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.

"; Chemistry Assignment-Atomic Structure, Chemical Bonding, Lewis Structure, And 3D Molecular Shape - Chem Homework Help
Chemistry Assignment-Atomic Structure, Chemical Bonding, Lewis Structure, and 3D Molecular Shape

Name(s):_______________________________ CHM 1020 Lab | Week 4

Week 4 Assignment a, b, and c

Atomic Structure, Chemical Bonding, Lewis Structure, and 3D Molecular Shape

Objectives

In this lab, you will apply valence bond theory to draw appropriate Lewis structures, use electronegativity differences to classify bonds as ionic, polar covalent, or nonpolar covalent, and apply valence shell electron pair repulsion theory (VSEPR) to predict molecular geometry. We will also use molecular kits to create ball and stick models of molecules of interest to you.

Theory

Atoms of certain species tend to bond together. An atom is more stable if its valence shell (electrons in its outermost energy level) is similar to that of a Noble Gas (typically eight electrons), and this number is most often achieved when atoms combine. Notice that atoms of elements in the same group on the periodic table tend to have the same number of valence electrons; for example, halogens, Group 7A elements (Figure 1), have seven valence electrons.

Figure 1: Dot Diagrams

For most elements, a full outer energy level has eight electrons, an octet. The elements in group 8A have a full outer energy level. Helium (He), in period 1, is an exception, requiring only two electrons. Because group 8A elements’ atoms already have a full outer energy level, those elements tend to be nonreactive—they rarely combine with other atoms to form compounds. Atoms can fill their outer energy level by transferring or sharing electrons to form either ionic or covalent compounds.

Figure 2: Two Bonding Types

Whether two given atoms tend to bond ionically or covalently is determined by the difference in their electronegativity. Electronegativity is a dimensionless number that is a measure of an atom’s attraction for bonding valence electrons. Electronegativities show periodic trends on a periodic table.

Figure 3: Table of Electronegativities

Excluding the noble gases, the most electronegative element is fluorine, which is assigned a value of 4.0. The other elements’ values are calculated on the basis of that of fluorine. Across each period, electronegativities tend to increase. The nonmetal families of nitrogen, oxygen, and fluorine have the highest values. Due to their atoms’ small radii, the positive nuclei exert a greater attraction for bonding electrons. The alkali metals and alkaline earth metals (the groups on the left side of the periodic table) have the lowest electronegativities because their atoms have the largest radii. Cesium (and francium – not shown in Figure 3), with the largest radii, have the lowest electronegativity, at 0.7.

Lewis Dot Structures

A Lewis dot structure is one way to represent the arrangement of valence electrons in a molecule (Figure 1). In Lewis structures, an element symbol is surrounded by a specific number of dots representing valence electrons. Most atoms obey the octet rule; they need eight valence electrons to fill their outer shell. (Exceptions include hydrogen and helium, which need only two. Also, boron and beryllium may form compounds with fewer than eight, and elements in periods 3–6 may use more than eight.)

To fill their outer shells, elements can form covalent bonds by sharing electrons. To show those bonds, Lewis structures are often used. Covalent compounds may have single, double, or triple bonds between atoms. These bonds are represented in a Lewis structure with dashes between the chemical symbols of the bonded elements. The number of dashes corresponds to the number of bonds. Lewis structures also indicate the lone pairs of electrons on different atoms. Use the guide below if it helps in drawing Lewis Structures.

Guide for Drawing Lewis Structures

1. Determine the total number of valence electrons for the molecule. To do this, look at which group the element is in on the periodic table.

· If you have an ion, add or subtract electrons as necessary to the above total.

2. Draw initial connectivity by placing the least electronegative atom (not considering hydrogen) in the molecule at the center. Next, draw individual lines (bonds) to connect atoms (each line contains 2 electrons) to complete the octets around all the atoms bonded to the central atom.

3. Place leftover electrons on the central atom, even if doing so results in more than an octet of electrons around the atom.

4. If there are not enough electrons to give the central atom an octet, try multiple bonds (double covalent or even triple covalent).

Part a: Lewis Structures

Procedure

1. Select two compounds in Group 1, two compounds in Group 2, and two compounds in Group 3 to use in experiments 1, 2, and 3. You will focus on these six compounds in all three “experiments” (or activities) in today’s lab.

