Question

In order to determine the hardness of α solution, a small amount of Eriochrome 2. Black T is added to 100 ml of sample. After addition of I1.2 ml of D.01 M EDTA solution, the color of the solution changes from red to blue. What is the hardness concentration in moles/liter and mg/liter cas CaCO,? Show that [HgOH'] is negligible in Example 5-2 3. 4. A water, pH 5.5, is dosed with 80 mg/liter of alum,C.co,-1x10-4. (a) How much hydrated lime, Cal(OH), is neoded so that the pH does not change during coagulation? (b) How much hydrated lime must be added to produce a water with a pH of 7.5 after coagulation? The calculation in Section 5-6 showed that the only complexes of significance in a typical natural water are the sulfato calcium and magnosium complexes Given a C.ca 1 x 10-3 M, CT.Ma n, 5 10-4 M and α very high sulfate concentration, CT,s04 z-2 x10-3 M, how much of the Ca and Mg is complexed with sulfate? 5. Given the conditions listed for development of Fig. 5.6, and a pH of 8.5, what 6. is the fraction of CTNi in the form of Ni(CN)- Given the conditions listed for development of Fig. 5.6, and a pH of 8.5, what is the fraction of CTI in the form of Ni(CN)? A solution contains 2 x 10-3 moles Ca2+/liter αnd 3 x 10-4 moles Mg2+/liter Given the formation constants for CaEDTA and MgEDTA of 1010.0 and 109.7, respectively, calculate (1) The concentration of MgEDTA2 αfter the addition of 1.5 x 10-3 moles EDTA liter of sample. (b) The concentration of MgEDTA after the addition of 2 x 10-3 moles EDTA /liter of sample. Does the presence of Mg?+ significantls interfere with the determinction o Cat by the EDTA titration procedure? What is the pH of α 10-5 M Cu(C104)2 solution? Check your answer to b certain that Cu(OH)s will not precipitate. Calaulato tha Ph.(OH) concentration at pH 6 for the conditions given i

Answer 1

As per guidelines, answer for a .2 given heve ToLal hardness of wate (n terw of Ca Cu3) 8x Volume o GDTA E DTA o Tume o water sample ny IL wr L HaydnesSof water sampleュ'12 by Mol aríng x Volume °1 E DTA Amou n o.Il 2 mmイ 2t 012 Amount of CalUz in İL