Answer: The amino acid that has a positively charged R group are LYSINE and ARGININE.
Explanation:
AMINO ACIDS are the basic structural units of proteins. Each amino acid contains an amino group ( -NH2) and a carboxyl group (-COOH) in its molecule. The carbon atom of amino acid to which the functional groups are attached is know as the alpha-carbon. In neutral solution, amino acids are mainly in the form of dipolar ions. Amino acids can be prepared through hydrolysis of protein by boiling with dilute hydrochloric acid.
Amino acids can be classified according to the chemical properties of its side chain (R group) at pH 7, these include:
--> Amino acids with POSITIVELY CHARGED R group
--> Amino acids with negatively charged R group
--> Amino acids with neutral polar R group
--> Amino acids with nonpolar aliphatic R group.
Amino acids with POSITIVELY CHARGED R group are those amino acids that has side chains which contain nitrogen and resemble ammonia, which is a base. Their pKa's are high enough that they tend to bind protons, gaining a positive charge in the process. Example include LYSINE and ARGININE.
¿Cómo se divide la tecnología?
de te
Answer:
còmo supòtànté insígídà pàtàtàk
The following compounds all show a single line in their 1H NMR spectra. List them as they would appear in an NMR spectrum, e.g. by decreasing chemical shift with the lowest shift to the right. These compounds would appear in a spectrum in the order.
a. Benzene
b. CH4
c. Cyclohexane
These compounds would appear in a spectrum in the order: _
Answer:
Benzene < Cyclohexane < CH4
Explanation:
The location of a peak in an NMR spectrum is determined by chemical shift. In 1H NMR, a proton that is strongly shielded, It implies a proton that has a high electron density, is exposed to a low magnetic field, which causes the chemical shift to diminish, resulting in a signal towards the right direction of the spectrum.
However, a de-shielded proton with its electron density reduced is exposed to a high magnetic field, which causes and resulted in a chemical shift and causes it to shift to the left of the spectrum.
Electronegativity is one of the factors that influence the electron density because it decreases the proton's electron density attached to it as well as the ones attached to nearby atoms due to the inductive effect. The impact of an electronegative atom diminishes fast as the distance between them grows.
We can utilize the impact of electronegativity to calculate how much chemical shift will take place in each molecule in this question.
The chemical shift for benzene is = 7.26 ppm
Chemical shift for cyclohexane is = 1.44 ppm
Chemical shift for methane = 0.23 ppm
Thus, in decreasing order, the chemical shift with the lowest shift from left to right is:
Benzene < Cyclohexane < CH4
An aqueous solution containing 5.72 g
of lead(II) nitrate is added to an aqueous solution containing 5.85 g
of potassium chloride. The reaction goes to completion, but some was lost in the process of washing and drying the precipitate. The percent yield for the reaction is 81.9%
. How many grams of precipitate is recovered? How many grams of the excess reactant remain? Assume the reaction goes to completion.
Answer:
3.93g are recovered
Explanation:
Pb(NO3)2 reacts with KCl as follows:
Pb(NO3)2 + 2KCl → 2KNO3 + PbCl2
To solve this question we need to find the moles of each reactant in order to find the limiting reactant:
Moles Pb(NO3)2 -Molar mass: 331.2 g/mol-
5.72g * (1mol/331.2g) = 0.01727 moles
Mole KCl -Molar mass: 74.5513g/mol-
5.85g * (1mol/74.5513g) = 0.07847 moles
For a complete reaction of 0.07847 moles of KCl are required:
0.07847 moles KCl * (1mol Pb(NO3)2 / 2mol KCl) = 0.03923 moles Pb(NO3)2
As there are just 0.01727 moles, Pb(NO3)2 is limiting reactant. Assuming 100% of yield:
Moles PbCl2 = Moles Pb(NO3)2
Mass PbCl2 -Molar mass: 278.1g/mol-
0.01727 moles * (278.1g / mol) = 4.80g
As percent yield is 81.9% = 0.819, the mass of PbCl2 recovered was:
4.80g * 0.819 = 3.93g are recovered
Liquid hexane
(CH,(CH), CH) will react with gaseous oxygen (0) to produce gaseous carbon dioxide (CO2) and gaseous water (1,0). Suppose 1.72 g
of hexane is mixed with 8.0 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Be sure your answer has the
correct number of significant digits.
