100+ Master’s Level Experts in Chemistry And Related Subjects Will Do Your Written Homework in 3-6 Hours

No matter what kind of academic paper you need, it is simple and secure to hire an essay writer for a price you can afford at Chemhomeworkhelp. Save more time for yourself.

1

HAPPY CUSTOMERS

%

SATISFACTION RATE

ACTIVE WRITERS

Basic features

  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support

Ondemand options

  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading

Paper Format

  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Affordable prices

HIGH SCHOOL
FROM

$10 / PAGE

COLLEGE
FROM

$13 / PAGE

Our prices depend on the urgency of your assignment, your academic level, the course subject, and the length of the assignment. Basically, more complex assignments will cost more than simpler ones. The level of expertise is also a major determinant of the price of your assignment.

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

 

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
$26

Chemistry Homework Help- Chemistry Answers

College students looking for chemistry homework help tend to find specific topics uncomfortable and difficult to comprehend. Hiring experts online becomes the best option as they provide comprehensive and procedural solutions enabling students to grasp readily. Besides, it results in the submission of top-quality chemistry assignments suitable for students to score excellent grades in the subject. If you find any chemistry assignment tricky and with the potential to earn you undesirable grades, considering chemistry homework help online is essential.

With chemistry homework help, students get a seamless approach to submitting flawless and high-quality papers that significantly boost their overall score. Yet, it is essential to learn about a platform that delivers the best chemistry assignment help services. Here is what to know about an online assignment help service that gives first-rate chemistry solutions.

 

Get Quality Chemistry Homework Help Online

Most students term chemistry as an intriguing science subject full of exigent formulas, atoms, elements, chemicals, molecules, and compounds. Some students even find the subject challenging during the introductory period before getting to study independent concepts. Such a reputation has led students often asking, ‘can you do chemistry homework and deliver good quality papers?’ to anyone capable of helping them.

Chemhomeworkhelp.com understands such scenarios hence comprises a well-informed, passionate, and experienced team of chemistry helpers. They understand the chemistry subject well and can provide homework help to students seeking professional chemistry help online. Our chemistry experts can handle the assignment efficiently while providing explanations for a better understanding. Coupled with perfectly formatted, unique, and immaculate chemistry papers, you get top-quality chemistry papers that earn you the grade you desire.

 

Find Chemistry Help for All Your Chemistry Problems with Ease

Several chemistry homework help platforms promise to deliver the best services, but a few keep their end of the bargain. Unlike such services, Chemhomeworkhelp.com never disappoints whenever you need help with chemistry homework on our platform. But what makes us unique from the competition?

  • Guaranteed Excellent Grades: Different students have varying chemistry assignments that can affect their final results when they score low. Our chemistry homework helper can help submit the best paper for top grades.
  • Money-Back Guarantee: Whenever you pay for chemistry assignment help, you expect the best worth your money. Chemhomeworkhelp.com ensures you get the best service; if not, we’ll refund your money. We also offer refunds if you make double payments to ensure you are always satisfied with us.
  • Save Time: Getting research materials and finding time to write your paper can be time-consuming. The best approach is hiring an expert to help you with such instances and save you valuable time.
  • 24/7 Customer Support: When getting help with chemistry homework, you may, at times, require detailed solutions from company representatives. We ensure you get prompt customer support as we have reliable customer support to answer queries and complaints around the clock.

 

Untitled design 26

Find the Best Chemistry Homework Helpers for Your Chemistry Tests and Exams

Typically, most students find chemistry subject overwhelming, more so when assigned assignments that seem undoable. Some even have a bad attitude towards the subject, making it even harder to solve simple tests. This is the primary reason why most of them opt for chemistry homework help websites that offer such services.

When you hire the right platform, you gain access to the best chemistry tutor or helper who can make the subject enjoyable, simple, and exciting. Notably, you’ll get new ideas on how to handle such problems prepared procedurally. Online chemistry tutors can provide stepwise approaches while allowing you to get detailed explanations on some topics you find problematic. In turn, students can attend different chemistry exams and score high in this subject.

