The pH of a solution is 10. What is its #[H^+]# concentration?

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Answer 1 · 2017-08-15T06:41:28

#[H^+]"/"[H_3O^+]=10^(-10)*mol*L^-1#

By definition, #pH=-log_10[H^+]#.

In water, under standard conditions, #pH# characterizes the autoprotolysis reaction.......

#2H_2OrightleftharpoonsH_3O^+ + HO^-#

#K_w=[HO^-][H_3O^+]=10^-14#, we take #log_10# of BOTH SIDES...

#log_10K_w=log_10[HO^-]+log_10[H_3O^+]#

And on rearrangement,

#underbrace(-log_10(10^-14))_(pK_w)=underbrace(-log_10[HO^-])_(pOH)underbrace(-log_10[H_3O^+])_(pH)#

And thus #14=pOH+pH#.