Question
Asked Mar 7, 2020
65 views

A sample of 0.1687 g of an unknown monoprotic acid was
dissolved in 25.0 mL of water and titrated with 0.1150 M
NaOH. The acid required 15.5 mL of base to reach the
equivalence point. (a) What is the molar mass of the acid?
(b) After 7.25 mL of base had been added in the titration,
the pH was found to be 2.85. What is the Ka for the unknown
acid?

check_circle

Expert Answer

Step 1

Sub-part (a):

Calculate the number of moles of NaOH:

1 mL = 0.001 L

Chemistry homework question answer, step 1, image 1

 

Step 2

Since a monoprotic is taken, equal number of moles of the acid and NaOH are titrated to reach the equivalence point. So, number of moles of add is same as that of NaOH.

Calculate molar mass of unknown monoprotic acid:

Chemistry homework question answer, step 2, image 1

Hence, molar mass of unknown monoprotic acid is 94.78 g/mol.

Step 3

Sub-part (b):

Reaction between NaOH and monoprotic acid (HA) is,

Chemistry homework question answer, step 3, image 1

Calculate the number of moles of NaOH

Chemistry homework question answer, step 3, image 2

...

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.

Related Chemistry Q&A

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

Q: Stuck on this chem problem. You can select any that apply. Thank you.

A: The given molecule A and D are formed hydrogen bonding with themselves because these molecules have ...

question_answer

Q: Suppose 3.16g of barium nitrate is dissolved in 350.mL of a 31.0mM aqueous solution of sodium chroma...

A: Given: 3.16 g of barium nitrate is dissolved in 350.0 mL of a 31.0 mM aqueous solution of sodium chr...

question_answer

Q: A student was given a clear, colorless unknown solution in lab and told that the identity was either...

A: Given that following test are performed on an unknown solution. From the tests performed, we can ob...

question_answer

Q: find the empirical formula for the tin oxide formed? calculate the sn% and o%? calculate the %error ...

A: Given information: mass of crucible= 25.7700 g mass of crucible and tin =26.6952 g mass of crucible...

question_answer

Q: Experiment on equilibrium constant question 3

A: Let C, k, and Kc be the calculated concentration, used beer’s law constant, and calculated equilibri...

question_answer

Q: Suppose that, in the absence of a catalyst, a certain biochemicalreaction occurs x times per second ...

A: The Arrhenius equation is given below.

question_answer

Q: The deviation from ideal behavior of a gas is most evident at high temperature. Explain

A: Given statement: The deviation from ideal behavior of a gas is most evident at high temperature.  

question_answer

Q: A chemist at a pharmaceutical company is measuring equilibriumconstants for reactions in which drug ...

A: Given, Concentration of protein = 1.50 × 10-6 M Initial concentration of drug A = 2.00 × 10-6 M Init...

question_answer

Q: What is the mass of the solid NH4Cl formed when 77.0 g of NH3 is mixed with an equal mass of HCl? Wh...

A: Calculate the number of moles of ammonia and hydrogen chloride gas. The molar mass of ammonia is 17 ...