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.






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


$10 / PAGE


$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:

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.


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.

"; Decomposition Of Hydrogen Peroxide.pdf - Chem Homework Help
Decomposition of Hydrogen Peroxide.pdf

Experiment 2 Decomposition

of Hydrogen Peroxide
The decomposition of hydrogen peroxide in aqueous solution proceeds very slowly. A bottle of
3% hydrogen peroxide sitting on a grocery store shelf is stable for a long period of time. The
decomposition takes place according to the reaction below.

2 H2O2(aq) → 2 H2O + O2(g)

A number of catalysts can be used to speed up this reaction, including potassium iodide,
manganese (IV) oxide, and the enzyme catalase. If you conduct the catalyzed decomposition of
hydrogen peroxide in a closed vessel, you will be able to determine the reaction rate as a function
of the pressure increase in the vessel that is caused by the production of oxygen gas. If you vary
the initial molar concentration of the H2O2 solution, the rate law for the reaction can also be
determined. Finally, by conducting the reaction at different temperatures, the activation energy,
Ea, can be calculated.

In this experiment, you will

· Conduct the catalyzed decomposition of hydrogen peroxide under various conditions.
· Calculate the average rate constant for the reaction at room temperature.
· Determine the rate law expression for the reaction.
· Calculate the activation energy for the reaction.

The rate law for this reaction can be determined using the observed rates of reactions from a
series of different experiments. The concentration of one reactant is held constant between two
different experiments, acting as the control, while the concentration of the second reactant is
different between the two experiments. The rate of reaction is measured in each experiment so
the impact of changing the concentration of the second reactant can be determined. The order of
the reaction with respect to each reactant is determined in this fashion and once the order of each
reactant is know the rate law can then be written.

(A) Sample Exercise for Determining Reaction Order

Consider the following reaction: (CH3)3CBr(aq) + OH-(aq) → (CH3)3COH(aq) + Br-(aq)
A series of experiments is carried out with the following results:

Exp 1 Exp 2 Exp 3 Exp 4 Exp 5
[(CH3)3CBr] 0.50 1.0 1.5 1.0 1.0
[OH-] 0.050 0.050 0.050 0.10 0.20
Rate (M/s) 0.0050 0.010 0.015 0.010 0.040

Find the order of the reaction with respect to both (CH3)3CBr and OH-.

Advanced Chemistry with Vernier 1

2 Advanced Chemistry with Vernier

To find the order of the reaction with respect to (CH3)3CBr, choose two experiments, 1 and 3 for
example, where [OH-] is constant. A similar approach can be used to find the order of the
reaction with respect to OH-, comparing experiments 2 and 5, where [(CH3)3CBr]

(1) Order with Respect to (CH3)3CBr:

Rate exp 3 = k([(CH3)3CBr]exp3)m ([OH-]exp3)n
Rate exp 1 k([(CH3)3CBr]exp1)m ([OH-]exp1)n

0.015 M/s = k([1.5 M])m (0.050 M)n simplifies to: 3.0 = (3.0)m
0.0050 M/s k([0.50 M])m (0.050 M)n

Using the natural log applied to both sides and solving for “m”

Ln 3.0 = (Ln 3.0) (m) (Ln 3.0) / (Ln 3.0) = 1.10 / 1.10 = 1 = m

Since “m” = 1 the reaction is first order with respect to (CH3)3CBr.

(2) Order with Respect to [OH-]:

Rate exp 5 = k([(CH3)3CBr]exp5)m ([OH-]exp5)n
Rate exp 4 k([(CH3)3CBr]exp2)m ([OH-]exp2)n

0.040 M/s = k([1.0 M])m (0.20 M)n simplifies to: 4.0 = (2.0)n
0.010 M/s k([1.0 M])m (0.10 M)n

Using the natural log applied to both sides and solving for “m”

Ln 4.0 = (Ln 2.0) (m) (Ln 4.0) / (Ln 2.0) = 1.39 / 0.69 = 2.01 = n

Since “n” = 2 the reaction is second order with respect to (CH3)3CBr.

Now that the order of the reaction for each reactant has been determined the rate law can be
written for this equation:

Rate = k [(CH3)3CBr] [OH-]2

(B) Sample Exercise for Determining Molarity of a Diluted Solution

When two solutions are mixed in an experiment the total volume of the solutions is increased and
the concentration of each solution is diluted. Recall:

Moles solute before dilution = moles solute after dilution

so; (Molarity)conc x (Volume) conc = (Molarity)dil x (Volume)dil

The Decomposition of Hydrogen Peroxide

Advanced Chemistry with Vernier 3

What is the concentration of each compound when 6.0 mL of a 0.60 M solution of H2O2 is mixed
with 2.0 mL of a 0.25 M potassium iodide solution?