Group 1Group 2Group 3
1. CH4

2. PCl3

3. PCl5

4. SF6

1. CO2

2. NH3

3. H2O

4. SF4

1. O2

2. HCN

3. CH3OH

4. H2CO

2. Copy each chemical formula chosen into the spaces provided in the first column of Data Table 1.

3. Use the Guidelines for Drawing Lewis Structures (page 3) to complete the Data Table 1.

4. Exchange Data Table 1 with another member of your group. Look over their responses for experiment 1. For each response, ensure that your classmate:

a. copied the chemical formula correctly.

b. drew dot diagrams that match those provided in Figure 1.

c. accounted for the correct number of each type of atom.

d. accounted for the correct number of electrons for each type of atom.

e. selected the appropriate central atom.

f. drew a Lewis structure that includes the appropriate number of electrons.

5. Return Data Table 1 to its original owner and discuss any errors you found. Ask your teacher for assistance if you and your classmate disagree about what correct responses should be.

6. As needed, make corrections to your responses.

Data Table 1 (Group 1):

Chemical Formula:Central Atom:
Dot Diagrams:Valence Electrons:
Lewis Structure:
Chemical Formula:Central Atom:
Dot Diagrams:Valence Electrons:
Lewis Structure:

Data Table 1 (Group 2):

Chemical Formula:Central Atom:
Dot Diagrams:Valence Electrons:
Lewis Structure:
Chemical Formula:Central Atom:
Dot Diagrams:Valence Electrons:
Lewis Structure:

Data Table 1 (Group 3):

Chemical Formula:Central Atom:
Dot Diagrams:Valence Electrons:
Lewis Structure:
Chemical Formula:Central Atom:
Dot Diagrams:Valence Electrons:
Lewis Structure:

Part b: Molecular Geometry

In this experiment you will apply valence shell electron pair repulsion theory (VSEPR) to predict molecular geometry. Afterwards, you will construct three-dimensional molecular models, using small, pronged atoms and flexible bonds (included in the kits). lastly, you will sketch a three-dimensional model of chemical structure using dashed lines and wedges for at least one of your molecules.

Procedure

1. For each compound in Experiment 1, determine how many electron domains are present on the central atom (use the Lewis structures from Experiment 1). Record the number of electron domains in the appropriate column in Data Table 2 (below).

2. Next, again using your previous Lewis Structure, determine how many electron domains on the central atoms are lone pairs. Record your answer in the appropriate column of Data Table 2 (below).

3. Once you have determined the number of electron domains and number of lone pairs, use the reference table below (Figure 4) to determine the appropriate molecular geometry (name and bond angles). Record your answer in Data Table 2 (below).

Figure 4: Molecular Geometries

Data Table 2:

Chemical Formula# of Electron DomainsNumber of lone pairs on Central AtomMolecular geometry

Part c: Bonding and Polarity

In this experiment you will calculate electronegativity differences to determine bond type. Then, you will calculate molecular polarity and identify dipole moment.

Background

Although chemical bonds are characterized as covalent or ionic, they are rarely fully one type or the other. Few molecules are fully covalent, sharing valence electrons equally, and few are fully ionic, with a complete transfer of valence electrons. Instead, bonds are typically described on the basis of the character exhibited most; for example, the bond between a metal and a nonmetal has more ionic character than covalent and so is referred to as an ionic bond. The bond between two nonmetals is typically considered covalent. In a nonpolar covalent bond, electrons are shared equally. In a covalent bond with a certain amount of ionic character, the electrons are not really equally shared. The atom with the greater electronegativity attracts the electrons more strongly. This unequal sharing creates poles of charge, and thus these bonds are termed polar covalent bonds.

Because bonds usually fall somewhere between truly covalent and truly ionic, chemists sometimes use the terms percent ionic and percent covalent to describe the bonding between atoms. One way to calculate these percentages is to first determine the difference between the electronegativities of two atoms. If the electronegativity difference is greater than 1.9, the bond is considered more ionic than covalent and is characterized as ionic. If the difference is 1.9 or less, the bond is said to be covalent. An electronegativity difference between 1.9 and 0.5 indicates a polar covalent bond, while any bond polarity lower than 0.5 indicates a nonpolar covalent bond.

Figure 5: Approximate ranges of bond polarity for Ionic, Polar Covalent, and Nonpolar Covalent bonds

Bond Polarity

The terms nonpolar and polar are useful descriptors for covalent bonds. A nonpolar covalent bond has no region (pole) of positive or negative charge. An example of this type of bond is the bond between two identical atoms, as in H2. Because each hydrogen atom has one available electron, the electronegativity difference (|2.1 – 2.1|) equals 0. The two atoms exert the same amount of attraction on the electrons (H··H).

