InterviewSolution
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InterviewSolution
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An acid solution of `pH=6` is diluted `1000` times, the `pH` of the final solution isA. `6.99`B. `6.0`C. `3.0`D. `9.0` |
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Answer» Correct Answer - A `pH= 6 means [H^(+)]=10^(-6) M`. After dilution, the hydrogen ion concentration becomes `10^(-9) M`. Under such conditions, the hydrogen ions obtained from water cannot be neglected. ` :.` Total `[H^(+)]=10^(-9)+10^(-7)` (approx). ` =10^(-7)(10^(-2)+1)=10^(-7) (1.01)` [The contribution of `H^(+)` from water will not be exactly `10^(-7)` but still we can make an approximation in an objective problem and take it as `10^(-7)`] `pH= -log[H^(+)]= -1.01xx10^(-7)=7-0.0043=6.9957` |
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