(1) First consider the total volume of the solution after mixing:

6.0 mL H2O2 + 2.0 mL KI = 8.0 mL total volume of diluted solution

(2) Determine the concentration of H2O2 after mixing:

[0.75 M]conc x (6.0 mL) conc = [H2O2]dil x (8.0 mL)dil

(0.60 M)(6.0 mL) / (8.0 mL) = 0.45 M = [H2O2]dil

(3) Determine the concentration of KI after mixing:

[0.25 M]conc x (2.0 mL) conc = [H2O2]dil x (8.0 mL)dil

(0.40 M)(2.0 mL) / (8.0 mL) = 0.10 M = [KI]dil

The concentration of the H2O2 decreased from 0.60 M to 0.45 M and the concentration of KI
decreased from 0.25 M to 0.10 M after the two solutions are mixed. The solutions will be
diluted as the reactions begin so be sure to use the diluted concentrations of each reactant when
determining the reaction orders or rate constants.

(C) Sample Exercise for Converting Pressure Rate Data to Molarity Units

The data rate recorded in this experiment is in kilopascals per second (kPa/s). Since pressure is a
unit of concentration in the gas phase it can be used to determine rate when the change of
pressure is measured over the change in time. However, in this experiment the reactants are in
the aqueous phase and the concentration unit for the solutions is in molarity (M). kPa/s can be
converted to M/s by using a derivation from the ideal gas law:

Molarity = P / RT

In which P = kPa/s, R = 8.314 L * kPa / K*mol (one of ideal gas constants), and T = temperature
on Kelvin.

In one experiment the rate of O2 production was 0.22 kPa/s when the temperature of the water
bath was 19.0 oC. What is this rate in M/s?

Molarity = (0.22 kPa/s) / (8.314 L*kPa/K*mol)(292.0 K) = (0.22 kPa / 2.43 x 103 L*kPa / mol)

Molarity = 9.05 x 10-5 M/s

The units kPa and Kelvin cancel leaving mol/L*s or M/s.

(D) Sample Exercise for Converting Percent Solutions (mass/volume) to Molarity Units

Assumed 100 mL of total volume of solution in a percent (mass/volume) solution and the percent
value will represent the grams of solute dissolved in water to make a total volume of 100 mL.
For example a 10% NaCl solution will have 10 g of NaCl dissolved in 100 mL of solution.

What is the molarity of this 10% NaCl solution?

4 Advanced Chemistry with Vernier

Molarity = moles of solute / liters of solution

If you assume 10 g NaCl and 100 mL of solution and the molar mass of NaCl is 58.5 g / mol

(1) Moles NaCl = (10 g NaCl)(1 mole NaCl / 58.5 g NaCl) = 0.17 moles NaCl

(2) Liters solution = (100 mL solution)(1 L solution / 100 mL solution) = 0.100 L solution

(3) Molarity = (0.17 moles NaCl / 0.100 L solution) = 1.7 M

Diagram of the equipment set for this experiment:

Figure 1

Vernier computer interface 3% hydrogen peroxide, H2O2, solution
distilled water 0.5 M potassium iodide, KI, solution
Vernier Gas Pressure Sensor 18 × 150 mm test tube
thermometer or Temperature Probe two 10 mL graduated cylinders
one-hole rubber stopper with stem graduated plastic Beral pipet
tubing with two Luer-lock connectors 1 liter beaker
solid rubber stopper (#1) ~800 mL room temperature water

Part I Decompose 3% H2O2 solution with 0.5 M KI solution at ~20°C.

The Decomposition of Hydrogen Peroxide

Advanced Chemistry with Vernier 5

1. Obtain and wear goggles.

2. Prepare the reagents for temperature equilibration.
a. Obtain room temperature water to set up a water bath to completely immerse the test tube.

Use a thermometer or a Temperature Probe to measure the temperature of the bath. Record
this temperature in your data table for Parts I-III; presume that the water bath temperature
remains constant throughout.

b. Measure out 4 mL of 3% H2O2 solution into the test tube. Seal the test tube with the solid
rubber stopper and place the test tube in the water bath.

c. Measure out 2 mL of 0.5 M KI solution in a graduated cylinder. Draw about 1 mL of the
KI solution into a graduated Beral pipet. Invert the pipet and immerse the reservoir end of
the pipet in the water bath.

3. Connect a Gas Pressure Sensor to Channel 1 of the Vernier computer interface. Connect the
interface to the computer using the proper cable.

4. Use the plastic tubing to connect the one-hole rubber stopper to the Gas Pressure Sensor, as
shown in Figure 1. About one-half turn of the fittings will secure the tubing tightly.

