Answer:D all of these
Explanation:
I just did it and that’s the correct answer
5) Low iron concentration (as low as 0.02 nM) in the open ocean limits phytoplankton growth. Preconcentration is required to determine such low concentrations. Trace Fe3 from a large volume of seawater is concentrated onto a 1.2 mL chelating resin column, the column is then rinsed with 30 mL of high purity water and eluted with 10 mL of 1.5 M high purity HNO3. a.) For each sample, seawater is passed through the column of 17 h at 10 mL./min. How much is the concentration of Fe3 in the 10 mL of HNO3 eluate increased by this preconcentration procedure
Answer:
Check the explanation
Explanation:
Sample volume V= 10 mL/min x 17 h x 60 min/h / 1000 mL/L = 10.2 L
The concentration is increased
10200 mL (sample volum) / 10 mL (eluted sample) = 1020 times.
57x10-9 M / 1020 = 5.6x10-12 M
1.5 M HNO3 will contain ≤ 2ppm x (1.5M/15.7M ) ≤ 0.190 ppm ≤ 190 ppb
Ignoring this is reagent impurity and calculating for sea water
≤ 190 ppb /1020 = 0.186 ppb = 0.186 x 10-9g/mL = 0.186 x 10-6g/L =
0.186 x 10-6g/L / 56 g/mol = 0.003 x10-6 M = 3 nM
When a chemical reaction occurs blank happens
Answer:
In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
Explanation:
PLEASE help! BRAINLIEST to correct answer!
Answer:
C
Explanation:
Answer:
I think its q
Explanation:
h is the Planck constant, c the speed of light
cis-1-Bromo-4-tert-butylcyclohexane and trans-1-bromo-4-tert-butylcyclohexane both react with sodium ethoxide in ethanol to form 4-tert-butylcyclohexene. Explain why the cis isomer reacts much more rapidly than the trans isomer. Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.
Answer:
See explanation below
Explanation:
In order to explain this, is neccesary to draw both confomers, the cis and trans, but in the chair conformation, because in that way we can see much better the bonds and the reason of why the cis reacts faster than trans.
As you can see in picture attached, the more stable conformer is the one where the H and Br are in the axial position, and the tert butyl group in equatorial position. In these positions, the cis isomer can undergo an E2 reaction, and the ethoxide would have no problem to substract the hydrogen atom from the molecule to eliminate the Bromide. This is because the t-butyl group in equatorial position, is not exerting steric hindrance, therefore is faster.
In the case of the trans, the t-butyl group is in the axial position as well as the hydrogen and bromide, therefore, when the E2 reaction undergoes, the hydrogen is substracted by ethoxide, but it will be slow because the t.butyl group exerts steric hindrance in the axial positions, therefore, the hydrogen will be substracted slower than in the cis position. This is the main reason for the cis to be faster.
As for the second part of the question, which will be the answer of the whole question, see picture attached 2 for the whole sentence, and the match of the words is the following:
1. Axial
2. More
3. Blank (No word there)
4. less
5. Blank
6. Cis
7. Trans
8. Cis
What is the molarity of sodium hydroxide solution made by combining 2.0 L of 0.60
NaOH With 495 mL 3.0 M NaOH? Assume the volumes of the two solutions to be additive___M
Answer:
[tex]M=1.1M[/tex]
Explanation:
Hello,
In this case, since we are mixing two NaOH solutions, the first step is to compute the total moles once the mixing is done, by using the volumes and concentrations of each solutions and subsequently adding them:
[tex]n_T=2.0L*0.60\frac{mol}{L}+495mL*\frac{1L}{1000mL}*3.0\frac{mol}{L}= 2.7molNaOH[/tex]
Next, we compute the total volume by adding the volume of each solution:
[tex]V_T=2.0L+495mL*\frac{1L}{1000mL}= 2.495L[/tex]
Finally, we compute the molarity of the resulting solution by the division between the total moles and the total volume:
[tex]M=\frac{2.7mol}{2.495L}\\ \\M=1.1M[/tex]
Best regards.
A student wants to examine a substance without changing its identity. Which of the following properties should the student examine?
Answer:
A. Ductility, because it can be observed by altering the shape of the substance
Explanation:
Changing the shape of a substance does not change its identity.
What is the ideal pH level for your blood?
HELP PLEASE ILL GIVE 25 pointsWhich of the following practices could help reduce erosion of water banks? a. buffer strips b. natural fertilizers and pesticides c. decrease in fossil fuel emissions d. all of the above Please select the best answer from the choices provided A B C D
Answer:
A. Buffer strips
Explanation:
The practice that could help reduce erosion of water banks is buffer strips.
What is erosion?Erosion is the action of surface processes that removes soil, rock or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited.
One of the practices that could be used to reduce the effect of erosion is buffer strips.
