pH Levels

pH levels are the measure of activity of hydrogen.

5,354 Questions
pH Levels

What is the pH level of chilli?

Technically, pH is a measure of the hydrogen ion concentration in water. The lower the pH, the more hydrogen ions it has and the more acidic it is. In water that has exactly the same number of hydrogen ions and hydroxide ions, the pH is neutral (7.0). Tomatoes and tomato paste have a pH of about 4.0 to 4.5. Other ingredients in chili such as beef and beans would not contribute much to the pH, so the final pH of chili is probably similar to the tomatoes, or perhaps slightly higher due to dilution effects from water.

While it is common to think that the "hot" taste of peppers is due to an acid pH, the usual culprit (or 'prize' to some) is one of several molecules inherently in peppers, the most-common being capaisin, which was isolated in the late 1970's, and now is used in pain relievers.

pH Levels

Why pH for eye drops is 7.4?

that is the pH of the fluid around your eye. Very few solutions are actually 7.

pH Levels

What is the pH of whey?

It varies based on how it's processed. Sweet whey is about 6.5 and acid whey is about 4.5. Most powdered whey used in supplements is sweet whey.

pH Levels

What is the pH level of handyandy?

Handy Andy looks like a person, he probably has multiple pH levels.

pH Levels

What is the pH of jejunum?

Between 7-9

pH Levels

What the safe pH of the soap?

pH 5.5 which is about the same pH as the skin.

Swimming Pools
Pool Care and Cleaning
pH Levels

How do you lower the alkalinity of a pool with muriatic acid without affecting the pH?

There is NO way to lower TA without lowering pH. Slugging acid in a pool with the pump off will have EXACTLY the same effect as walking the acid around the pool AND can cause damage to pool surfaces. When you add acid you convert bicarbonate (TA) into carbonic acid. This action lowers both pH and TA. Carbonic acid is basically CO2 dissolved in water. If you let the CO2 gas off the pH will rise (since the amount of carbonic ACID) in the water is lessened) and the TA will stay where it is (since we cannot form more bicarbonate).

To lower TA safely without causing damage to pool surfaces:

1. drop the pH to 7.0 and no lower with acid ( use an acid demand test in a good test kit to do this)

2. aerate the water to gas off CO2. (fountains, waterfalls, turning the eyeballs upward in the returns to break the water surface, having a 'splash party' in the pool, or anything else that disturbs the water will work. ) The aeration will cause the pH to rise. When the pH is above 7.4 test the TA. (it won't move much at first but will eventually start to move if it is very high). If the TA is still too high repeat from step 1. When the TA is where you want it you are done.

To sum this up:

The main component of TA is the bicarbonate in the water

The act of adding the acid lowers BOTH the pH and the TA by converting bicarbonate into carbonic acid (basically carbon dioxide dissolved in the water). It lowers pH much faster than it lowers TA

Allowing the carbon dixoide created by lowering the pH to gas out of the water causes the pH to rise again because the amount of carbonic ACID in the water decreases. However the amount of bicarbonate does not increase so neither does the TA.

Acids and Bases
pH Levels

What is the pH of stomach acid?

The pH of stomach acid is about 2 and strong enough to burn a hole in a rug.

pH Levels

What is the pH of coffee?

On the web they say anywhere from 5.2 to 6.9. It depends on the type of coffee and where the beans came from. Soils from different regions have different pH levels.

Vital Signs
pH Levels

What is a normal blood oxygenation level?

90-100% is normal, although this may vary by age, co-existing medical conditions and altitude.

J. DeLaughter, DO

lmnurse added - In some older patients, especially those with COPD you can see levels as low as 85% on room air.

23babygirl added - It does not have to be an older patient to see this. It can be in ANY patient with active COPD.

fire61890 added- the actual normal oxidation level is 96%-100% lower than 96 is normal for someone with COPD or someone who smokes a lot

Units of Measure
Acids and Bases
pH Levels

What is pH and what does it measure?

The pH is a measure of how acidic or basic(alkaline) an aqueous solution is.

Pure water is neutral, with a pH = 7. Things with a pH <7 are acidic, and things with a pH >7 are basic.

The theoretical pH of an aqueous solution is defined this way:

pH = -log10 [H3O]

Related Information:

The pH approximates the negative logarithm, base 10, of the Hydronium ion (H3O+) molar concentration of an aqueous solution. It's an indicator of the relative acidity or basicity (alkalinity) of the solution.

What makes a solution acidic is the amount of H3O+ in it. A highly acidic solution will have a high concentration of H3O+, and so it will have a low pH. A basic solution has a very low concentration of H3O+, and so it has a high pH. Note that H3O+ and H+ really refer to the same thing, but H+ doesn't actually exist by itself in water: it immediately combines with an H2O molecule to form H3O+ instead.

Substances with very high, or very low, pH are dangerous to human hair, eyes, and skin.

Examples: pH of common substances are:

Stomach acid -- 1

Lemon juice -- 2.2

Pure water -- 7

Milk of magnesia -- 10.5

pH Levels

What is the pH level of a white potato?

pH is the measure of whether a solution is alkaline or acidic.