5. Start the Logger Pro program on your computer. Open the file “12 Peroxide” from the
Advanced Chemistry with Vernier folder.

6. Prepare to run the reaction and collect pressure data.
d. Remove the test tube from the water bath and remove the solid stopper.
e. Remove the plastic Beral pipet from the water bath and quickly transfer 1 mL of KI

solution into the test tube. Tap or lightly shake the test tube to mix the reagents.
f. Seal the test tube with the one-hole stopper connected to the Gas Pressure Sensor.
g. Place the test tube back in the water bath.

7. Click to begin data collection. Data will be gathered for three minutes. If necessary,
gently hold the test tube so that it stays completely immersed in the water bath.

8. When the data collection is complete, carefully remove the stopper from the test tube to
relieve the pressure. Dispose of the contents of the test tube as directed.

9. Examine the graph of Part I. Select a linear region just beyond the initial flat portion of the
graph that covers one minute of the reaction. Click the Linear Regression button, , to
calculate the best-fit line equation. Record the slope as the initial rate of the reaction in your
data table. Store the results from the first trial by choosing Store Latest Run from the
Experiment menu.

10. Rinse and clean the test tube for the second trial.

Part II Decompose 3% H2O2 solution with 0.25 M KI solution at ~20°C

11. Measure out 4 mL of 3% H2O2 solution into the test tube. Seal the test tube with the solid
rubber stopper and place the test tube in the water bath.

12. Add 1 mL of distilled water to the remaining 1 mL of KI solution in the graduated cylinder.
Swirl the mixture gently to mix the solution.

13. Draw 1 mL of the KI solution into a plastic Beral pipet. Invert the pipet and immerse the
reservoir end of the pipet in the water bath. Allow both the test tube and the Beral pipet to
remain in the water bath for at least two minutes before proceeding.

14. Repeat Steps 6–10 to complete Part II. Remember to store the data.

6 Advanced Chemistry with Vernier

Part III Decompose 1.5% H2O2 solution with 0.5 M KI solution at ~20°C

15. Prepare a 1.5% H2O2 solution by mixing 2 mL of distilled water with 2 mL of 3% H2O2
solution. Transfer the resulting 4 mL of the 1.5% H2O2 solution to the test tube, seal the test
tube with the solid stopper, and place the test tube in the water bath.

16. Rinse and clean the graduated cylinder that you have used for the KI solution. Add a fresh
2 mL of 0.5 M KI solution to the graduated cylinder.

17. Draw 1 mL of the KI solution into a plastic Beral pipet. Invert the pipet and immerse the
reservoir end of the pipet in the water bath. Allow both the test tube and the Beral pipet to
remain in the water bath for at least two minutes before proceeding.

18. Repeat Steps 6–10 to complete Part III, and store the data.

Part IV Decompose 3% H2O2 solution with 0.5 M KI solution at ~30°C

19. Conduct Part IV identically to the procedure in Part I, with one exception: set the water bath
at 30°C.

Part V Decompose 3% H2O2 solution with 0.5 M KI solution at 5-10°C

20. Conduct Part V identically to the procedure in Part I, with one exception: use ice to cool the
water bath to the 5-10 °C range – record the temperature of the bath using a thermometer.

PRE-LAB EXERCISE – to be completed before coming to class
The hydrogen peroxide solution that you are using in this experiment is labeled as a 3% solution,
mass/volume. However, in order to complete the calculations, the concentration must be in
molarity. Calculate the molarity of a 3% mass/volume H2O2 solution (Part I, II, and IV) and a
1.5% mass/volume H2O2 solution (Part III) and record these values in the table below. This table
should be completed in your lab notebook as part of the pre-lab assignment for this experiment.

Part Volume H2O2

before mixing

Volume KI

before mixing

I 4 1 0.50 M
II 4 1 0.25 M
III 4 1 0.50 M
IV 4 1 0.50 M
V 4 1 0.50 M

Show the calculations used in determining the [H2O2] in the carbonless notebook as part of your
pre-lab assignment.

The Decomposition of Hydrogen Peroxide

Advanced Chemistry with Vernier 7

Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text

Type up the following two tables and include them in your formal lab report.

Part Reactants Temperature

Initial rate (kPa/s)

I 4 mL 3.0% H2O2 + 1 mL 0.5 M KI

II 4 mL 3.0% H2O2 + 1 mL 0.25 M KI

III 4 mL 1.5% H2O2 + 1 mL 0.5 M KI

IV 4 mL 3.0% H2O2 + 1 mL 0.5 M KI

V 4 mL 3.0% H2O2 + 1 mL 0.5 M KI


Initial rate

after mixing

after mixing

Rate constant






Show the calculations used to answer questions 1 – 4 below after the data section of your formal
lab report and explain the chemical principles behind each calculation in your discussion section.
You should also explain the chemistry behind your answer to question 5 and define the two
different roles described in 5(a) and 5(b).