Answer: The mass of [tex]H_2O[/tex] produced is 2.52 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
For hexane:Given mass of hexane = 1.72 g
Molar mass of hexane = 86.18 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of hexane}=\frac{1.72g}{86.18g/mol}=0.020mol[/tex]
For oxygen gas:Given mass of oxygen gas = 8.0 g
Molar mass of oxygen gas= 32 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of water}=\frac{8.0g}{32g/mol}=0.25mol[/tex]
The chemical equation for the combustion of hexane follows:
[tex]2C_6H_{14}+19O_2\rightarrow 12CO_2+14H_2O[/tex]
By stoichiometry of the reaction:
If 2 moles of hexane reacts with 19 moles of oxygen gas
So, 0.020 moles of hexane will react with = [tex]\frac{19}{2}\times 0.020=0.19mol[/tex] of oxygen gas
As the given amount of oxygen gas is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.
Thus, hexane is considered a limiting reagent because it limits the formation of the product.
By the stoichiometry of the reaction:
If 2 moles of hexane produces 14 moles of [tex]H_2O[/tex]
So, 0.020 moles of hexane will produce = [tex]\frac{14}{2}\times 0.020=0.14mol[/tex] of [tex]H_2O[/tex]
We know, molar mass of [tex]H_2O[/tex] = 18 g/mol
Putting values in above equation, we get:
[tex]\text{Mass of }H_2O=(0.14mol\times 18g/mol)=2.52g[/tex]
Hence, the mass of [tex]H_2O[/tex] produced is 2.52 g
For the iron thiocyanate system, what is the value of the equilibrium constant, Kc, if the following are the concentrations of all species present. Provide your answer to three digits after the decimal.
FeSCN2+ 0.501
Fe3+ 0.494
SCN- 0.639
Answer:
Kc = 0.630
Explanation:
The equilibrium of the thiocyanate system occurs as follows:
FeSCN²⁺(aq) ⇄ Fe³⁺(aq) + SCN⁻(aq)
And equilibrium constant, kc, is:
Kc = [SCN⁻] [Fe³⁺] / [FeSCN²⁺]
Replacing with the gven concentrations:
Kc = 0.639M*0.494M / 0.501M
Kc = 0.630Atoms of element X have 12 times the mass of atoms of oxygen, and atoms of oxygen have 16 times the mass of atoms of hydrogen. What is the mass of atoms of element X on a scale on which atoms of hydrogen have a mass of 1?
A. 16/12
B. 12/16
С. 12 x 16
D. 16-12
E. 1216
Answer:
C. 12 × 16
Explanation:
Let mH be the mass of atoms of hydrogen and mO be the mass of atoms of oxygen. The atoms of oxygen have 16 times the mass of atoms of hydrogen. That is,
mO = 16 mH [1]
Let mX be the mass of the atoms of X. Atoms of element X have 12 times the mass of atoms of oxygen. That is,
mX = 12 mO [2]
If we substitute [1] in [2], we get
mX = 12 × 16 mH
If mH is 1, we get,
mX = 12 × 16 × 1
mX = 12 × 16
Identify the Lewis acid and Lewis base from among the reactants in each of the following equations.
Part A
Ag+(aq)+2NH3(aq)⇌Ag(NH3)2+(aq)
a. Ag+ is the Lewis acid and NH3 is the Lewis base.
b. Ag+ is the Lewis base and NH3 is the Lewis acid.
Part B
AlBr3+NH3⇌H3NAlBr3
a. AlBr3 is the Lewis base and NH3 is the Lewis acid.
b. AlBr3 is the Lewis acid and NH3 is the Lewis base.
