 8.6, and yeah you add those together 14! surprise! ok, maybe that's only cool to me.But that's never stopped me before, i love this stuff! and next week, i hope to really bend your mind by showing you how to make the ph of a solution hold steady,.
Even if you dump a strong acid or base in it.In the meantime, thank you for watching this episode of crash course chemistry.If you paid attention, you learned how pure water ionizes to form hydronium and hydroxide ions in reversible reactions.And you learned about the equilibrium constant for that reaction, which has a special name the water dissociation constant.You learned some examples of acids and bases and neutral substances, as well as why some acids and bases are called strong and others are called weak.You learned about logarithms and how you can use them to calculate the ph of a substance.
Understanding Acid Alkaline And The Many Myths On PH
Understanding acid alkaline and the many myths on ph,Find your body type bodytypequiz how important is maintaining the acidity in your body dr berg explains what ph level means in your body and. What is the ph scale chemistry for all fuseschool,Learn the basics about the ph scale universal indicator and litmus paper indicators tells if something is acidic alkaline or neutral indicators are substances that. Chemistry acids bases fundamentals 5 of 35 why is water a neutral substance,Visit ilectureonline for more math and science lectures in this tutorial i will talk about the concept of what is neutral especially water.
Acids and alkalis,Acids and alkalis acids have been known for centuries and have a sour taste in your diet you may have tasted many sour substances examples include citrus. Measuring acidity a science bite experiment to try at home,Try our science experiment measuring acidity where you will prepare your own acid indicator by extracting a pigment from a red cabbage and use it to look. 183 deduce whether salts form acidic alkaline or neutral aqueous solutions hl ib chemistry,If you know if the acid and base used to make the salt you can judge its ph the ph will be related to that of the stronger reactant explaining this requires you to.
Basics of ph iitutor,Siitutor learn the words acidic alkaline basic and neutral you will learn to look at ph charts how ph is measured examples of everyday life.
How to use ph test strips for measuring acids bases alkaline,Envcleanup 24 hour hazmat response 866 h2ospill visit our blogenvcleanupblog linkedin. Acids and alkalis,Acids and alkalis learning objectives to know that solutions can be sorted by whether they are acid alkali or neutral tounderstand that an alkali reacts with an. The alkaline myth hype the acidalkaline truth exposed,Markusnews dont drink alkaline water until you watch this learn the truth behind the big alkaline hype and learn why acids are not bad in fact. 83 distinguish between acidic neutral or alkaline solutions using ph sl ib chemistry,Neutral solutions are ph 7 below ph 7 is acidic and h is greater than oh above ph 7 is alkaline and therefore h is less than oh.
Ph and poh crash course chemistry 30,You can directly support crash course atsubbablecrashcourse subscribe for as little as 0 to keep up with everything were doing also if you. Testing acids bases on litmus paper,Wondering what to do with litmus paper dont write on it but instead drop a drop of solution on both red and blue litmus paper in order to determine the ph. Science experiment home substances in ph scale,This is another science experiment it is connected with chemistry these are every day materials and their ph based on it they have different colour when they.
Acid base or neutral 3a,Determining whether any given compound is acidic basic or neutral. Acidbase home lab 61310 chemistry project,So instead of another train tutorial this week i thought why dont i just upload my chemistry project tutorial for something different it involves boiling cabbage. What is alkaline water is it the same as alkaline ionized water,Learn more about alkaline water drinkingwaternobswater the buzz about alkaline water is not accurate additional factors make ideal benefits of.
Make Your OWN PH Indicator From Red Cabbage
Make your own ph indicator from red cabbage,Hello everyone today we will conduct an experiment that anyone can repeat in their home we will make a universal ph indicator from a red cabbage first we. Do it yourself soil test measure ph,Thanks for the views comments and support please like share comment and subscribe more gardening tutorials. How to make ph pasta,Welcome to sunday science with hazel and nat where we do simple experiments with items that you can find around your own home in the run up to british.
Creative idea cleaning product cleaning wall and ceiling,Creative idea cleaning product cleaning wall and ceiling cleaning agents are substances usually liquids powders sprays or granules used to remove dirt. Alkaline foods and the power of blending,To blend green vegetables is a quick and effective way to alkalize your body which means bringing plenty of organic minerals vitamins and vital substances into. Difference between alkali and acid,Alkali wikipedia the free encyclopedia a href urlq answersyahoo question index i am stuck on my homework and i need to know what the answer to my.
Acids bases and ph,Paul andersen explains ph as the power of hydrogen he explains how increases in the hydronium ion or hydrogen ion concentration can lower the ph and. Alkaline water information by shri satpal ji 21th nov 2015 hindi,Best alkaline water benefits let us now find out about the 10 best benefits of drinking alkaline water 1 antioxidant alkalized water is believed to be a powerful.