The Process of Paying Someone to Do My Chemistry Homework for Me

If the deadline is imminent and you have a chemistry assignment yet to be completed, hiring an expert becomes the best possible solution. But you can become confused wondering how to access professionals at Chemhomeworkhelp.com. The process is straightforward, whether you need high school or college chemistry homework help. However, paying our exerts depends on your assignment’s nature; soft copy, hard copy, or online class.

  • Soft Copy Chemistry Assignment: If you have a soft copy assignment in PDF, word document, or any other format, you can readily attach your chemistry assignment through the order form or mail it to us. Our customer support will evaluate your assignment and provide a quote. After payments, a chemistry paper will get to work on your paper immediately.
  • Hard Copy Assignments: For hard copy chemistry assignments, you need to take a clear and high-quality photo of the homework and attach it through our order form. In case you experience any difficulties, feel free to contact us for assistance.
  • Chemistry Online Classes: We also offer online classes for chemistry problems, which are solved in real-time. With this, you need to provide your login credentials, and we’ll assess your assignment and later provide a price quote. After settling your payments, our chemistry tutors will work on your assignment and deliver within your timeframe.

Finding Chemistry Homework Help Is Easy.

Today, chemistry homework help has become an essential tool for students to succeed in the subject. This is because online chemistry helpers simplify existing problems, making them seem simpler. Sequentially, students discover effective means of handling such problems and score high grades.

So, the next time you say, ‘I need help with my chemistry homework,’ Chemhomeworkhelp.com is the place to be as you’ll never regret choosing us. Let us know what you need, and we’ll gladly assign our proficient writers specializing in the topic to handle the problem for you. That said, our chemistry experts can provide below academic help within the subject.

Help with Analytical Chemistry Homework

Analytical chemistry is an approach used in science to determine a given substance or material’s chemical composition. It involves loads of lab work to separate, extract, residue, and filtrate while using different instruments to analyze either qualitative or quantitative. Lab reports hence come in to showcase your results to your professor. If you find it hard to do so, Chemhomeworkhelp.com can help you submit the best lab report.

Help with Physical Chemistry Homework

This is where physics interacts with chemistry, and students unfamiliar with physics basics are likely to fail. Typically, this chemistry concept focuses on molecular levels and energy exchange, which are the most difficult assignments. When you face such problems, the first thing is trying to learn where to get help with chemistry homework and get the grades you desire. We can help you understand the principles of physics chemistry and submit quality assignments.

Help with Quantum Chemistry Homework

It is no doubt quantum chemistry is the most complex topic as it combines both theory and lab reports, including quantum mechanics and physical models. It also includes computation chemistry and quantum theories, atoms and molecules. When assigned a quantum chemistry homework, you may become bemused and begin searching ‘quantum homework help chemistry,’ intending to find helpers online. Save the hassle and stress and hire a quantum chemistry expert at Chemhomeworkhelp.com.

Help with Organic Chemistry Homework

Organic chemistry is the study of organic compounds, including finding individual structures and learning how they react. Several organic concepts, such as planar geometry and hybridization, are challenging to students. With this, it requires organic chemistry homework help to enable students to ease through complex concepts. Chemhomeworkhelp.com consists of organic chemistry tutors to provide real-time solutions and written solutions from our top-rated chemistry helpers.

Help with Inorganic Chemistry Homework

Homework help high school chemistry, including colleges and universities, applies to inorganic chemistry, which involves compounds without C-H bonds. Like organic chemistry, students struggling with inorganic chemistry assignments can use our services to get prompt solutions from our experts. Chemhomeworkhelp.com hires the best team to ensure you get the best from us for inorganic chemistry assignment help.

Help with Chemistry Homework on Any Topic

Several other chemistry topics, including polymer chemistry and surface chemistry, can be uncomfortable to students. At Chemhomeworkhelp.com, we can help you get through any topic as we have highly qualified and chemistry experts on our platform. Besides, we offer chemistry homework help chat that ensures we remain in touch with your writer or interact with a chemistry tutor swiftly.

Can You Make My Homework Look Better?