Part C
Cl−(aq)+AlCl3(aq)⇌AlCl4−(aq)
a. AlCl3 is the Lewis acid and Cl− is the Lewis base.
b. AlCl3 is the Lewis base and Cl− is the Lewis acid.
Answer:
Part A
Ag+ is the Lewis acid and NH3 is the Lewis base.
Part B
AlBr3 is the Lewis acid and NH3 is the Lewis base.
Part C
AlCl3 is the Lewis acid and Cl− is the Lewis base.
Explanation:
A Lewis acid is any specie that accepts a lone pair of electrons. Ag^+, AlBr3 and AlCl3 all accepted lone pairs of electrons according to the three chemical reaction equations shown. Hence, they are Lewis acids.
A Lewis base donates a lone pair of electrons. They include neutral molecules having lone pair of electrons such as NH3 or negative ions such as Cl- .
Discuss the unique properties of carbon as a group 4a element
Answer:
Carbon is dull, have a low density, and are poor conductors of heat.
Explanation:
Carbon is a non-metal, therefore bearing properties of a non-metal element.
You decide to share some sugar sweetened fruit juice with your friend. You divide the fruit equally into two glasses. Then an additional equal volume of water is added to glass 1. Which glass would have the lower molarity?
Answer:
Glass 1
Explanation:
Molarity is measured in moles of substance per liter.
For the sake of calculations, let's say that each glass contains 1 mole of juice and 1 liter after it is divided between the glasses. If you add an equal amount of water to glass 1 ( another liter), you now have:
Glass 1 = 1 mole / 2 liters = 0.5 M
Glass 1 = 1 mole/ 1 liter = 1 M
So glass 1 will have a lower molarity
Cellular respiration results in a
Answer:
A form of energy that can be used by cells.
Explanation:
At 35°C, K = 1.6 × 10^-5 for the reaction
2 NOCl(g) ⇌ 2 NO(g) + Cl2(g)
Calculate the concentrations of all species at equilibrium for each of the following original mixtures.
a. 2.0 mol pure NOCl in a 2.0 L flask
b. 2.0 mol NOCl and 1.0 mol Cl2 in a 1.0 L flask
Answer:
a) [NOCl] = 0.968 M
[NO] = 0.032M
[Cl²] = 0.016M
b) [NOCl] = 1.992M
[NO] = 0.008 M
[Cl2] = 1.004 M
Explanation:
Step 1: Data given
Temperature = 35°C = 308K
K = 1.6 × 10^-5
Step 2: The reaction
2 NOCl(g) ⇌ 2 NO(g) + Cl2(g)
For 2 moles NOCl we'll have 2 moles NO and 1 mol Cl2
Step 3
a. 2.0 mol pure NOCl in a 2.0 L flask
Concentration at the start:
Concentration = mol / volume
[NOCl] = mol / volume
[NOCl] = 2.0 / 2.0 L
[NOCl] = 1.0 M
[NO] = 0 M
[Cl] = 0M
Concentration at the equillibrium
[NOCl] = 1.0M - 2x
[NO] = 2x
[Cl2]= x
K = [Cl2][NO]² / [NOCl]² = 1.6*10^-5
1.6*10^-5 = ((2x)² * x) / (1.0-2x)²
x = 0.016
[NOCl] = 1.0 - 2*0.016 = 0.968 M
[NO] = 2*0.016 = 0.032M
[Cl²] = 0.016M
b. 2.0 mol NOCl and 1.0 mol Cl2 in a 1.0 L flask
Concentration at the equillibrium
[NOCl] = 2.0 mol / 1.0 L = 2.0 M
[NO] = 0 M
[Cl2]= 1.0 mol / 1.0 L = 1.0 M
Concentration at the equillibrium
[NOCl] = 2.0M - 2x
[NO] = 2x
[Cl2]= 1.0 + x
K = [Cl2][NO]² / [NOCl]² = 1.6*10^-5
1.6 *10^-5 = (2x)²*(1.0+x) / ((2.0-2x)²)
1.6 *10^-5= (2x)² * 1 )/2.0²
1.6 *10^-5= 4x² / 4 = x²
x = [tex]\sqrt{1.6 *10^-5}[/tex] = 4.0*10^-3
[NOCl] = 2.0 - 2*0.004 = 1.992M
[NO] = 2*0.004 = 0.008 M
[Cl2] = 1+ 0.004M = 1.004 M
Between energy and life which one comes first answer with scientific reason
Explanation:
While the sun is an excellent source of energy, not all forms of life can utilize the sun's energy directly. This lesson describes how plants transform the sun's energy into potential energy stored in sugar, how living organisms utilize energy in sugar to perform work, and how the relationship between photosynthesis and cellular respiration is necessary for life.
