## anonymous one year ago Pure water is neutral. What is the appropriate justification for this?

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1. Teddyiswatshecallsme

Choice A, neutral means the H+ ions equal the OH- ions, giving a pH of 7. The first choice is pretty much that exact definition

2. anonymous

@Teddyiswhatshecallsme where is choice A from?

3. anonymous

Yes, pure water is neutral because we have an equal concentration of $H _{3}O ^{+}$ and $OH ^{-}$ ions. In fact water only very slightly ionizes, so $K _{w}$ value is very very small$= - 1 \times10^{-14}$ Finding the equilibrium expression of water gives us $Kw = [OH ^{-}][H3O ^{+}]$ That is for the reaction: $H _{2}O + H _{2} O \leftarrow \rightarrow H _{3}O ^{+} + OH ^{-}$ And $Kw = 1 \times 10 ^{-14}$ And $[OH ^{-}] = [H _{3} O ^{+}]$ $= 1 \times 10^{-7}$ Finding pH= $-\log ([H _{3} O ^{+}] )$= $-\log( 1 \times 10^{-7}) = 7$ 7 pH is neutral.

4. Teddyiswatshecallsme

Just A. lolol

5. Teddyiswatshecallsme

Multiple choice.