Log in
Chemistry
1
answer
0
watching
266
views

The active ingredient of aspirin tablets is acetylsalicylic acid, which has a density of 1.4 g/cm3. In a lab class, a student used paper chromatography to isolate another common ingredient of headache remedies. The isolated sample had a mass of 0.384 g and a volume of 0.32 cm3. Given the data in the following table, what was the other ingredient in the headache remedy?

Watch
1
answer
0
watching
266
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Amarildo Kociaj
Amarildo KociajLv10
12 Nov 2020

Unlock all answers

Get 1 free homework help answer.
Already have an account? Log in
Share
discord banner image
Join us on Discord
Chemistry Study Group
Join now

Related textbook solutions

Basic Chemistry
5 Edition,
Timberlake
ISBN: 9780134138046
Principles of Chemistry Molecular Approach
4th Edition,
Tro
ISBN: 9780134112831
Principles of Chemistry Molecular Approach
3rd Edition, 2014
Tro
ISBN: 9780321971944
Chemistry: Structure and Properties
2nd Edition,
Tro
ISBN: 9780134293936
Chemistry: A Molecular Approach
3rd Edition,
Tro
ISBN: 9780321809247
Chemistry: A Molecular Approach
5th Edition,
Tro
ISBN: 9780134874371
Principles of Chemistry: A Molecular Approach
4th Edition,
Tro
ISBN: 9780134895741
Chemistry: The Central Science
14th Edition, 2017
Brown
ISBN: 9780134414232

Related questions

1.A block of metal has dimensions 5.00 cm x 2.50 cm x 3.00 cm. Calculate the volume of the block, showing the answer to the correct number of significant figures and unit.

2.If the block of metal from question 2 has a mass of 405.3 g, what is the density of the metal? Calculate the density, showing the answer to the correct number of significant figures and correct unit.

3.Convert the numerical value of the density in question 2 from units of grams per cubic centimeter (g / cm3) to milligrams per milliliter (mg / mL). Note:

-there are 1000 milligrams in a gram.

-the volume unit cubic centimeter cm3 equals the milliliter mL.

Keep the new density to the same significant figures as you reported in question 2

4.A finely-powdered white solid is known to be homogeneous mixture rather than a pure substance. A sample of this solid completely dissolves in water. Give TWO possible substances that could make up this solid mixture, and briefly explain your choices.

5.If your percent SALT in Lab 2 is relatively low, it can be assumed that some salt did not go into the filtrate (the liquid that passes through the filter paper), but rather may have been trapped with the sand. Explain briefly how you could recover any of this "missing" salt?

6.A brand of aspirin claims to contain 325 mg (1 g = 1000 mg) of aspirin per tablet. In addition to pure aspirin, a tablet also contains a non-active filler. We assume that the tablet contains only these two components: aspirin and filler. If a single tablet weighs 1.17 g, calculate the percent filler. Hint: calculate percent aspirin FIRST using the formula

% aspirin = [ (mass aspirin ÷ mass tablet) x 100], the find % filler. When using this formula, make sure the masses of aspirin and tablet have the same units.

7.Water has a density of 1.00 g/mL, and chloroform has a density of 1.49 g/mL. These two liquids do not mix with each other, but rather, form two layers when combined.

8.Equal volumes of water and chloroform are placed in a beaker. A piece of nylon is dropped in the beaker, and is seen to float the the interface (the boundary) of the two liquid layers.

Give a possible value for the density of nylon, including the correct units. Explain your answer briefly.

9.A procedure similar to that used in Lab 3 was performed to find the density of cyclohexane, which has an actual density of 0.779 g/mL, Due to poor lab technique, an experimental density of only 0.663 g/mL is found. Calculate the percent error for the density. Give your answer to the correct number of significant figures.

10.Two white powders are given to you. One is pure sodium bicarbonate, and the other is baking powder (a mixture of sodium bicarbonate and a weak acid like citric acid). Which single test (NOT counting the visual examination with a hand lens) used in Lab 3 allows you to distinguish sodium bicarbonate from baking powder? Explain your answers completely.

11.Gold has a specific heat of 0.129 J/goC. If a piece of gold (initially at 10.0oC) is dropped into hot water, the final temperature of both the gold and the water is measured as 70.9oC. If it is known that 4560 J of heat transferred from the hot water to the gold, what is the mass of the piece of gold in grams? Give your answer to the correct number of significant figures.

12.It is stated in the Introduction to Lab 4 that qwater = -qmetal. This equation means that if a hot piece of metal is placed in water, the amount of heat given off by the metal is exactly equal to the amount of heat absorbed by the water. However, this equation is not always accurate, because not all of the heat from the metal necessarily goes to the water. Where else can some of the heat go if it is not absorbed by the water?