Create an account
Perform the following
mathematical operation, and
report the answer to the correct
number of significant figures.
7.125 x 8.00 = [?]
Answer ?
Classify each compound as ionic or molecular.
a. ZnCl2
b. MgS
c. CH4
Answer:
ZnCl2=ionic
MgS=ionic
CH4=molecular
Explanation:
ZnCl₂=ionic, MgS=ionic and CH₄=molecular compounds.
Thus, Ions with opposing charges that are kept together by electrostatic forces make up ionic compounds. Typically, a metal and a nonmetal combine to make them.
Atoms share electrons through covalent bonds to form molecular compounds.
When atoms of various elements share electrons through covalent bonds, molecules are created, also known as covalent compounds. These compounds consist of molecules made up of joined atoms, and the shared electrons strengthen the bonds between the atoms.
Thus, ZnCl₂=ionic, MgS=ionic and CH₄=molecular compounds.
Learn more about Electrons, refer to the link:
https://brainly.com/question/12001116
#SPJ3
g Suppose you are titrating vinegar, which is an acetic acid solution of unknown concentration, with a sodium hydroxide solution according to the equation H C 2 H 3 O 2 + N a O H ⟶ H 2 O + N a C 2 H 3 O 2 If you require 30.01 mL of 0.1798 M N a O H solution to titrate 10.0 mL of H C 2 H 3 O 2 solution, what is the molar concentration of acetic acid in the vinegar? Type answer:
Answer: The molar concentration of acetic acid in the vinegar is 0.539 M.
Explanation:
The formula used is:
[tex]M_1V_1=M_2V_2[/tex]
where,
[tex]M_1[/tex] and [tex]V_1[/tex] are the concentration and volume of base.
[tex]M_2[/tex] and [tex]V_2[/tex] are the concentration and volume of an acid.
Given:
Molar concentration of NaOH = 0.1798 M
Volume of NaOH = 30.01 mL
Volume of acetic acid = 10.0 mL
Now putting all the given values in the above formula, we get:
[tex]M_1V_1=M_2V_2\\\\0.1798M\times 30.01mL=M_2\times 10.0mL\\\\M_2=0.539M[/tex]
Thu, the molar concentration of acetic acid in the vinegar is 0.539 M.
What is the difference between a physical change and a chemical change. Give an example of each.
Answer:
A physical change is a change in form.
A Chemical change is a change in materials.
Explanation:
Example of a physical change would be an ice cube meting.
Example of a chemical change would be mixing food coloring into a cup of water.
Which of the following is an oxidation reduction reaction
Oxidation is lost of electrons. Reduced is gain of electrons. you can also remember them as OIL RIG.
help please and thank you!
Answer:
a) N2(g) + H20 (aq) --> HNO3 (aq) + NO (g)b) 40 NO2(g) + H20(aq) = 20 HNO3(aq) + 20 NO(g)Explanation:
A series of measurements in the lab led to an experimental result of 32.9 mL, with a calculated standard deviation of 0.3 mL. What is the standard way to report this result?
Answer: The standard way to report this result is [tex]32.9\pm 0.3 mL[/tex]
Explanation:
The standard method of representing a result is:
[tex]\text{Calculated value }\pm \text{ Standard deviation}[/tex]
The reporting of a result is done in correct significant figures.