What buffer strips do is slow and filter storm runoff while helping to hold soil in place.
Learn more on buffer strips here; https://brainly.com/question/26872640
In a titration, 100 mL of 0.026 M HCl (aq) is neutralized by 13 mL of KOH(aq). Calculate the molarity of KOH (aq).
Answer:
0.2M
Explanation:
Step 1:
Data obtained from the question.
Volume of acid (Va) = 100mL
Molarity of the acid (Ma) = 0.026 M
Volume of base (Vb) = 13mL
Molarity of the base (Mb) =..?
Step 2:
The balanced equation for the reaction. This is given below:
HCl + KOH —> KCl + H2O
From the balanced equation above,
The mole ratio of the acid (nA) = 1
The mole ratio of the base (nB) = 1
Step 3:
Determination of the molarity of the base, KOH. This can be obtained as follow:
MaVa/MbVb = nA/nB
0.026 x100 / Mb x 13 = 1
Cross multiply to express in linear form
Mb x 13 = 0.026 x 100
Divide both side by 13
Mb = 0.026 x 100 / 13
Mb = 0.2M
Therefore, the molarity of the base, KOH is 0.2M
Answer:
0.2M
Explanation:
KOH(aq) + HCl(aq) ⇒ KCl(aq) + H2O(l)
We express the moles of analyte (HCl) and titrant based (KOH) on their molar concentration:
M1 * V1 = M2 * V2
The molarity of the solution is calculated with the following equation:
M2 = V1 x M1 / V2
Where:
V2 = valued sample volume
V1 = volume of titrant consumed (measured with the burette)
M1 = concentration of titrant solution
M2 = concentration of sample
M2 = 100mL * 0.026M / 13mL = 0.2M
If the mole fraction of Na2S in an aqueous solution is 0.125,
what is the weight/weight %
(percent by mass) of Na2S?
Answer:
Explanation:
Hello,
In this case the molar fraction of sodium sulfide, whose molar mass is 78 g/mol, is 0.125, it means we have 0.125 moles of sodium sulfide per mole of solution, so we compute the mass of sodium sulfide and water as shown below:
[tex]m_{Na_2S}=0.125mol*\frac{78gNa_2S}{1molNa_2S} =9.75 gNa_2S\\\\m_{H_2O}=(1-0.125)molH_2O*\frac{18gH_2O}{1molH_2O} =15.75gH_2O[/tex]
Then, we can calculate the eight/weight % as follows:
[tex]w/w \%=\frac{9.75g}{9.75g+15.75g}*100\% \\\\w/w \%=38\%[/tex]
Regards.
Answer: 38
Explanation:
pls I need help with these ques. help plsssssssssssssss
Answer:
q1..no.2 and 4 are aromatic
What is a noble gas electron configuration of bismuth?
Answer:
It is [Xe] 4f14 5d10 6s2 6p3 and its atomic number is 83
40 POINTS!
Answer correctly for full 40!
Answer:
A. cell wall
Explanation:
A cell wall is rigid and is the outermost layer. It also shapes the cell.
A cell membrane is the inner portion of the cell wall and very flexible, not rigid.
The nucleus is not a membrane, it is the center of cell containing genetic information.
The mitochondria is within the cell and it known as the "powerhouse" of the cell.
- Hope that helps! Please let me know if you need further explanation.
Answer:
Jesus loves you
) A concentration cell is based on the aqueous reaction
Cu2+(1.00 M) Cu2+(0.0100 M)
The cell consists of copper electrodes dipping into solutions of Cu2+ ions. The anions present are sulfate ions. Draw a neat diagram to represent this cell, showing and labeling all necessary components including: anode, cathode, electron flow, cation flow and anion flow.
Answer:
Kindly check the attachment for the diagram representing the cell and showing all necessary components including: anode, cathode, electron flow, cation flow and anion flow.
Explanation:
So, the reaction in the concentration cell is given below as;
Cu2+(1.00 M) → Cu2+(0.0100 M).--(1).
The anode = Cu2+(0.0100 M) because it has lesser Concentration, thus, lesser potential value.
Cathode = Cu2+(1.00 M) because it has higher Concentration, hence higher potential value.
It must be noted that in the digaram depicting the Reaction, the electrons moves from the anode part of the cell to the cathode part of the cell and this is done through an external circuit. The following are the things that happens at each electrode;
At the Anode: in here is where oxidation occurs and Cu^2+ is released into the solution.
At the cathode: in here is where the reduction occur and the Cu^2+ moves in the direction to where the Cu electrode is, thus, causing the deposition of Cu.
Nitrogen gas has a volume of 10.00L when under a
pressure of 1000. mmHg. If the temperature stays constant calculate
the new volume if the pressure drops to 500.mmHg.