In a polar covalent bond, one atom attracts the bonding electrons more strongly than the other does. The tendency of the electrons to be closer to one atom than the other creates the poles of charge. The atom with the stronger attraction has a partial negative charge, and the other has a partial positive charge. Consider hydrochloric acid, HCl. The electronegativity difference between chlorine and hydrogen is 0.9 (|3.0 – 2.1| = 0.9). Chlorine is more electronegative and therefore pulls the bonding electron pair more closely, giving the hydrogen a partial positive charge (delta plus, δ+) and the chlorine a partial negative charge (delta minus, δ–).

Figure 6: Hydrochloric acid, HCl, showing partial charges

Unequal sharing of electrons can be represented by a vector indicating bond polarity. To show bond polarity, draw a vector from the positively charged atom to the negatively charged atom. Create a plus sign using a vertical line near the less electronegative atom. The vector arrow points toward the more electronegative atom.

Figure 7: Hydrochloric acid, HCl, showing bond polarity

Molecular Polarity

Molecular polarity is similar to bond polarity. A polar molecule has regions of partial positive and negative charge, oriented in an electric field. The orientation, called a dipole moment, is caused by asymmetric distribution of charges within the molecule. The molecular dipole moment is shown as a vector beside the molecule. Once again, the vector arrow points toward the more electronegative atom.

Figure 8: Hydrochloric acid, HCl, showing molecular dipole moment

Molecules that demonstrate a dipole moment are characterized as polar. Molecules of hydrochloric acid are polar because the bond polarity is unbalanced.

Not all molecules that contain polar covalent bonds are themselves polar. If bond polarity is balanced, partial positive and negative charges are distributed symmetrically. If positive and negative charges are distributed symmetrically, the molecule does not orient itself in an electric field and does not demonstrate a dipole moment. Molecules that do not demonstrate a dipole moment are characterized as nonpolar.

Beryllium chloride is an example of a nonpolar molecule that contains polar covalent bonds. Each Be–Cl bond is polar covalent with an electronegativity difference of 1.5 (|1.5 – 3.0| = 1.5). However, molecular geometry of beryllium chloride (linear) results in symmetrical bonds and a nonpolar molecule. Beryllium chloride does not have a dipole moment because the opposing bond polarities cancel each other.

Figure 9: Beryllium chloride, BeCl, showing bond polarity

It is also possible to arrange polar covalent bonds symmetrically in three-dimensional space. For example, in carbon tetrachloride, each C–Cl bond is a polar covalent one. The electronegativity difference is 0.5 (|2.5 – 3.0| = 0.5). The molecular geometry of carbon tetrachloride (tetrahedral) results in three-dimensional symmetry and a nonpolar molecule. Carbon tetrachloride does not have a dipole moment because the opposing bond polarities cancel each other.

Figure 10: Carbon tetrachloride, CCl4, showing cancelation of polar bonds

Polar molecules are the result of unbalanced bond polarity; consequently, all polar molecules are asymmetrical in some way. If one chlorine atom in carbon tetrachloride (CCl4) is replaced with a hydrogen atom, the molecule becomes chloroform (CHCl3). The tetrahedral molecule is no longer symmetric; it is asymmetric and polar. This molecule has a region of partial positive charge near the hydrogen atom and a region of negative charge near the chlorine atoms. The configuration results in a molecular dipole moment shown by the large vector on the far right.

Figure 11: Chloroform, CHCl3, a polar molecule

The presence of lone pairs of electrons contributes to the polarity of a molecule. Lone pairs are regions of partial negative charge; however, not all molecules that contain lone pairs are polar. The combination of molecular geometry and multiple lone pairs may result in a symmetric, nonpolar molecule.

Procedure

1. Complete Data Table 3 (below), using the Periodic Table of the Electronegativities (Figure 3) and the Bonding Scale (Figure 5) to determine the type of bond each set of atoms would exhibit if they formed a bond. After copying down the Chemical formula, next, list the unique bonds between pairs of atoms.

2. In column 3, determine the electronegativity differences between each pair of bonded atoms identified.

3. In column 4, write down the classification of each identified bond according to the electronegativity difference from column 3, and figure 5.

4. In column 5, determine if the molecule is polar or nonpolar overall (see the discussion over the last three pages [pgs. 12 – 14] for a refresher of molecular polarity).

Data Table 3:

Chemical FormulaUnique Bonds between atomsElectronegativity difference for each bond (figure 3) Bond classification (figure 5)Is Molecular Polar/Nonpolar

Page 2 of 2

Order a unique copy of this paper
(550 words)

Approximate price: $22