Potatoes have a common pH level of about 5.0 to 5.5

this means they are pretty acidic.

Elements and Compounds
pH Levels

Is a sodium level of 120 low?

120 is a very low number for sodium, and may result in seizure activity. The normal range for sodium is 135 to 145 mEq/L (millequivelents per liter.)

Just to add to this, my sodium is 122 and my doctor said that this is very near critical. If you have a blood sodium level at 120 your doctor should be taking steps to correct it and find the cause.

pH Levels

What is the pH of Butanone?

I got a pH of 7.

Fruit and Vegetable Juices
pH Levels

What is the PH level of mango juice?

it is nearly between 3.4 - 4.6.

pH Levels

What is the pH of vinegar?

Vinegar is acidic in nature as it is a solution of acetic acid. The exact pH of vinegar depends upon how much acid is present, but most commercial distilled white vinegars contain 5-10% acetic acid and have a pH roughly around 2.40 - 3.40.

The textbook pH of vinegar is 2.5.

PH Number Of Vinegar Is PH 3

the pH number of vinegar is 2.0 to


vinegar 3.40

pH Levels

What is the pH of dextrose?

Dextrose is a solid so it doesn't really have a pH until it is in solution. Once it is in solution, it would depend on what the solvent was and the concentration of the dextrose. So it could range greatly, but most are kept around 6.4.

pH Levels

What is the pH of listerine?


Acids and Bases
pH Levels

How do you find the pH of a weak acid solution?

NOTE: This is NOT the same as finding the pH of a STRONG acid solution. See the Related Questions links at the end of this answer to find out the difference between a strong acid and a weak acid, and if you have a strong acid, follow the link to find the pH of a strong acid solution (it is much easier!)

This is long and boring so i will simplify it. Usually you use a universal indicator and a ph scale. You can get those things from shops like bunnings (soil ph level)

To determine the pH of a weak acid solution you must know two things: you need the concentration of the acid in the solution, and you need the Ka of the acid (or equivalently the pKa, which you can use to calculate the Ka).

First, we must write the equation of the acid dissociation in water. Let's use a generic acid that we'll call 'HA.' When it dissociates, it will form H+ and A- (A- is called the conjugate base of the acid HA).

HA + H2O --> H3O+ + A-

Note: When describing acids, some people use H+ and some people use H3O+, but they are basically equivalent. It is a bit more accurate to use H3O+ because that is what is actually present in the solution, so I will use it here.

Because this is a weak acid, this reaction will go to some equilibrium value, and this will be described by the equilibrium constant, Ka. The equilibrium product for this reaction is found by taking the concentration of the products and dividing them by the concentration of the reactants (with the concentration of each specie raised to its respective coefficient in the balanced reaction). So at equilibrium, we have:

Ka = [H3O+] [A-] ÷ [HA] - where the square brackets mean concentration (for instance 'N]' means 'the concentration of N').

Note: H2O is NOT included in the equilibrium product even though it is a reactant because its concentration in dilute solutions is not changing more than 0.1%]

If you are given the pKa instead of the Ka, use this formula to find the Ka:

pKa = -log10 Ka or inversely Ka = 10-pKa

OK -- now how do we solve? To do this, we must set up what is sometimes called an 'ICE' chart, for Initial-Change-End. Because of the formating constraints, it will be hard to show that here correctly, but I will describe it. Write the balance equation, and underneath it we're going to write three rows of information

In the first row, called 'Initial,' write the concentration of HA, H3O+ and A-initially (in other words before equilibration). Well, that's easy. Initially, we have zero concentration of H3O+(*) (cf. note at the end) and zero concentration of A-, and the amount of HA is however much was specified in the question (in units of molar (M), or moles per litre). To keep this explanation general, let's call the number which is the starting concentration of HA "[HA]initial." This is our "initial" row of data.

In the 2nd row, the "Change" row, we're going to mark the change in the concentration of each specie. Well, we don't know that! So we're going to use a variable, and let's call it "x." Now, the only way to make H3O+ and A- is from an HA molecule that dissociated. So we know that however much A- is formed, we must have made exactly as much H3O+ at the same time. And we also know from the stoichiometry of the balanced reaction, that for each mole of A- formed, one mole of HA was reacted.

So, let's say that the change in [H3O+] increase by 'x' (note that it has to increase -- it started at 0 and you can't have a negative concentration!), then the [A-] must increase by exactly the same amount, so also 'x'. Now that means that [HA] decreased by the same amount... 'x'... except because it decreased, we make it negative, and write '-x'.

Now we'll fill in the 3rd row, the "End" row. To find this, we just added up the first two rows. So, in the end,

[H3O+] = 0 + x = x (*) (cf. note 1 at the end)

[A-] = 0 + x = x

The end value of [HA] is going to be whatever it started at minus x. So that can be written as: [HA]end = [HA]initial - x

Now we can solve.

