Chem 26.1 Appendix ATQ 7

D. Gevaña/ Chemistry 26.1 (2017)

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APPENDI X St andar di zat i onofEDTASol ut i on

St andar dCaCO3  s ol ut i on Wei ghtofpureCaCO3:0. 50g For mul ama mas sof1  s t andar d:100. 09g/mol °

% Puri t yofpureCaCO3:99. 9% Vo l umeo ffina ls o l ut i o n:1 0 0 . 0mL mL Wor ki ngs t andar dCaCO3  s ol ut i on Vol umeofs t andar dCaCO3s ol ut i on:5. 0mL mL Vo l umeo ffina ls o l ut i o n:5 0 . 0mL mL Tr i al Vol umeofwor ki ngCa( I I )s t andar d,mL Ne tvol umeofEDTA,mL M EDTA Ave r ageM EDTA Ti t e r

1 10. 0 6. 8

2 10. 0 6. 7 -3

3 10. 0 6. 7 -3

-3

7.34 × 10 7 .45 .45 × 10 7 .45 .45 × 10 −3 0.007412007858 0.007412007858 M or 7.41 × 10  M 0.7418678665 0.741867866 5 mg/mL or 0.74 mg/mL mg/mL

Samp mpl eAn Anal ys i s Br andofmi ner alwat erus ed:Vi va!

mg  L mg 1 0  L

Mi ne r a lWa t e rc o nt e nt :5 4

ppm CaCO3  f r om ppm Ca ppm CaCO3  f r om ppm Mg Tot alwat e rhar dne s s : Tr i al Vol umeofwat e rs ampl e ,mL Ne tvol umeofEDTA,mL Tot alHar dnes s Aver age RSD ConfidenceI nt er val

Ca Mg

134. 86ppm 41. 18ppm 176. 04ppm 1 50. 0 7. 3

108.31 ppm

2 50. 0 7. 3

108.31 ppm 107.82 ppm 7. 93ppt

 107.  107. 82 ± 2.11 2.11

3 50 . 0 7 . 2

106.83 ppm

D. Gevaña/ Chemistry 26.1 (2017)

Ca l c ul a t i ons

1 molCaCO 3

 × %purity = 100.09 gCaCO 3  L solution 1 molCaCO 3 99.9 0.50 gCaCO 3  ×  ×   =0 . 0 4 9 9 0 5 08 5 4 2M 100.09 gCaCO 3 100 0.100  L

Ms t oc k CaC O3

=

gCaCO 3  ×

M wor ki ngs t andar d CaC O3

¿

 M stock × V  stock  V w.std.

=

(0.04990508542 M ) ( 5 mL ) = 0.004990508542 M  50 mL

St andar di zat i onofEDTASol ut i on

M EDTA

 M w.std.soln × V w.std.soln. × ¿

1 mol EDTA 1 mol CaC O3

V  EDTA

Tr i al1

  0.004990508542 M × 10 mL × M E!" #

1 mol EDTA 1 mol CaC O3

6.8 mL -3

# 0.00733898315 M or 7.34 × 10  M Tr i al2

  0.004990508542  M × 10 mL × M E!" #

1 mol EDTA 1 mol CaC O 3

6.7 mL -3 # 0.007448520212 M or 7 .45 × 10  M

Tr i al3

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D. Gevaña/ Chemistry 26.1 (2017)

  0.004990508542  M × 10 mL × M E!" #

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1 mol EDTA 1 mol CaC O 3

6.7 mL -3

# 0.007448520212 M or 7 .45 × 10  M Ave r a geM EDTA

 M  EDTA ave #

0.00733898315 M $ 0.007448520212 M $0.007448520212 M 3

# 0.007412007858 M or 7.41 × 10

−3

 M

1 mmolCa CO3

!itr # M  EDTA ave  × E& o'  * 3 ×

1 mmol EDTA 1 mmo+  *3 mg # (   0.007412007858 M ) 100.09 × mmol 1 mmo+ E!" # 0.7418678665 mg/mL or 0.74 mg/mL

(

)

Sampl eAnal ys i s

(

)(

)(

)(

)(

1 mo+  *3 100.09g 1 mo+   40.078 g 1 mo+  1 mo+  *3 # 134.8585259 ppm or 134.86 ppm  * 3

ppm * 3  'rom ppm  # (54 ppm )

(

)

1 mo+ ()(* 3 100.09g 1 mo+  Mg 24.305 g 1 mo+ Mg 1 mo+ ()(* 3 # 41.18082699 ppm or 41.18 ppm * 3

ppm ()(* 3 'rom ppm Mg # ( 10 ppm )

)

!ot+ &tr ,r (torti+) # 134.8585259$ 41.18082699 # 176.0393529 ppm or 176.04 ppm  !ot+ ,r #

!itr × t o+um o' E!" o+um o' &tr mp+

Tr i al1

!ot+ ,r #

(0.7418678665 mg/mL) (7.3 mL) # 108.3127085 ppm or 108.31 ppm 0.050 L

  Tr i al2

!ot+ ,r #

(0.7418678665 mg/mL) (7.3 mL) # 108.3127085 ppm or 108.31 ppm 0.050 L

Tr i al3

!ot+ ,r #

(0.7418678665 mg/mL) (7.2 mL)  # 106.8289728 ppm or 106.83 ppm 0.050 L

D. Gevaña/ Chemistry 26.1 (2017)

"rg !ot+ ,r #

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108.3127085 $ 108.3127085 $ 106.8289728 #107.8181299 ppm or 107.82 pp 3

−107.82 ¿2 ¿ ¿ 3 −1 2 108.31 −107.82 ¿ +¿ 2 108.31 −107.82 ¿ +¿ ¿ ¿ √ ¿ 106.83

Stanar Deviati!n" s #

'eative Stanar Deviati!n #

C*#

 x´ ±

ts

√ n

 #



´ 

107.8181299

2.121333333 # 107. $2 +nterva, 105.71 −109.93

± 2.11

#

±

.$%447$3&$4

0.8544783984 × 1000  ppt   # 7.&2%1$2$&1 t 107.8181299

( 4.30 )( 0.8544783984 ) √ 3

 #

107.8181299 ±