A) 8
B) -8
C) Between 7 and 8
D) Between 6 and 7
Correct Answer: D
Solution :
Between 6 and 7 \[\operatorname{From} acid, \left[ {{H}^{+}} \right]{{10}^{-8}}M\] \[\operatorname{From} \left[ {{H}^{+}} \right]{{10}^{-7}}M\] \[\therefore \,\operatorname{Total} \left[ {{H}^{+}} \right]={{10}^{-8}}+{{10}^{-7}}\] \[={{10}^{-8}}\left( 1+10 \right)\] \[=11\times {{10}^{-8}}\operatorname{M}\] \[\therefore \operatorname{pH}=-\log \left[ {{H}^{+}} \right]\] \[=-\log \left( 11\times {{10}^{-8}} \right)\] \[=-\left[ \log 11+\log {{10}^{-8}} \right]\] \[=-\left[ 1.0414-8 \right]\] From [irJlO-'M \[=6.9586=6.96\]You need to login to perform this action.
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