Nothing makes Chemhomeworkhelp.com stand out in the industry than delivering premier chemistry assignments to students from different study levels. Whether you need AP chemistry homework help or have a problem with particular topics, we are who call. We have the best writers who provide procedural solutions to the problems while writing it perfectly without any grammatical errors. Besides, we provide comprehensive checking, editing, and proofreading services to guarantee authentic and flawless assignments even when you seek chemistry homework help balancing equations.

That said, yes! We can make your homework better and with higher chances of earning better grades. Our online chemistry tutors also play a vital role in providing real-time solutions to assignments on our websites, unlike using a chemistry help app. Chemhomeworkhelp.com, therefore, is the best platform that gives the best chemistry homework help in the industry.

Chemistry homework help has proven to become essential for students finding specific chemistry assignments tricky. Besides, it accompanies several benefits than getting top-quality papers to earn an A or B in the overall score. Chemhomeworkhelp.com, therefore, remains the right platform that gives unrivaled chemistry homework solutions to different students.

Delivery

We know how important any deadline is to you; that’s why everyone in our company has their tasks and perform them promptly to provide you with the required assistance on time. We even have an urgent delivery option for short essays, term papers, or research papers needed within 8 to 24 hours.

We appreciate that you have chosen our cheap essay service, and will provide you with high-quality and low-cost custom essays, research papers, term papers, speeches, book reports, and other academic assignments for sale.

24/7 support

We provide affordable writing services for students around the world. That’s why we work without a break to help you at any time, wherever you are located. Contact us for cheap writing assistance.

"; Spectrophotometric Determination Of An Equilibrium Constant Lab Report - Chem Homework Help
Spectrophotometric Determination of An Equilibrium Constant Lab Report

Introduction:

Colorless substances transmit all of the visible wavelengths of light. Colored substances on the other hand absorb certain wavelengths of light in the visible region and transmit other wavelengths. Complex ions such as thiocyanato iron (III) ion (Fe(SCN)2+) absorb light in the visible range. The complementary color is transmitted at a particular wavelength.

A spectrophotometer is an instrument that measures the amount of light absorbed or transmitted by a solution at a particular wavelength. A spectrophotometer consists of a light source, a wavelength selecting device, a means of passing light through a sample and a detector to measure the transmitted light. Transmittance (T) is the ratio of intensity (I) of light passing through a medium to the intensity of light before encountering the medium (Io).

% T =I/ Io (eqn. 1)

Where %T is the percent transmittance, I is the intensity or amount of light that is transmitted through the sample and Io is the intensity or amount of light transmitted through the blank. The reference blank doesn’t absorb light and has 100% transmittance. The absorbance, A, of an ideal solution is directly proportional to the concentration of absorbing species and is given by

A = – log I/Io = 2.000 – log (%T) (eqn. 2)

Absorbance is directly related to the concentration of a sample and path length through the sample and the relation is given by the Beer’s law.

A = bC (eqn. 3)

Where C is the molar concentration of the sample, b is the path length of light through the sample and is the molar absorptivity of the absorbing species at a particular wavelength. The unit of is L.mol-1.cm-1 and is constant for a particular absorbing species and depends on the solute, solvent and , the wavelength. is a measure of how strongly a chemical species absorbs light at a given wavelength. Absorbance maximum (max) for Fe(SCN)2+ is 447 nm and %T will be measured at this wavelength.

In this experiment, you will study the reaction between aqueous iron (III) nitrate, Fe(NO3)3, and potassium thiocyanate, KSCN. The two chemicals react to produce a blood-red complex Fe(SCN) 2+, the absorbing species. We will be recording the % transmittance of samples as %T scale is linear and hence provides more precise results than the absorbance scale. The %T is measured in the range of ~25-85% transmittance for a series of five different equilibrium solutions and absorbance values calculated. Absorbance of Fe(SCN) 2+ is directly proportional to the concentration of Fe(SCN) 2+ .