13.A certain brand of breakfast cereal claims to have 100 Calories per 28 gram serving. 150.0 grams of cereal are burned using a procedure similar to that used in Lab 4. How many calories of heat are released? Note 1 food Calorie (capital C) = 1000 heat calories (lower case c)

14.The oxalate anion C2O42- is found in many dark green vegetables, including spinach, swiss chard, and collard greens. When cations react with oxalate, the resulting ionic compounds are insoluble in water except Group I A oxalates (e.g. compounds of lithium, sodium, potassium, etc. and oxalate) and ammonium oxalate (NH4)2C2O4. These exceptions are soluble in water.

15.Spinach leaves are cut into small pieces, mashed with small amounts of boiling water, and filtered through filter paper to remove the insoluble spinach material. The resulting aqueous extract contains the oxalate anion.if a small amount of the spinach extract is mixed with a small amount of a calcium acetate solution, Ca(C2H3O2)2(aq), what do you expect will be observed?

16.If a small amount of the spinach extract from question 16 is mixed with a small amount of a potassium acetate solution, KC2H3O2(aq), what do you expect will be observed?

17.If a hot water extract of another vegetable is mixed with calcium acetate solution and a white precipitate is observed, does this automatically indicate the presence of the oxalate anion in this vegetable? Explain your answer.

Exp. 11 (2 meetings): Synthesis of Aspirin and Melting Point Determination

1. What is the melting point range of your aspirin sample?

2. What were the results of your FeCl3 tests when you compared the aspirin you made to the commercial aspirin?

3. Do the results of your melting point determination agree with the results from your FeCl3 test? Explain.

POST-LAB QUESTIONS:

1. Give two physical properties you observed in your crude (unpurified) aspirin sample.

2. If the theoretical yield of a reaction was calculated to be 3.11g and the actual yield was 2.65g, what was the percent yield for the reaction? Show formula and all work.

3. If a melting point range is greater than 3o C, such as 119.5o C to 125.8o C, what can you say about the sample?

Determinatrion of Iron in Vitamin

A. Prep of Iron Soln. from Vitamin

Weigh three vitamin tablets and place each tablet in separate 125-mL Erlenmeyer Flask. Add 25 mL of 2M HCL to each flask in the hood and boil the samples for 15 mins.

Set up Vacumm filter system and filter each sample serparetely and collect the filtrate(liquid). Transfer filtrate after each run to a 50 mL Volumetric flask. Rinse filter flask with DI water and transfer rinse to the vol. flask as well. Repeat for each solution.

After solutions cool, dilute it to the mark with DI water and Mix well. Transfer contents to a labeled beaker.

For each solution made, transfer 1.00 mL of the solution with a volumetric pipette and place it in a fresh 50 mL vol. flask. Then dilute it ot he mark with DI water.

B. Prep of sample Solutions

From each diluted vitamin solution a test solution sample will be made. Using a vol. pipette transfer 5.00 mL of the diluted vitamin solution(unknown molarity) to a large test tube. Then add 4.00 mL hydroquinone and 6 mL of o-phenanthroline to the test tube with a vol.pipettes. Note the volume of the test solutions. This dilution step is needed when calculate the mass of iron in the tablets.

C. Prep of Sample Solutions

One iron standard solution will be made for the class.

D. Prep of Calibration Solutions

Each student pair will make at least one calibration solution. Have the instructor assign you a solution 0-7. The entire lab section will make one calibration set by the following steps:

Label a 50.00 mL vol. flask with your assigned number (0-7)

Collect ~ 5 mL of hydroquinone and transfer it to a clean beaker. Then collect ~ 5 mL of phenathroline and transfer this solution to another clean beaker. Transfer 2.00mL of hydroquinone and 3.00mL of phenathroline using vol. pipettes to the labeled vol. flask

Collect ~5-10 mL of the standard solution and transfer it to a clean beaker. The amount of iron solution to transfer via vol. flask is equal to the assigned number (i.e. if your group was assigned #1, transfer 1.00 mL of the iron solution to the flask. Flask 0 will not contain any iron solution.

Once all three reagents have been added to a flask. Add ~ 20mL of DI water. Mix the solution by capping the flask and inverting it several times. Continue adding DI water to the mark on the flask and mix solution again by inversion.

What is the molarity of the iron in each calibration solution?

Given Info/Data

Mass of Iron in Tablet from bottle (mg) 18
Mass of Iron for Stock Soln. (g) 0.1435
Molar Mass of Fe(NH4)2(SO4)2• 6H2O (g/mol) 392.14
Molar Mass of Fe (g/mol) 55.845
Moles of Iron Stock Solution (mol) 0.000365941

Mass of Iron tablets: 1.2900g 1.2991g 1.2979

Weekly leaderboard

Home
Homework Help 3,900,000
Chemistry 830,000
Start filling in the gaps now
Log in