Answer:
THE NEW VOLUME OF THE NITROGEN GAS AT 500 mmHg IS 20 L
Explanation:
We will solve the question by using the Boyle's law equation;
P1V1 = P2V2
Write out the values of the variables involved in the question
P1 = 1000 mmHg
V1 = 10 L
P2 = 500 mmHg
V2 = ?
Substitute the values into the equation, we have;
V2 = PIV1 / P2
V2 = 1000 * 10 / 500
V2 = 10000 /500
V2 = 20 L
The new volume of the nitrogen gas at a pressure of 500 mmHg is 20 L.
A compound A (C22H27NO) is insoluble in acid and base but reacts with concentrated aqueous HCl and heat to give a clear aqueous solution from which, on cooling, benzoic acid precipitates. When the supernatant solution is made basic, a liquid B separates. Compound B is achiral. Treatment of B with benzoyl chloride in pyridine gives back A. Evolution of gas is not observed when B is treated with an aqueous solution of NaNO2 and HCl. Treatment of B with excess CH3I, then aqueous Ag2O and heat, gives a compound C, C9H19N, plus styrene, C6H5–CH=CH2. Compound C, when treated with excess CH3I, then aqueous Ag2O and heat, gives a single alkene D that is identical to the compound obtained when cyclohexanone is treated with the ylid –:CH2– PPh3. Give the structure of A.
Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem
A polymer coating of 6:0 mm thickness is cast onto a nonporous flat surface. The coating contains a residual amount of casting solvent, which is uniform at 1.0 wt% within the coating. The mass transfer of solvent through the polymer coating is controlled by molecular diffusion. The air flowing over the coating surface eliminates convective mass-transfer resistances and reduces the solvent vapor concentration in the air to nearly zero. The effective diffusion coefficient of the solvent molecules in the polymer is 2 x 10^-6 cm^2/s.
a. How many hours will it take for the solvent concentration at 1.2 mm from the surface to be reduced to 0.035 wt%?
Answer:
vent vapor concentration in the air to nearly zero. The effective diffusion coefficient of the solvent molecules in the polymer is 2 x 10^-6 cm^2/s
Explanation:
2.92 A 50.0-g silver object and a 50.0-g gold object are both added
to 75.5 mL of water contained in a graduated cylinder. What is
the new water level in the cylinder? (2.7)
ifacturing of computer chins cylinders of silicon
Answer:
82.9 mL
Explanation:
1. Volume of silver
[tex]\begin{array}{rcl}\text{Density}&=& \dfrac{\text{Mass}}{\text{Volume}}\\\\\rho&=& \dfrac{m}{V}\\\\V &=& \dfrac{m}{\rho}\\\\& = & \dfrac{\text{50.0 g}}{\text{10.49 g$\cdot$mL}^{-1}}\\\\& = & \text{4.766 mL}\\\end{array}\\\text{The volume of the silver is $\large \boxed{\textbf{4.766 mL}}$}[/tex]
2. Volume of gold
[tex]\begin{array}{rcl}V& = & \dfrac{\text{50.0 g}}{\text{19.30 g$\cdot$mL}^{-1}}\\\\& = & \text{2.591 mL}\\\end{array}\\\text{The volume of the gold is $\large \boxed{\textbf{2.591 mL}}$}[/tex]
3. Total volume of silver and gold
V = 4.766 mL + 2.591 mL = 7.36 mL
4 New reading of water level
V = 75.5 mL + 7.36 mL = 82.9 mL
6. Find the partial pressures of the gases in a mixture with a total pressure of 101.3 kPa, if there are 7.8 mole of
Ng, 2.1 mole of 0, 0.090 mole of Ar, and 0.010 mol of Co,
3:20
5/10/2
19
110
112
Pause
break
16
X
14
&
*
A
%
7
9
5
6
O
8
4
{
о
Р
Answer:
Explanation:
Total mole of gases = 7.8 + 2.1 + .09 + .01 = 10
the partial pressures of the gases in a mixture
= mole fraction x Total pressure
mole fraction = mole of a gas in the mixture / total mole
partial pressure of Ng = [tex]\frac{7.8}{10} \times 101.3 kPa[/tex]
= 79.014 kPa
partial pressure of O = [tex]\frac{2.1}{10} \times 101.3 kPa[/tex]
= 21.273 kPa .
partial pressure of Ar = [tex]\frac{.09}{10} \times 101.3 kPa[/tex]
= .9117 kPa .
partial pressure of Co = [tex]\frac{.01}{10} \times 101.3 kPa[/tex]
= .1013 k Pa .
Use the graph to determine which is greater, the heat of fusion or the heat of vaporization. Explain how you used the graph to determine that.
