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Shweta Thakur posted an Question

October 04, 2020 • 00:44 am

30 points

IIT JAM
Chemistry (CY)

Plz explain about ionization constant of water....

plz explain about ionization constant of water.cbnb...

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Dinesh khalmaniya 1

check it https://youtu.be/k6gpQy6H490
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Boddu rama krishna

all constants refered to: Kc, Kw, Ka, and Kb are temperature-dependent. All discussions are assumed to be at 25 °C, i.e. standard temperature. The following equation describes the reaction of water with itself (called autoprotolysis): H2O + H2O ⇌ H3O+ + OH¯ The equilibrium constant for this reaction is written as follows: [H3O+] [OH¯]Kc =––––––––––– [H2O] [H2O] However, in pure liquid water, [H2O] is itself a constant value. To demonstrate this, consider 1000 mL of water with a density of 1.00 g/mL. This 1.00 liter (1000 mL) would weigh 1000 grams. This mass divided by the molecular weight of water (18.0152 g/mol) gives 55.5 moles. The "molarity" of this water would then be 55.5 mol / 1.00 liter or 55.5 M. The solutions studied in introductory chemistry are so dilute that the "concentration" of water is unaffected. So 55.5 molar can be considered to be a constant if the solution is dilute enough. Cross-multiplying the above equation gives: Kc [H2O] [H2O] = [H3O+] [OH¯] Since the term Kc [H2O] [H2O] is a constant, let it be symbolized by Kw, giving: Kw = [H3O+] [OH¯] This constant, Kw, is called the water autoprotolysis constant or water autoionization constant. (Sometimes the prefix auto is dropped, as was done in the title of this section.) It can be determined by experiment and has the value 1.011 x 10¯14 at 25 °C. Generally, a value of 1.00 x 10¯14 is used. From the chemical equation just above, it can be seen that H3O+ and OH¯ concentrations are in the molar ratio of one-to-one. This means that [H3O+] = [OH¯]. Therefore the values of [H3O+] and [OH¯] can be determined by taking the square root of Kw. Hence, both [H3O+] and [OH¯] equal 1.00 x 10¯7 M in pure water. This leads to several important results in the acid base world.
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why concentration of h + and oh - is equal
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Priyanshu kumar Best Answer

https://youtu.be/asZDNdQB1cs check this
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and sir plz tell that why we exclude water from equilibrium constant
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we can't consider pure solid and pure liquid as its concentration remain constant
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we consider aqueous and gaseous part
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sir
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sir plz answer my next questions
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