In Part 1 of the experiment, you will prepare a Beer’s law plot – a calibration curve based on absorbance values for solutions of known concentrations (standard solutions). Beer’s Law plot is a straight line plot and slope of the straight line gives the molar absorptivity (). Knowing the absorbance of a solution, the calibration curve can be used to determine the unknown concentration of FeSCN2+.

(eqn. 4)

The equilibrium constant for the above reaction is given by

(eqn. 5)

In Part 1, we will add a very high concentration of Fe3+ to a small initial concentration of SCN ([SCN]i). The [Fe3+] in the standard solution is 100 times larger than the [SCN]i in the equilibrium mixtures. According to Le Chatelier’s principle, this high concentration forces the reaction far to the right, using up essentially all of the SCN ions. According to the balanced equation, for every one mole of SCN reacted, one mole of FeSCN2+ is produced. Thus, equilibrium moles [FeSCN2+] eq are assumed to be equal to initial moles [SCN] i.

This is true only for the Beer’s Law standard solutions.

Equilibrium moles Fe(SCN) 2+ = initial moles SCN(eqn. 6)

[Fe(SCN) 2+]* Vtot = [SCN]I * Vi (eqn. 7)

[Fe(SCN) 2+] = [SCN]iVi /Veq (eqn. 7)

In Part 2 of the experiment, varying amounts of KSCN will be combined with a less concentrated Fe(NO3)3 solution to obtain varying amounts of FeSCN2+.

The amount of product formed at equilibrium, [FeSCN2+] eq, will be determined from the calibration graph prepared in Part 1 and absorbance values obtained in Part 2.

Knowing the [Fe(SCN) 2+]eq allows us to determine the concentrations of the other two ions at equilibrium. The equilibrium concentration of [Fe3+] eq is the initial concentration of [Fe3+] i (after dilution) minus the amount of [Fe (SCN) 2+] eq (obtained as indicated above) and given by the following equation.

[Fe3+] eq = [Fe3+] i – [FeSCN2+] eq (eqn. 7)

The [Fe (SCN) 2+] eq is determined by using absorbance and the Beer’s Law calibration curve. [SCN]eq is determined by using the following equation.

[SCN] eq = [SCN] i – [FeSCN2+] eq (eqn. 8)

Knowing the values of [Fe3+] eq, [SCN] eq, and [Fe (SCN) 2+] eq you can calculate the value of Kc, the equilibrium constant by using equation 5. Average value for the equilibrium constant is determined from the five measurements.

Supplies:

0.0020 M iron (III) nitrate, Fe(NO3)3, solution in 1.0 M HNO3

0.200 M iron (III) nitrate, Fe(NO3)3, solution in 1.0 M HNO3

0.00200 M potassium thiocyanate, KSCN

Spectrophotometer

5.0 mL pipette

3.0 mL pipette

plastic cuvettes

pipet pump or bulb

Burette (2)

Burette clamp

20 × 150 mm test tubes (6)

distilled water

test tube rack

50 mL volumetric flask (5)

Thermometer

Procedure:

Part 1 – Plotting the Beer’s Law plot

Table 1 below provides the volumes of reactants needed to prepare the standard solutions for the calibration curve. Accurately prepare the six solutions according to the volumes listed in the table below. Use a 5.00 pipette to deliver 0.200 M Fe(NO3)3 solution and burettes to deliver KSCN solution and water into a 50 mL volumetric flask. Cap the flasks tightly and mix each solution thoroughly by inverting the flask 10 times.

Table 1: Reagent quantities for calibration curve.

Solution

0.00200 M KSCN

0.200 M Fe(NO3)3

DI water

1

0.0 mL

5.0 mL

Fill to the line

2

1.0 mL

5.0 mL

Fill to the line

3

2.0 mL

5.0 mL

Fill to the line

4

3.0 mL

5.0 mL

Fill to the line

5

4.0 mL

5.0 mL

Fill to the line

6

5.0 mL

5.0 mL

Fill to the line

Measure and record the temperature of one of the above solutions to use as the temperature for the equilibrium constant.

Set the wavelength on the Spectrometer to 447 nm. Use solution 1 as the reference blank and fill an empty cuvette ¾ full of solution 1. Place the blank in the spectrophotometer and follow the instructions for using the spectrophotometer.