We are given:
Calculated value = 32.9 mL
Standard deviation = 0.3 mL
Rule of significant figures applied when numbers are added or subtracted:
The number having less number of significant figures after the decimal point will determine the number of significant figures in the final answer.
Number of significant figures after the decimal point = 1
Hence, the standard way to report this result is [tex]32.9\pm 0.3 mL[/tex]
What is the observation of heating of iodine crystals
Answer:
On heating, the van der Waals dispersion forces existing then will easily break as it has a low boiling point and sublimates into gas. On heating iodine in the test tube, iodine evolves as violet fuming gas.
Explanation:
The compound magnesium nitrate has the formula Mg(NO3)2.
What is the relative formula mass of magnesium nitrate?
Explanation:
Answer
Open in answr app
Correct option is
C
148
1 atom of Mg=1x24=24
2 atom of N=2x14=28
6 atom of O=6x16=96
Total mass=148
Which best expresses the uncertainty of the measurement 32.23 cm?
A.) ±0.05 cm
B.) 0.1 cm
C.) 1%
D.) ±0.01 cm?
Answer:
D.) ±0.01 cm?
Explanation:
Since 32.23 cm has two decimal places, the uncertainty is taken as one-half the last decimal pace.
The last decimal place is 0.03. Half of this is 0.03 cm/2 = 0.015 cm.
Since we cannot go below two decimal places, we ignore the 5 in 0.015 cm.
So, we have our uncertainty as 0.01 cm.
So, the best expression of the uncertainty in the measurement 32.23 cm is ± 0.01 cm.
So, the answer is D. which is ± 0.01 cm.
d=ut+5 make u the subject
Explanation:
d=ut+5
d-5=ut
d-5/t=u
!!!!!!!
A buffer solution contains 0.298 M ammonium chloride and 0.478 M ammonia. If 0.0560 moles of hydroiodic acid are added to 225 mL of this buffer, what is the pH of the resulting solution?
Answer:
pH = 8.87
Explanation:
Hydroiodic acid, HI, is a strong acid that reacts with ammonia, NH3, to produce ammonium ion, NH⁴⁺. That means the moles of HI added = moles of NH3 consumed and moles of NH4⁺ produced.
Initial moles NH₄⁺:
0.225L * (0.298mol/L) = 0.06705 moles
Initial moles NH3:
0.225L * (0.478mol/L) = 0.10755 moles
After the reaction the moles are:
0.10755moles NH3 - 0.0560moles = 0.05155 moles NH3
0.06705moles NH4+ + 0.0560moles = 0.12305 moles NH4+
Using H-H equation for weak bases:
pOH = pKb + log ([NH4+] / [NH3])
pKb for ammonia is 4.75, [NH4+] could be the moles of NH4+ = 0.12305mol,
[NH3] = 0.05155moles
Replacing:
pOH = 4.75 + log (0.12305mol / 0.05155moles)
pOH = 5.13
pH = 14-pOH
pH = 8.87What do molarity and molality have in common?
Answer:
Both molarity and molality involves number of moles of solute
Explanation:
Molarity is obtained by dividing the number of moles of solute by the volume of solution in liters. Note that a solution is formed when a solute is dissolved in a given volume of solvent.
Molality, of a solution is obtained by dividing the number of moles of a solute by the number of kilogrammes of solvent.
In both cases, the number of moles of solute is involved. Hence, the number of moles of solute present is common to both molarity and molality calculation.
Place the following in order of increasing molar entropy at 298 K.
a. C3H8 < SO < CO2
b. CO2 < C3H8 < SO
c. C3H8 < CO2 < SO
d. SO < CO2 < C3H8
e. CO2 < SO < C3H8
Answer:
SO < CO2 < C3H8
Explanation:
Entropy refers to the degree of disorderliness of a system. The standard molar entropy of a substance refers to the entropy of 1 mole of the substance vunder standard conditions.
The molar entropy depends on the number of microstates in the system which in turn depends on the number of atoms in the molecule.