Ka = [H3O+] [A-] ÷ [HA] = x * x ÷ ( [HA]initial - x )

To find the pH, we want to solve for [H3O+], which happens

to equal 'x'. (*) (cf. note 1 at the end)

Rearranging, we have:

x2 - ( Ka = ([HA]initial - x) ) = 0

If the acid is fairly weak and/or not too diluted(**) (cf. note 2 at the end), we can say that not much will dissociate, and can make the following approximation to simplify the math:

[HA]initial - x = [HA]initial

So now, using that, we can write:

x2 - (Ka*[HA]initial) = 0 or x2 = (Ka*[HA]initial)

And we know what both Ka and [HA]initial are from the beginning, so just multiply them together and take the square root to solve for 'x'.

The last step is to find the pH. The pH is defined like this: pH = -log10[H3O+]

It turns out that the value of 'x' is the same as [H3O+] because of the way we set up the problem. So to find the pH, just take the negative of the logarithm (base 10) of 'x'.

pH = -log10 (x)

And you're done!

Note 1:

(*) Actually this is not the full truth: Water itself initially contains 10-7 protons.

Thus exactly [H3O+] = 10-7 + x which is approximately equal to x if x>>10-7, for example x= [H3O+]calculated=10-6 or bigger.

So the outcome of this calculation is still usable if -log10 (x) = [pH]calculated =< 6.

If not, the pH can be fairly approximated to be between 6 and 7,because it should clearly never exceed value 7 (Remember: Water itself initially contains 10-7 protons!)

Note 2:

(**) Otherwise one has to solve the quadratic equation:

x2 + Ka*x - Ka*[HA]initial = 0

resulting in:

x = 0.5 * [ - Ka + SqRoot( Ka2 + 4*Ka*[HA]initial) ]

pH Levels

How do you lower the PH level in a swimming pool?

Your local pool store should have pH decreaser.

Answerby buying a chemical called pH minus AnswerHi Aaron,

You can use the pH Minus product mentioned or you can go purchase some Muriatic Acid. Be careful using this as it does have a very strong odor and is harmful if breathed or stays on your skin too long. I've used both pH Minus and muriatic acid. My experience with pH Minus (a dry acid) is that it worked just fine in lowering my pH level. I've have good luck, and quick results, in lowering my pH levels and Total Alkalinity levels, which has been a very big problem for me this season thus far.

You want to maintain your pH levels at about 7.6 - 7.4 .

You can use muriatic acid. Just be careful as it's, obviously, acidic and will eat through 5 layers of skin before you can wash it off. Goggles, and rubber gloves for safety.

Also, run your pH between 7.6-7.8, not 7.4. The pH in water will naturally rise and when you get your alkalinity in range, about 80-100ppm, your pH should be locked in at 7.6-7.8. You'll need to use too much acid to keep your pool pH lower. Most "pool experts" say to run your pH around 7.2, and that's just plain wrong.

They get their info. from an index used by your local water treatment system, and not from an index specifically designed for pools.

Dry acid is about 4 times more expensive than muriatic acid. Chlorine is about 80% efficient at a pH of 7.2 and only 40% efficient at 7.8 meaning it takes twice as much chlorine at the higher pH to provide equal sanitation. Keep the Total Alkalinity at a minimum of 100ppm even if you have to add a little baking soda once in awhile, especially if you are using any dry or tablet form of stabilized chlorine (isocyanurates).

pH Levels

What is pH of Triacetin?

The pH of Triacetin is about 5

pH Levels

What is a pH level?

pH is defined as

pH = pH = -log10[H+]

It is explicitly a measure of the concentration of hydrogen ions in an aqueous solution which also indicates how acid or basic the solution is. In any aqueous solution, the product of the concentrations of hydrogen and hydroxide ions is 10-14, i.e. [H+][OH-] = 10-14, when the values are given in moles per liter.

In a neutral solution the concentration of [H+] and [OH-] ions is balanced at 10-14, moles per liter of each (and the product [H+][OH-] = 10-14,). If you plug that back into the definition of pH you will see it gives a value of pH = 7 so neutral solutions have a pH of 7. Solutions with more hydrogen ions will be acidic and have a lower pH; solutions with more hydroxide ions will be basic and have a higher pH (because to maintain the product of hydrogen ions and hydroxide ions at 10-14, the concentration of hydrogen ions has to go down).

pH Levels

What is the optimum pH of amylase?

It depends on what amylase you're talking about. For example, the amylase found in saliva has an optimum pH of around 5.6 whereas amylase from the pancreas has an optimum pH around 7.

pH Levels

How do you increase the PH level in a swimming pool?

Usually, but not always, low Total Alkalinity (T/A) and low pH go hand in hand. Soda ash (sodium carbonate) will raise the pH without significantly affecting T/A and baking soda (sodium bicarbonate) will raise Total Alkalinity without significantly affecting the pH.

pH Levels

What is the pH of tequila?

The pH appears to be be around 5.2 as I have found in researching the answer...

Here is where I found my information.


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