1. What is the reaction order with respect to hydrogen peroxide?

2. What is the reaction order with respect to potassium iodide?

8 Advanced Chemistry with Vernier

Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text
Typewritten Text

3. Write the rate law expression for the catalyzed decomposition of hydrogen peroxide and
explain how you determined the order of the reaction in H2O2 and KI.

2. Calculate the rate constant, k, for each part of this experiment. Calculate an average rate
constant at ~room temperature. Do any of the parts of the experiment have rate constants
that are equal or almost equal?

3. Compare the rate of the reaction in part 1 at room temperature with the rate of the reaction in
part 4 at approximately 10oC above room temperature. Approximately how much does rate
increase with a 10oC increase in temperature? Use your values to explain your answer to this

4. Use the Arrhenius equation to determine the activation energy, Ea, for this reaction.
Temperature needs to be expressed in Kelvin when using the Arrhenius equation. This
determination requires analysis of an Arrhenius plot (ln k vs 1/T) as discussed in class and
detailed in your textbook. Use a graphing program to complete the graph and have the program
determine the best straight-line fit to the data (it is not acceptable to do this graph by hand).
From the equation of the line, you can calculate Ea. Show all calculations. Print your graph and
attach it to your lab report when you turn it in…no lab is complete without this plot.

5. The following mechanism has been proposed for this reaction:

H2O2(aq) + I–(aq)→ IO–(aq) + H2O(aq)

H2O2(aq) + IO–(aq) → I–(aq) + H2O(l) + O2(g)

If this mechanism is correct, which step must be the rate-determining step? Please explain your

(a) What is IO-(aq) called in this reaction? (What type of role the ion is playing in the reaction not
its actual ionic name, hypoiodite.)

(b) What is I-(aq) called in this reaction? (What type of role the ion is playing in the reaction not
its actual ionic name, iodide.)

The Decomposition of Hydrogen Peroxide

Advanced Chemistry with Vernier 9

Typewritten Text
Typewritten Text
Note : Ea should be in J/mol or KJ/mol
convert ‘C to ‘Kelvin

Discussion Section
The discussion section should relate the results of this experiment to the impacts of concentration
and temperature to the rate of a chemical reaction. For example your discussion should include
an explanation of why or how changing the concentration of a reactant impacts the rate of a
reaction. You should also include why or how changing the temperature of the solutions impacts
the rate of the chemical reactions observed. Cite your data/results as evidence when you discuss
the impact of concentration (and temperature) changes on the rate of the reaction.

Since any experiment done in lab involves procedures and measurements the discussion section
should also include analysis of errors associated with these. You should include a paragraph or
two describing the errors you may have made in this experiment (any procedural errors) and the
errors inherent to any measurements (measurement errors) made in the experiment. Explain how
each type of error may have influenced the result of the experiment. Since graphical decisions
were crucial in this experiment (and can also contribute significantly to the error) be sure to
explain how you determined the rate of each reaction (why you chose a certain region of the
graph), why it is important to be consistent in this process, and the role this decision plays in the
confidence you have in your results. You are welcome to include a small drawing to aid in your
discussion if it helps to make an idea more clear.

Write a paragraph with a brief conclusion summarizing the results of your experiment and
describing what you learned in the process of doing this experiment. Be sure to include the
results for the quantities you determined (average rate constant at room temperature, the rate law,
and the activation energy) and indicate the largest source of error in your experiment.

10 Advanced Chemistry with Vernier


this data is from problem 14.95 in the 11th edition textbook
T(deg)T(K)1/T (K^-1)ln kk
how to plot in Excel to get the info needed to calculate the activation energy
1. make the table above with your data – you will have to input your rate constants as the k values and your T values in degrees C
– write the formulas as shown in the cells – if you click on the box, the formula will display
– names for cells are ‘column row’ so this cell you are now reading would be alled A12
2. select cells that are light blue and click on the chart button (excel wants data in two columns, left column is x and right column is y)
3. select XY scatter, click next twice to get the the options box
4. fill in chart options with title inluding your name, x axis name as 1/T (K^-1), y axix name as ln(k)
5. click next until this box closes and you see your plot like the one above (exept with your data)
6. left click on a data point to select the data series, then right click on the data point to get the menu
7. choose ‘add trendline’ (type is linear, under options click to add the trendline and R squared correlation to the chart)
8. now use your trendline to calculate the activation energy from the slope of the line
Order a unique copy of this paper
(550 words)

Approximate price: $22