Write two mass balances for a 1.0Lsolution containing 0.100molof sodium acetate.

Short Answer

Expert verified

The mass balances areNa+=0.100M and CH3CO2-+CH3CO2H=0.100M.

Step by step solution

01

Concept used.

Mass balance:

All species in a solution containing a certain atom (or group of atoms) must be equal to the amount of that atom (or group) given to the solution.

02

Step 2: Calculate the two mass balances.

By definition, mass balance of the solution is given by

For sodium ion:

Na+=0.100M

For acetate ion:

CH3CO2-+CH3CO2H=0.100Mdissociatedproductundissociatedproductamountofaceticacidputintothesolution

Therefore, mass balance equation for 1.0L solution of 0.100molNa+CH3CO2-was given.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Systematic treatment of equilibrium for ion pairing. Let’s derive the fraction of ion pairing for the salt in Box 8-1, which are 0.025FNaCI,Na2SO4,MgCI2,MgSO4. Each case is somewhat different. All of the solutions will be near neutral pH because hydrolysis reactions of Mg2+,SO2-4,Na+,CI-have small equilibrium constants. Therefore, we assume that H+=OH-and omit these species from the calculations. We work MgCI2as an example and then you asked to work each of the others. The ion-pair equilibrium constant, Kipcomes from Appendix J.

Pertinent reaction:

Mg2+CI-֏MgCI+aqKip=MgCI+aqγMgCI+Mg2+γMg2+CI-γCI-logKip=0.6.pKip=-0.6A

Charge balance (omitting H+,OH-whose concentrations are both small in comparison with Mg+,MgCI+,CI-:

role="math" localid="1655088043259" 2Mg2-+MgCI+=CI-B

Mass balance:

Mg2-+MgCI+=F=0.025MCCI-+MgCI+=2F=0.050MD

Only two of the three equations (B),(C) and (D) are independent. If you double (c) and subtract (D) , you will produce (B). we choose (C) and (D) as independent equations.

Equilibrium constant expression : Equation (A)

Count : 3 equations (A,C,D) and 3 unknowns Mg2+,MgCI+,CI-

Solve: We will use Solver to find

numberofunknowns-numberofequiliberia=3-1=2unknown concentrations.

The spreadsheet shows the work. Formal concentration F=0.0025Mappears in cell G2. We estimate pMg2+,pCI-in cell B8and B9. The ionic strength in cell B5is given by the formula in cell H24. Excel must be set to allow for circular definitions as described on page role="math" localid="1655088766279" 179. The sizes of role="math" localid="1655088853561" Mg2+,CI-are from Table 8-1and the size of MgCI+is a guess. Activity coefficient are computed in columns E,F. Mass balance b1=F-Mg2+-MGCI+,b2=2F-CI--MgCI+appears in cell H14,H15, and the sum of squares b21+b22 appears in cell H16. The charge balance is not used because it is not independentof the two mass balances.

Solver is invoked to minimizes b21+b22in cell H16be varying pMg2+,pCI-in cells B8and B9. From the optimized concentration, the ion-pair fraction =MgCI+F=0.0815is computed in cell D15.

The problem: Create a spreadsheet like the one for MgCI+to find the concentration, ionic strength, and ion pair fraction in 0.025MNaCI. The ion pair formation constant from Appendix J is log Kip=10-0.5for the reaction Na++CI-֏NaCIaq. The two mass balances are Na++NaCIaq=F,Na+=CI-Estimate pNa+,pCI- for input and then minimizes the sum of square of the two mass balances.

Write the charge and mass balances for dissolving CaF2 in water if the reactions are

role="math" localid="1654770961556" CaF2(s)ٟCa2++2FCa2++H2OٟCaOH++H+Ca2+FؚCaF+CaF2(s)ؚCaF2(aq)F+H+ؚHF(aq)HF(aq)+FؚHF2

14.The temperature-dependent form of the extended Debye-

Hückel equation 8-6 is

logγ=(-1.825×106)(εT)-3/2Z2μ1+αμ/(2.00εT)

where εis the (dimensionless) dielectric constant* of water, T is

temperature (K), Z is the charge of the ion,μis ionic strength (mol/L),andαis the ion size parameter (pm). The dependence of ´

on temperature is

role="math" localid="1654916203154" ε=79.755e(-4.6×10-3)(T-293.15)

Calculate the activity coefficient ofSO42-at50.00°Cwhenμ=0.100M. Compare your value with the one in Table 8-1.

FindγforCl- in 0.33mMCaCl2.

Write the charge balance for an aqueous solution of arsenic acid, H3AsO4, in which the acid can disassociate to role="math" localid="1654936423245" H3AsO-4,HAsO42-,andAsO43-. Look up the structure of arsenic acid in Appendix G and write the structure ofHAsO2-4

See all solutions

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free