Question

Name Section QUESTIONS: EXPERIMENT 17 Date 1 In a hardness of water determination like the one performed in this experiment, it was found that a 25.00-ml sample of water required 12.25 mL of 0.0128 M EDTA solution for complete titration. What is the concentration (molarity) of Ca2+ ions in the water sample? What is the concentration of Caco (in mg/L) in the water sample? Describe the hardness level of the wate using the U.S. government standards, Ca?molarity CaCO3 concentration, mg/L_ hardness level 167

Answer 1

Dutevminatin Hardns f water Deteinah'mf cacentratimf ca ions in the atew Sample CMasily a. AnsNor- Formula MIVE MaV2 MIMdarily cat ious in the twater Sample Volume Sample wwater taken in the conical flask MMdaril disodium EDTA Sdwtion Volume disodium EDTA Consumed Mi ? M2 0.0128 = 3Sm V2= 18. as m MI M22 VI = 0.01a8 xl8 a5 a5 0.006272 M Molaril cat tons in the water 8ample is found to be The 0.006272 M

b. Estimation Cacos concentration Cin mg) i oater Sample Answer mde disodium EDTA mde Cacos Euivalent fautor lo00 mIM dis8odium EDTA 1xa0+1xi2) +36)aos IM disodium EDTA Caco3 1000m IM disodium EDTA = 0.1qmf Caco3 Ind I oM disedium EDTA O.0l amcalo 3 -1hew, 1a.25M0.0128 M disodium EDTA 11 = 12.as x 0.0188 x0.01 8 Cacos o.1 Caco 3 o.01568 11 The cancentratianf caco Present 25 Sample oter 0.01568 locond (1Lt) Samplesda? 1o0om x0.01568 5 0.6272 cacos = 62+.a MCacos Cacos concentrahinw (in mg/L) adw Sanmple 6a7.2aes

Hardnus level water o to 60 mg L 61 to 120 mgL 12l to 180gl Saft iwatr al calium Carbonate Hard atw as calium carbinala veay hardwate as calcum canb onale cacos Cmcentraton in malLd wates sample was found to be 627. 2 ma Hence, Ihe hardness level water is Very hard al per US Govt guide linet