0
Here is the first step to convincing you that the pKa of water should not be 7: water is clearly a weaker acid than hydrogen sulfide, whose pKa is 7.04, or boric acid, 9.14, or hydrogen cyanide, 9.31 The real problem is why the pKa should not be 14.0 -- the same as pKw Here is the reason: Kw is defined as [H+]*[OH-], and this turns out to be 1.E-14. For any acid HA in water, though, Ka is defined as [H+]*[A-]/[HA] So if we think of water as an acid, Ka = [H+] * [OH-] / [H2O] = 1.0E-14 / [H2O] What do we do for [H2O]? Well, 1 g of water occupies 1 mL, near enough, which means that 18 gram of water = 1 mol of water occupies 18 mL. So we can fit 55.6 mol of pure water in 1.00 L. It is therefore fair to say that the "concentration" of water is 55.6 M, and so Ka = 1.8E-16 The log of 1.8E-16 to base 10 is -15.75, which is the pKa value quoted in your question.
What else can I help you with?
How many more hydroxide ions are there in a solution with a pH of 9 than in a solution with a pH of 3?
The concentration of hydroxide ion is realted to pH by the pKw (10-14) At pH 9 the concentration of OH- is 10-5, at pH 3, 10-11. The ratio is 106 so there are a million times as many OH- in pH 9.
What kind of water is there?
Tap water Drinking water Sewer water Pipe water River Water Mineral water Pure water Dirty water
Why does water float and sink in water?
Water floats and sinks in water because water in water results in the mixing and diffusion of the water in the other water. This may sound silly, but the question was one dealing with water in water. The mixture of water and water will, after a time, become one homogenous volume of liquid.
DOES THE WATER CYCLE CLEAN THE WATER?
Yes, water cycle cleans the water. Rain water is purest form of water.
What form of water is the most abundant at any time in the water cycle?
water vapor
What is the pH if pKw is 14.26?
I will assume you are asking about the pH of pure water if pKw is 14.26. The relationship between pH, pOH, and pKw is as follows: pH + pOH = pKw. If it is pure, neutral water (no acids or bases present), then pH = pOH, so: pH + pOH = 14.26 2(pH) = 14.26 pH = pOH = 7.13
What is the value of pKw?
pKa+pKb=pKw=14
Where is Sam's Club on cobb pkw in marietta ga?
there is not
How do you say red car in German?
red car = rotes Auto red car = roter Wagen red car = roter PKW
Where is the On The Chisholm Trail Association in Duncan Oklahoma located?
The address of the On The Chisholm Trail Association is: 1000 Chisholm Trail Pkw, Duncan, OK 73533-1539
Where can I find an industrial mixing equipment?
http://www.alfalaval.com/campaigns/tankequipment/mixing-and-agitation/product-overview/pages/product-overview.aspx?pkw=industrial%20mixing%20equipment is a website that you can find an industrial mixing equipment.
Why is water known as an acid as well as base?
Because water molecules can both split off and accept a proton H+ :H2O + H+ ---> H3O+ (hydroxonium ion)H2O ---> H+ + OH- (hydroxide ion)This is called the 'Water equilibrium of internal protolysis: 2H2O OH- + H3O+ pKw = 14 or Kw = [H3O+]*[OH-] = 10^(-14)
Is it true that the sum of pka and pkb is always equal to 14 at all temperature for any acid?
In general, at 25°C the sum of pKa and pKb for a conjugate acid-base pair will equal 14 due to the auto-ionization of water. However, at different temperatures, the sum may vary slightly due to changes in the equilibrium constant of water ionization.
Which of the following describes how the pH of the solution could change?
There factors include: -Ionic strength The number of ions and charges present affect the ion activity coefficient and hence the activity of charges species in the solution -Dilution of buffer with water The pH will change and this will affect the ion activity coefficient. The activity of charges species in the solution is hence affected since water itself can act as an acid or base. -Temperature The effect of temperature on weak acids and its conjugate base as a buffer is small due to small changes in its ionization constant Ka as a function of the temperature. As for a weak base and its conjugate acid, the pH is constant only if the temperature is constant. If the temperature fluctuates, the pH changes according to the changes in pKw for water and pKw is very susceptible to temperature changes.
How many more hydroxide ions are there in a solution with a pH of 9 than in a solution with a pH of 3?
The concentration of hydroxide ion is realted to pH by the pKw (10-14) At pH 9 the concentration of OH- is 10-5, at pH 3, 10-11. The ratio is 106 so there are a million times as many OH- in pH 9.
How many times more hydroxide ions are there in a solution with a pH than in a solution with a pH of 3?
The concentration of hydroxide ion is realted to pH by the pKw (10-14) At pH 9 the concentration of OH- is 10-5, at pH 3, 10-11. The ratio is 106 so there are a million times as many OH- in pH 9.
How many times more hydroxide ions are in a solution with a pH of 9 than in a solution with a pH of 3?
The concentration of hydroxide ion is realted to pH by the pKw (10-14) At pH 9 the concentration of OH- is 10-5, at pH 3, 10-11. The ratio is 106 so there are a million times as many OH- in pH 9.