Fill a new cuvette, ¾ full with solution 2. Record the % transmittance and discard the solution in the cuvette into the waste beaker.

Recheck the blank solution from step 4 for 100% transmittance.

Next fill the cuvette from step 4 with solution 3 and determine the % transmittance.

Follow the procedure in step 5 & 6 for the remaining three solutions. You may use the same cuvette so long as you measure the transmittances from dilute to concentrated solutions.

Rinse the cuvettes with tap water followed by distilled water 3 times and place in the used clean cuvette bin.

Dispose of your equilibrium solutions into the waste container provided.

Calculate the absorbance values for the five solutions and plot an Excel plot, with absorbance on the y-axis and concentration of [Fe(SCN)2+] on the x-axis. Label the axis appropriately and provide a title for the graph. Concentrations of [Fe(SCN)2+] are calculated based on concentrations of KSCN. Construct a calibration curve for the data collected in Steps 4 through 7. Draw a best-fit line though the data points. Report the equation of the line and the R2 value on the graph.

Staple a printout of the data along with Excel graph to your data sheet. This graph will be used to determine the amount of the complex formed in Part 2 of the experiment.

Part 2: Determination of the equilibrium constant

Clean and dry 6 large test tubes and label them Blank & A-E.

Use a 3.00 mL pipette to deliver 0.0020 M Fe(NO3)3 solution and burettes to deliver the required volumes of KSCN solution and DI water into clean and dry test tubes. Note that this set of combinations uses the more dilute Fe(NO3)3 solution (0.002M). Stir each solution with a glass stir rod to mix the reagents.

Trial

Volume

0.0020 M Fe(NO3)3 (mL)

Volume

0.0020 M KSCN (mL)

DI water (mL)

Table 2: Volumes and concentrations of solutions for determining the equilibrium constant

Trial

Volume

0.0020 M Fe(NO3)3 (mL)

Volume

0.0020 M KSCN (mL)

DI water (mL)

Blank

3.00

0.00

7.00

A

3.00

2.00

5.00

B

3.00

3.00

4.00

C

3.00

4.00

3.00

D

3.00

5.00

2.00

E

3.00

6.00

1.00

Measure the % transmittance of each equilibrium solution following the same steps as in Part I, steps 3 through 7.

NOTE: You are not making a graph this time. Simply record the % transmittance values in your data table for further analysis.

Rinse the cuvettes with tap water followed by distilled water 3 times and place in the used clean cuvette bin.

Dispose of your equilibrium solutions into the waste container provided, clean the test tubes with soap and water, rinse twice with tap water and twice with distilled water. Place clean test tubes in the “used clean test tube bin”

NAME: ____________________________ DATE: ___________

Partner: ___________________________

Data Sheet & Calculations.

Part I:

For this part of the experiment assume [SCN]i = [FeSCN2+]

Table 3:

Trial

% Transmittance

[SCN]i

[Fe(SCN)2+]

Absorbance

2

3

4

5

6

Calculate the [SCN]i and [Fe3+]i accounting for dilution using McVc = MdVd, for each solution in Table 1. Show one sample calculation for absorbance, [SCN] and [FeSCN2+]. Enter all calculated values into Table 3 above.

Absorbance: Use Eqn. # 2 (2.000 – log (%T))

Dilution Formula

[SCN-]i

[FeSCN2+] _______________________________

[Fe3+] >> [SCN]; equilibrium in eqn. 4 is far to the right, using up essentially all of the SCN ions. For every one mole of SCN reacted, one mole of FeSCN2+ is produced. Thus, equilibrium moles and molarity of FeSCN2+eq are assumed to be equal to initial moles SCNi.

Graph:

Plot Absorbance vs. [FeSCN2+] from the data from Table 3 above & fit a trendline.

Print a well-labeled graph with a complete Data Table, showing original data and calculated and graphed values. Report the trendline equation along with the R2 value.

Part II: Data and Calculations

Table 4:

Trial

% Transmittance

Absorbance

A

B

C

D

D

E

Calculate the absorbance and complete Table 4 above.

