InterviewSolution
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InterviewSolution
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Which of the following mixture solution has `pH ~~ 1.0`?A. `100 mL M//10 HCI + 100 mL M//10 NaOH`B. `55 mL M//10 HCI +45 mL M//10 NaOH`C. `10 mL M//10 HCI + 90 mL M//10 NaOH`D. `75 mL M//5 HCI +25 mL M//5 NaOH` |
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Answer» Correct Answer - D a. `HCI = 100 xx (1)/(10) = 10 mEq` `NaOH = 100 xx (1)/(10 = 10 mEq` Salt of `S_(A)//S_(B)` is formed, `pH = 7` b. `HCI = 55 xx (1)/(10) = 5.5 mEq` `NaOH = 45 xx (1)/(10) = 4.5 mEq` `1.0 mEq` of `HCI` is left. So `pH` will be in acidic range but not equal to one, since concentration fo `HCI` is very low. c. `HCI =10 xx (1)/(10) = 1mEq` `NaOH = 90 xx (1)/(10) =9 mEq` `8 mEq of NaOH` is left and `pH gt 7`. d. `HCI = 75 xx (1)/(5) = 15 mEq` `NaOH = 25 xx (1)/(5) = 5 mEq` `15 - 5 = 10 mEq of HCI` is left. `:. [HCI] = [H_(3)O^(o+)] = (10 mEq)/((75+25)mL) = (10)/(100) = 0.1M` `pH =- log (10^(-1)) = 1`. |
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