Data Concentration of HCl titrant (M) 529 M Test Solution Preparation of Borax S
ID: 1064088 • Letter: D
Question
Data Concentration of HCl titrant (M) 529 M Test Solution Preparation of Borax Solution I. Volume of sample (mL 5.De OS 5.01 3, 5.03 S. 9 2. Temperature of sample (oC) 33 C 1.9e c 3 C 12 C 5or Analysis of Borax Test Solutions l. Buret reading, final (mL) 22 mL. LIC 24. smu 34. 38.5mb 3001L 2. Buret reading, initial (mL) Hqmt 50mL 22 m L 45 L. Hom/ 50 mL 3. Volume of HC1 added (mL) 2 mL mu 12SmL lo smb esinL 20m Calculations Data Analysis 1. Temperature (K) 2.1/T (K I) 3, mol HCI used. 5. [B405(OH) (M 6. Solubility of borax (M) 7. Solubility product, 8. in Ksp Thermodynamic Results AG (k J), at 298 K rev2013 18-6Explanation / Answer
Data analysis:
1
2
3
4
5
6
Temperature (K)
306
289
274.9
292.3
315
323
1/T (K-1)
0.00327
0.00346
0.00364
0.00342
0.00317
0.00309
Mol HCl used (mol)
0.0041283** (see sample calculation below)
0.001529
0.00191125
0.00164505
0.00099385
0.003058
Mol B4O5(OH)42-
0.00206415** (see sample calculation)
0.0007645
0.000955625
0.0008225
0.000496925
0.001529
[B4O5(OH)42-] (M)
0.408** (see sample calculation)
0.151
0.188
0.160
0.099
0.300
Solubility of borax (M)
0.408** (see sample calculation below)
0.151
0.188
0.160
0.099
0.300
Solubility product, Ksp
0.2717
0.0138
0.0266
0.0164
0.0039
0.1080
ln Ksp
-1.303
-4.283
-3.627
-4.110
-5.547
-2.226
Mol HCl used = (volume of HCl used in L)*(concentration of HCl in mol/L) = (49 – 22)mL*(1 L/1000 mL)*(0.1529 mol/L) = 0.0041283 mol.
Mol B4O5(OH)42-:
Write down the balanced chemical equation
B4O5(OH)42- + 2 H+ + 3 H2O -----> 4 B(OH)3
Moles B4O5(OH)42- = 2*moles H+ (as per the stoichiometric equation).
Moles B4O5(OH)42- = (0.0041283 mol H+)*[1 mol B4O5(OH)42-/2 mol H+] = 0.00206415 mol.
[B4O5(OH)42-] = [moles of B4O5(OH)42-]/[(5.06 mL)*(1 L/1000 mL)] = (0.00206415 mol)*(1000)/(5.06 L) = 0.4079 mol/L 0.408 mol/L
Solubility of borax:
Write down the dissociation of borax as
Na2B4O7.10H2O (s) <====> 2 Na+ (aq) + B4O5(OH)42- (aq) + 8 H2O (l) ….(a)
Solubility of borax = concentration of B4O5(OH)42- in M = 0.408 M
Solubility product:
Look at equation (a) above.
[Na+] =2*[B4O5(OH)42-] (As per the stoichiometric equation, the molar ratio of Na+ and B4O5(OH)42- is 2:1)
===> [Na+] = 2*(0.408 M) = 0.816 M
Ksp = [Na+]2[B4O5(OH)42-] = (0.816)2(0.408) = 0.2717 0.272
1
2
3
4
5
6
Temperature (K)
306
289
274.9
292.3
315
323
1/T (K-1)
0.00327
0.00346
0.00364
0.00342
0.00317
0.00309
Mol HCl used (mol)
0.0041283** (see sample calculation below)
0.001529
0.00191125
0.00164505
0.00099385
0.003058
Mol B4O5(OH)42-
0.00206415** (see sample calculation)
0.0007645
0.000955625
0.0008225
0.000496925
0.001529
[B4O5(OH)42-] (M)
0.408** (see sample calculation)
0.151
0.188
0.160
0.099
0.300
Solubility of borax (M)
0.408** (see sample calculation below)
0.151
0.188
0.160
0.099
0.300
Solubility product, Ksp
0.2717
0.0138
0.0266
0.0164
0.0039
0.1080
ln Ksp
-1.303
-4.283
-3.627
-4.110
-5.547
-2.226
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.