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56.0 g KOH, 138.0 g K_(2)CO_(3) and 100.0 g KHCO_(3) is dissolved in water and the solution is made 1 L. 10 " mL of " this stock solution is titrated with 2.0 M HCl. Which of the following statements is/are correct? |
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Answer» When phenolphthalein is used as an indicator from the very beginning the titre value of HCl will be 60 mL `m" Eq of "(KHCO_(3))/(L)=(100)/((100)/(1))xx10^(3)=1000=(20)/(20)mL` (b). With phenolphthalein: `m" Eq of "KOH+(1)/(2)m" Eq of "K_(2)CO_(3)=m" Eq of "HCl` `20+(40)/(2)=vxx1N(n=1)` `V_(HCl)=40mL` (c). With methyl orange: `m" Eq of "KOH+m" Eq of "K_(2)CO_(3)+m" Eq of "KHCO_(3)=m" Eq of "HCl` LTBRGT `20+40+20=Vxx1N` `V_(HCl)=80mL` (d). With methyl orange after the first end point: `(1)/(2)m" Eq of "K_(2)CO_(3)+m" Eq of "KHCO_(3)=m" Eq of "HCl` `20+20=Vxx1N` `V_(HCl)=40mL` |
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