(The substance is water)
Answer:
mdjnibfziedosnninjd.zjcssksskskbsksbivfdlvdxkvfuwhiwhwonsk jsbudwuvsaeigdOhgrauvdslnzarm cxwmvakbxsabxwrifwzpgsdoh
ds
Which equation represents conservation of charge?
1. I- + 2e- → I2
2. 2I- → I2 + 2e-
3. Br2 → 2Br- + 2e-
4. Br + 2e- → Br-
Answer:
The answer is 2
Explanation:
The equation that represent the conservation of charge is Option 2.
The following information should be considered:
Conversation of charge represent the total electric charge for an isolated system that should be remains constant regardless of whatever internal changes might have been take place. Therefore, the option 2 is correct.Learn more; https://brainly.com/question/11833983?referrer=searchResults
4. A taxi ride costs $5 plus .75 cents per mile. If I
ride for 120 miles, how much will be charged?
Answer:
$95
Explanation:
.75 x 120 = 90
90+5 = 95
A certain element X has four isotopes. 5.845% of X has a mass of 53.93961 amu. 91.75% of X has a mass of 55.93494 amu. 2.123% of X has a mass of 56.93539 amu. 0.2820% of X has a mass of 57.93328 amu. What is the average atomic mass of element X? Express your answer numerically to four significant figures.
Answer:
Average atomic mass of element X is 56.19 amu
Explanation:
Given:
Four isotopes of X:
5.845% of X has a mass of 53.93961 amu.
91.75% of X has a mass of 55.93494 amu.
2.123% of X has a mass of 56.93539 amu.
0.2820% of X has a mass of 57.93328 amu.
To find: average atomic mass of element X
Solution:
Isotopes are variants of a particular chemical element such that they have the same number of protons but different number of neutrons.
Average atomic mass of element X = [tex]\frac{53.93961+55.93494+56.93539+57.93328}{4}=\frac{224.74322}{4}=56.185805\approx 56.19[/tex]
So, the average atomic mass of element X is 56.19 amu.
If an insufficient amount of liquid unknown had been used, how would this have effected the value of the experimental molar mass
Answer:
Actual yield reduces the more.
Explanation:
An actual yield of the course of a chemical reaction is the mass of a product actually obtained from the reaction.
In practice you see it and It is usually less than the theoretical yield.
Various reasons may come up to explain this away but here is one:
• incomplete reactions, simply put here some of the reactants do not react to form the product.
The same applies in the question about the actual yield will reduce significantly in molar mass now that insufficient amount of reagent are used.
The glass of a lit 75-watt incandescent bulb is hotter to the touch than the glass of a 25-watt compact fluorescent (CFL) bulb that emits the same amount of light. What could be a reason for this
A gas occupies 18.7 L at standard temperature. What is its volume at 200.5 °C
Answer:
32.4 L
Explanation:
Note 1:
The Standard Temperature and Pressure (STP) is defined by IUPAC as air at 0 gradius Celcius and 1 bar.
Note 2:
The Ideal Gas Law is used for solving this problem.
......
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Light brings many chemical changes. Can you think of any chemical change brought about by light?
Answer:
MRCORRECT has answered the question
Explanation:
Film photography is another example ofchemical reaction by light. In this example, the chemical compounds coated on the film go through a chemical reaction. ... These plates (usually made of aluminum) are coated with a photosensitive compound consisting of a polymer and a photosensitivechemical system.
Draw the structure of a compound with the molecular formula CgH1002 that exhibits the following spectral data.
(a) IR: 3005 cm-1, 1676 cm-1, 1603 cm-1
(b) H NMR: 2.6 ppm (singlet, I = 3H), 3.9 ppm (singlet, I = 3H), 6.9 ppm (doublet, I = 2H), 7.9 ppm (doublet, I = 2H)
(c) 13C NMR: 26.2, 55.4, 113.7, 130.3, 130.5, 163.5, 196.6 ppm ?
Answer:
The answer you are looking for is A
A chemist wants to increase the solubility of a solid in water. Which of the
following will NOT help? *
-increase the temperature
-decrease the particle size
-Increase stirring
-increase pressure
Answer:
- Increase pressure .
Explanation:
Hello,
In this case, during the dissolution process, the solute's molecules rearrange in order to get together with the solvent's molecules, in this case water.
Now, since we are talking about a solid whose particles are intimately held together, the only way to separate them is by increasing the temperature because the molecules start moving so they can join water's molecules, decreasing particle size since they will be more likely to separate to each other and increasing stirring since the applied energy will break the solid's intramolecular forces.
In such a way, since pressure significantly affects gases and slightly affects liquid, it is not able to modify a solid, just extreme pressures such as it needed to produce diamonds, is able to affect a solid. For that reason, increasing the pressure will not increase the solid's solubility.
Best regards.
What are 3 stages of the water cycle are
