module 2
In Moduale If ( Hi-2, H-3, 1 -4), soloct appropriate and insppropriate juatificason statentents provided in the Discursiaian Soction, based an a partiaf lab roport. Module II -2 - Resuhts: The pH detertined by plf electrode is 11 dit tar 6.0010M NaOit and 10.t21 for. 0.0010MNH,N1O tolutions. - Justfications in Disbustion (Croose ONE of the folowivg pornthe juaticition smomontr) (a) NaOHNa++OH; NaOH is a Arong base with 100 ' dssocinton to the' and Or: Therefore {OH]=0.0010M,pCH= slogo. 0010=3.00 (b) For NaOH solution, pH =14pOH=143.00=11.00, which is dose so tre detwined value of 1102 . (c) One should always wear ploves when handing NaCH because it is a seong base (d) The reaction of NaOH with HCl releases heat. (e) NH2+H2ONH4++OH2NH2H4O is a weak base that pertally reacts wat keO rolense OH; Therelore, the NH, HJO soluton eontsins less OHr thon that in NaOH solution at the same concentration. (i) NH3H2O reacts with HCl to form salt NH2HO+HCl=NH/Cl+HLO - Conclusions A 100 s dissociation of the strong bose NaCH leads to more Oht released. thus a higher pH than that of the woak bape NHyHO at the same concentration. Module II 3 - Oojective To axplain why HCI is a stronger acid than CHCOOH - Results The pH determined by pH electrode is 4.00 for 0.00010MHCi and 4.54 for 0. M CH,COOH solutions - Justfications in Discussion (Choose ONE of the following possible justification statem (a) Both HCl and CH3COOH react with NaOH to form salts. NaCl is a strong CH.COONa is a weak salt. (b) A lower pH was found in the HCl solution (pH=4.00) but not in the CHiCOOh (pH=4.54) of same concentration (0.00010M). Hodule II (ili-2, It-3, fl-4), select appropriate and inappropriate justification ceminents provided in the Discussion Section, based on a partial fab report. Module Il - 2 - Cejective. To explain the differenoe in basicily betesen NaDH and NHH H3O sclutions - Resuls: The pH determined by pit elecrode is 11.02 for 0.0010MNaOH and 10.12for. 00050MNH NtuO solutions - Justhications in Discussion (Choose QNE of the following possible jusbilicatorn stalementa): (a) NaOHNa7+OH2; NaOHt is a strong base with 100% dissocieton to Na and OH. Therefore, [CH]=0.0010M,pOH=log,0010=300 (b) For NaOH solution, pH=14pOH=14300=11.00, which is dose to the destarmined value of it in. (c) One should always wear glowes when handing NaCH becsuse it is a strong base (a) The reaction of NaOH win HiCl relesses heat (e) NH2+H6O+NH4+Oit2, NH,H,HO is a weak base that partaly reacts with HOO to release OH, Therelore, the NH2HOO soluson contains wss. OH than that in NaO.t solution at the ssme concentation. - Condusions A 100% dissocition of the stoog bese NuCH leads ta more Ort released. thus a higher git than Frat of the weak base NHGHFO at the sarte concentration Module II - 3 - Objective. To explain why HCl is a strenger add than CH COOH - Result: The ph detemined by pH electrode is 4.00 for 0.00010MHC and 4.54 for 0.00010 M CHbOOOH solutions. - Uusafications in Discussion (Choose ONE of the followerg possible gustifcution atabementa). (a) Both HCl and CHCOOH react with NaOH to form sats. NaCl is a stong sait but CH COOWa is a weak sye. (b) A lower pH was found in the HCl soluton (oH =4.00) but not in the CHLCOOH soltion (pH=4.54) of same concentration (0.00010M) In Module II (II-2, II-3, II-4), select appropriate and inappropriate justification statements provided in the Discussion Section, based on a partial lab report. Module II - 2 - Objective: To explain the difference in basicity between NaOH and NH3H2O solutions - Results: The pH determined by pH electrode is 11.02 for 0.0010MNaOH and 10.12 for 0.0010MNH3H2O solutions. - Justifications in Discussion (Choose ONE of the following possible justification statements): (a) NaOHNa++OH,NaOH is a strong base with 100% dissociation to Na+and OH. Therefore, [OH]=0.0010 M,pOH=log0.0010=3.00 (b) For NaOH solution, pH=14pOH=143.00=11.00, which is close to the determined value of 11.02. (c) One should always wear gloves when handling NaOH because it is a strong base. (d) The reaction of NaOH with HCl releases heat. (c) NH3+H2ONH4++OH,NH3H2O is a weak base that partially reacts with H2O to release OH. Therefore, the NH3H2O solution contains less OHthan that in NaOH solution at the same concentration. (1) NH3H2O reacts with HCl to form salt: NH3H2O+HCl= NH4Cl+H2O. - Conclusions: A 100% dissociation of the strong base NaOH leads to more OHreleased, thus a higher pH than that of the weak base NH3H2O at the same concentration