C3H8 has 11 atoms and hence the highest number of microstates followed by CO2 having three atoms and least of all SO having only two atoms.
No tires P ni basura al suelo
Answer:
no halbo ingles
Explanation:
For this task, you will consider the information you have researched so far, conduct further research, create a thesis, and write a one-page research paper based on your research and thesis. Your research and thesis should address the following prompt: How should Florida address its growing energy demands, and what energy sources should the state focus on in the future? Consider the energy options available in Florida, the pros and cons of various energy sources, as well as concepts such as energy conservation.
In the next steps, you will conduct further research, form a thesis, and write a one-page research paper based on your findings and opinions.
a. Select a topic. Before creating your report, understand the purpose, process, and goals of a research assignment.
The first step in writing a research paper is to select a topic; in this assignment your topic should focus on issues related to energy production and consumption in Florida.
Begin brainstorming ideas by thinking about your prior knowledge of the topic.
Try engaging in preliminary research to help select a relevant, interesting topic.
b. Choose a thesis statement. Begin thinking about the stance or viewpoint that your writing will take. Once you have a general idea of your opinion, develop a thesis statement, or the main idea of an essay that includes the topic and the viewpoint.
Make sure that the thesis is relevant to the topic and assignment.
Keep in mind that as you continue researching and begin writing, your thesis may change slightly from your original idea.
Check with your teacher to make sure that the topic you chose is appropriate and feasible.
c. Gather sources. Next, begin gathering and organizing additional sources to build your argument. It is important to understand the purpose of your research. Evaluate each source, and consider these questions:
Who authored the document?
What is the purpose of the document?
When was the document written?
How will this document help your argument?
d. Develop your position. Now that you have analyzed sources to use as evidence, revisit the essay topic. Then develop your report with these factors in mind:
Create an outline to help organize the structure of your report.
Your thesis should be well-supported by your research.
Match the evidence in your sources to the points in your report.
Articulate any solutions you may think are relevant to deal with the energy issues in Florida.
e. Write your first draft. Write a one-page research paper on your selected topic. As you write your paper, use quotations from and summaries of your sources to support your argument.
To avoid plagiarism, make sure to cite your sources properly with in-text citations and a works cited page.
f. Proofread and Revise. When you are finished writing your first draft, reread your essay to check for all of the points above, and then proofread and revise to be sure your work doesn’t contain errors in grammar, spelling, logic, or cohesion. Finally, develop a final draft that is polished and ready to be turned in. Nice work!
Answer:
What kind of chemical reaction occurs when fossil fuels and biomass are burned? What is produced in addition to energy?
What is acid rain? Which fossil fuel causes acid rain? What are the chemical reactions that produce the acid?
Difference Between Biomass and Fossil Fuels
In terms of environmental impact, what’s the difference between natural gas, coal, and biomass? Consider both carbon dioxide (CO2) emissions and acid rain.
What’s the difference between nonrenewable and renewable energy sources? Is biomass a renewable energy source?
What’s a new discovery that makes it easier to use biomass as an energy source?
Comparing Biomass with Other Renewable Energy Sources
What are the pros and cons of several renewable energy sources? Renewable energy sources include biomass, wind power, hydropower, solar power, and geothermal power.
Making Recommendations for Energy Choices
Which renewable energy sources should be developed in your area, and why? Consider abundance of the energy source, ease of setup in your area, and cost.
Review the seven questions. Write a few sentences summarizing what you already know about these topics.
Explanation:
table salt is 42.7% sodium how many grams of salt contain 76 g of sodium
Answer:
Số gam muối ăn cần là 76:42,7%=177,986 g
Explanation:
draw the structure of two acyclic compounds with 3 or more carbons which exhibits one singlet in the 1H-NMR spectrum
Answer:
attached below
Explanation:
Structure of two acyclic compounds with 3 or more carbons that exhibits one singlet in 1H-NMR spectrum
a) Acetone CH₃COCH₃
Attached below is the structure
b) But-2-yne (CH₃C)₂
Attached below is the structure
