Why are you using phenolphthalein as an indicator

Assignment Help Chemistry

Reference no: EM131924340

Lab - The Titration of Vinegar

PRE-LAB QUESTIONS

1. Why are you using phenolphthalein as an indicator?

2. Estimate the volume reading for the burette depicted in Figure 10.1.

3. Distinguish between the endpoint and equivalence point.

4. If 12.66 mL of 0.250 M NaOH solution is used in a titration how many moles of OH^- were added? How many moles of H⁺ could be neutralized with this amount of hydroxide?

POST-LAB QUESTIONS -

1. Discuss the main sources of error in this experiment.

2. Sally Chemist is attempting to determine the mass % of acetic acid in vinegar using the experimental procedure described above. Below is an excerpt from her lab book:

a. Prepared vinegar analyte

25.0 mL vinegar

Mass of vinegar = 25.20 g

Added 75.0 mL H₂O

Added 2 drops phenolphthalein

Temperature: 27.0^oC

Manufacturer's mass % acetic acid = 3.5%

b. Prepared burette

Cleaned and dried burette

Filled with standardized NaOH solution 0.201 M

c. Titration

Initial burette reading: 5.12 mL

Final burette reading: 78.67 mL

Solution is light pink

Room temp unchanged.

i. What is the density of her vinegar sample?

ii. Use the manufacturers reported mass % acetic acid to estimate how many moles of acetic acid are present in her analyte.

iii. Use your result from ii to estimate how many mL of standardized NaOH solution she will need to reach the equivalence point.

iv. Use Sally's data to calculate the molarity of acetic acid in her vinegar sample.

v. Use the results from iv to calculate the mass % of acetic acid in Sally's vinegar sample.

vi. How would the following experimental errors affect Sally's experimental result?

DATA ANALYSIS -

1. Calculate the following for each trial and average the values:

a. Moles of NaOH used

b. Moles of acetic acid reacted

c. Mass in grams of acetic acid reacted

d. Molar concentration of acetic acid

e. Mass % of acetic acid

2. Calculate the percent error between your average experimental value of the mass % of acetic acid in vinegar and the manufacturer's reported mass % of acetic acid in vinegar.

Attachment:- Assignment Files.rar

Reference no: EM131924340

Questions Cloud

What is the stock expected return : What is the fundamental price of the stock? What is the stock's expected return?

Flexibility given state-contingent optimal action : What are the values of the project with flexibility given the state-contingent optimal action? What are the state equations and what is replicating portfolio.

Identify policy and system issues that contribute to problem : Identify policies and system issues that contribute to the problem, and identify the internal and external resources needed to address the issue.

What is the company current stock price : What is the company's current stock price? What is expected stock price in 5 years?

Why are you using phenolphthalein as an indicator : Lab - The Titration of Vinegar - Why are you using phenolphthalein as an indicator? Distinguish between the endpoint and equivalence point

Explain the potential impact of white privilege on clients : Explain the potential impact of white privilege on clients from both dominant and minority groups (consider impact of both positive and negative stereotypes).

Create change management plan for public health organization : In this assignment, you will create a change management plan for specific public health organization. Make recommendations based on the analysis of information.

Prepare proposal for tourism impact in national economy : You need to prepare proposal for Tourism Impact and Effective in National Economy and Investment

Examines how gender is presented in the news : This assignment examines how gender is presented in the news. This assignment involves identifying four relevant newspaper articles that illustrate a gender.

Reviews

len1924340

4/2/2018 2:00:13 AM

Detailed Question: Hello, Please solve pre lab and post lab questions, also, please complete the report sheet depending on my data. This is what my professor said. For this Lab, you will need to complete the worksheet and attach your pre- and post-lab questions." Also, please give me the calculations ways and explanations.

Write a Review

Required(*) Message

User Account

All Pages