Question
Asked Oct 22, 2019
71 views

A 25.0ml sample of a 0.3000 M solution of aqueous trimethylamine is titrated with a 0.3750 M solution of HCl. Calculate the pH of the solution after 10.0, 20.0, and 30.0 mL of acid have been added; pKb of (CH3)3N = 4.19 at 25oC.

1. pH after 10.0mL of acid have been added

2. pH after 20.0mL of acid have been added

3. pH after 30.0mL of acid have been added

check_circle

Expert Answer

Step 1

pH on adding 10.0mL HCl is calculated as follows,

help_outline

Image Transcriptionclose

Initialmoles N= /3 Concentration of CH Total volume 0.300M 25mL (25+10)mL 0.21M 0.3750M 10 mL (25+10)mL Concentration of HCl=Initialmoles Total volume - 0.107M (сн), (CH) NH HCl Cl + /3 Initial 0.21M 0.107M 0 0 Change Equilibrium 0.21M-x -X -X X х 0.107M-x 0.107M 0.107M Since, HCl is limiting reagent, x0.107M (CH) NH CHN ВН = pKb +log РОН-рКъ +log BJ 0.107M 4.19 0.0165 4.2 4.19log 0.103 pH 14-pOH 14-4.2 рH -9.8

fullscreen
Step 2

pH on adding 20.0mL HCl is c...

help_outline

Image Transcriptionclose

Initial moles N- Total volme Concentration of CH1 0.300Mx25mL 0.167M (25+20 mL Initia moles 03750M 20mL Total volume - 0.167M Concentrationof HC1 (25+20 mL (сн - HCl CH NH CI Initial Change Equilibrium 0.16 7M- 0.167M 0.167M 0 1 0.167Mx 0.167M 0.167M NH pH will be due to CH, NH H,O CH3 Cн. N + Initial 0.167M 0 0 Change Equilibrium 0.16 7M- pk pli-pk -14-4.19-9.81 K-10-981-155x10-10 N Kg (CH NH assumingx'tobevery sm all 155x10-10, 0.167Mx 2-155x10-10 0.167M)-0.25885 x10-10 x-v0.25 885x10-10-0.509x10-5 pHo,0]-log (0.50910-5 -5.29 pH-5.29

fullscreen

Want to see the full answer?

See Solution

Check out a sample Q&A here.

Want to see this answer and more?

Solutions are written by subject experts who are available 24/7. Questions are typically answered within 1 hour.*

See Solution
*Response times may vary by subject and question.
Tagged in

Science

Chemistry

General Chemistry

Related Chemistry Q&A

Find answers to questions asked by student like you
Show more Q&A
add
question_answer

Q: The speed of sound is 330 m/s. If fireworks are 1.5 km away, what is the length of the time delay be...

A: Given,speed of sound is 330 m/s.Distance between viewer and fireworks is 1.5km

question_answer

Q: Complete the table below, which lists information about seme diatomic molecules or molecular ions. I...

A: Given molecule:a.F2-b.O2c.Be2

question_answer

Q: Ok so I need help finding the net ionic equation for this reaction 3(NH4)2CO3 + AlBr3 = 6(NH4)Br(aq)...

A: The net ionic equation for the given reaction is to be written-3(NH4)2CO3 + AlBr3 = 6(NH4)Br (aq) + ...

question_answer

Q: If a sample of O2 gas has a pressure at 15.00 °C of 112,000 Pa, what is its pressure a.In units of a...

A: Given that the pressure of oxygen gas at 150C is 112,000 Pa.(a) 1 atm = 101325 Pa1 Pa = 1 / 101325 =...

question_answer

Q: The energy of a photon emitted when an electron underwent a transition to n = 3 energy level was 1.8...

A: The energy of a photon, which under went transition, can be calculated as,

question_answer

Q: Suppose 7.60 g  of CH4 is allowed to burn in the presence of 16.90 g  of oxygen.  CH4(g)+2O2(g)→CO2(...

A: The required balanced equation is given below.

question_answer

Q: Using the standard enthalpies of formation, what is the standard enthalpy of reaction?   CO(g)+H2O(g...

A: Enthalpy change of a reaction is calculated by subtracting the sum of enthalpies of formation of rea...

question_answer

Q: Arrange the following elements from greatest to least tendency to accept an electron Rank from great...

A: Chlorine is a chemical element with atomic number 17. Its electronic configuration is 1s2 2s2 2p6 3s...

question_answer

Q: Balance the chemical equation below using the smallest possible whole number stoichiometric coeffici...

A: A balanced chemical equation or reaction is the one in which the total number of atoms for each elem...