Calculate the initial concentrations of SCN and Fe3+ in the test tubes A-E (Table 2). Show two sets of calculations and complete Table 5 below.

Table 5. Initial Concentrations of SCN and Fe3+

Test tube #

A

B

C

D

E

[SCN]i
[Fe3+]i

Use the calculated absorbance values from Table 4 in Part II (y values) and the best-fit line equation from Part I to calculate the [FeSCN2+]eq at equilibrium. Show two sets of calculations and complete Table 6 below.

Sample Calculation

with hypothetical values

of Absorbance from Table 4

& fitted eqn. from Table 3

y = mx + b (y is absorbance)

0.0620 = 2000x -0.0250

x = 0.0620 + 0.0250

2000

= 4.35 x 10-5

Use the trendline equation from Table 3 and calculate value of x = using absorbance values from Table 4

Table 6. Equilibrium concentration of [FeSCN2+]eq

Test tube #

A

B

B

C

D

[FeSCN2+]eq

These are ICE Table calculations

Initial [Fe3+]initial [SCN]initial 0.00

Change – [FeSCN2+]eq – [FeSCN2+]eq + [FeSCN2+]eq

Equilibrium [Fe3+]eq [SCN]eq [FeSCN2+]eq

Calculate the equilibrium concentrations for Fe3+ and SCN for the mixtures in test tubes A-E. Use the equations 7 & 8 respectively. Give two examples of your calculations and complete Table 7 below.

Initial 0.00

Change

Final

Table 7. Equilibrium concentrations of SCN and Fe3+

Test tube #

A

B

C

D

E

[SCN]eq

[Fe3+]eq

[FeSCN2+]eq

Calculate the value of Keq (eqn. 8) based on equilibrium concentrations of SCN , Fe3+ and FeSCN2+ solutions. Show two sample calculations and complete Table 8 below.

(Sample Exercise 15.7 from Test Book)

Table 8. Keq

Test tube #

A

B

C

D

E

Average

Keq

Spectrophotometric Determination of an Equilibrium Constant

NAME: ____________________________________ Date: _____________

Post-Laboratory Assignment

A student determined the molar absorptivity () to be 4800 L/mol.cm for the thiocyanatoiron (III) ion. What is the % T for a solution that is 1.2 X 10-4 M in thiocyanatoiron (III) ion? The path length for the light is 1.00 cm?

Assuming that the equilibrium concentration of [FeSCN2+] is 6.08 x 10-5 M in a solution that initially was 1.00 x 10-3 M in Fe3+ and 2.00 x 10-4 M in SCN, calculate the equilibrium concentrations of Fe3+ and SCN and the value of Keq.

Review Sample Exercise 15.8 for solving this problem

Initial 0.00

Change + 6.08 x 10-5

Final 6.08 x 10-5

At a given temperature, the Keq for the systems studied in this experiment is 1.4 x102. Suppose 100.0 mL of 2.00 x10-3 M KSCN was mixed with 100.0 mL of 2.00 x10-3 M Fe(NO3)3 . Calculate the equilibrium molar concentration of thiocyanatoiron (III) ion? Show complete calculations (you may have to solve a quadratic as the assumption that x << initial concentrations of Fe3+ and SCN may not be valid)

Calculate the concentrations by the dilution formula.

Review Sample Exercise 15.11 for solving this problem (K < 103)

Initial

Change -x -x +x

Final x

Spectrophotometric Determination of an Equilibrium Constant

Pre-Laboratory Assignment

NAME: __________________________________ DATE: _____________

Why is the experiment run at a wavelength of 447 nm?

Why is the Fe3+ concentration so much higher than the KSCN in Part 1 of the experiment?

If the percent transmittance of a solution is 82.7 what is the absorbance of that solution?

What is the relationship between concentration and absorbance in Part 1 of the experiment?

If the concentration of the solution in question 3 above is 2.50 x 10-3 M, calculate the value of molar absorptivity of the solution.

Order a unique copy of this paper
(550 words)

Approximate price: $22