Answer:
Around 3.62 degrees kelvin
Explanation:
Assuming this is at STP:
The first step is to convert 2600mL to liters. There are 1000 milliliters in a liter, meaning that this is equal to 2.6L.
Now:
[tex]\dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}\\\\\\\dfrac{196(1)}{273}=\dfrac{2.6(1)}{T_2} \\\\\\T_2\approx 3.62K[/tex]
Hope this helps!
which statement describes the reactions in an electrochemical cell
Answer & explanation:
Summary on electrochemical cells and redox reactions:
Electrochemical cells (or batteries) can be defined as devices capable of transforming chemical energy into electrical energy through spontaneous reactions of redox, in which electron transfer occurs.
Redox it is a chemical reaction in which there is the occurrence of oxidation and reduction of atoms of substances (chemical species) present in the process.
Oxidation is the loss of electrons by an atom of a chemical species, while reduction is the gain of electrons by an atom of a chemical species.
Thus, during an oxirreduction reaction, electrons move from the species that loses them towards the species that will receive them. This "movement" results in the formation of an electric current (or electrical energy) as occurs with batteries, for example.
A scientist mixed 25.00 mL of 2.00 M KOH with 25.00 mL of 2.00 M HBr. The temperature of the mixed solution rose from 22.7 oC to 31.9 oC. Calculate the enthalpy change for the reaction in kJ/mol HBr, assuming that the calorimeter loses negligible heat, that the volumes are additive, and that the solution density is 1.00 g/mL, and that its specific heat is 4.184 J/g.oC.
Answer:
38.493 KJ/mol
Explanation:
Equation of reaction; HBr + KOH ---> KBr + H2O
Heat evolved = mass * specific heat capacity * temperature rise
Mass of solution = density * volume
Mass = 1.00 g/ml*50 ml = 50g
Temperature rise = 31.9 - 22.7 = 9.2 °C
Heat evolved = 50 * 4.184 * 9.2 = 1924.64 J
From the equation of reaction, 1 mole of HBr reacts with 1mole of KOH to produce 1 mole of H20
Number of moles of HBr involved in the reaction = molar concentration * volume (L)
Molar concentration = 2.0 M, volume = 25 ml = 0.025 L
Number of moles = 2.0 M * 0.025 L= 0.05 moles
Therefore, 0.05 moles of HBr reacts with 0.05 moles of KOH to produce 0.05 moles of H20
Enthalpy change per mole of HBr = 1924.64 J/0.05 moles = 38492.8 J/mol = 38.493 KJ/mol
What mass of carbon dioxide is produced from the complete combustion of 7.30×10−3 g of methane?
Question 5 of 20:
Select the best answer for the question.
5. Which of the following is a homonuclear diatomic molecule?
O A. NH3
O B. 2002
O C. Hz
O D. CO
Answer:
Homo nuclear molecule mean having atoms of only one element,
I cant see clearly the option B and C can you correct them , 2002? Hz?
Explanation:
Answer:
H2
Explanation:
For the iodine trichloride molecule: a. Determine the number of valence electrons for each atom in the molecule b. Draw the Lewis Dot structure c. Describe why the molecule is drawn this way (i.e. any extra rules/steps needed?) d. Show the polarity of each bond and for the molecule by drawing in the dipole +à
Answer:
Explanation:
a. Determine the number of valence electrons for each atom in the molecule
In this case we both atoms are halogens. Therefore we will have 7 electrons for each atom.
b. Draw the Lewis Dot structure
In this case, the formula is [tex]ICl_3[/tex], so the central atom would be "I" and the "Cl" atoms would be placed around "I". See figure 1
c. Describe why the molecule is drawn this way (i.e. any extra rules/steps needed?)
In this specific case, the "I" atom don't follow the octet rule. We will have an expanded octet for iodine (more than 8 electrons).
d. Show the polarity of each bond and for the molecule by drawing in the dipole +d
The negative dipole would be placed in the atom with higher electronegativity, in this case "Cl". The positive dipole would be placed in the atom with low electronegativity, in this case "I".
I hope it helps!
Nitrogen forms more oxides than any other element. The percents by mass of in three different nitrogen oxides are (1) (II) and (III) 25.94 For each compound, determine (a) the simplest whole-number ratio of to and (b) the number of grams of oxygen per 1.00 of nitrogen.
Complete question;
Nitrogen forms more oxides than any other element. The percents by mass of N in three different nitrogen oxides are (|) 46.69%;(II) 36.85 %; (III) 25.94%. For each compound, determine (a) the simplest whole-number ratio of N to O, and (b) the number of grams of oxygen per 1.00 g of nitrogen.
Answer:
a. (i) The ratio is 1:1 , the formula = NO (ii)The ratio is 1 : 1.5 which is 2 : 3, the formula = N₂O₃ (iii) The ratio is 1 : 2.5 which is 2:5 , the formula = N₂O₅
b. (i)number of grams of oxygen = 53.31/46.69 = 1.14 g
(ii)number of grams of oxygen = 63.15/36.8 = 1.71 g
(iii)number of grams of oxygen = 74.06/25.94 = 2.855 g
Explanation:
a.
(i) The percentage by mass of the nitrogen in Nitrogen oxide (i) is 46.69% which is taken as 46.69 grams . Since the other element is oxygen the mass of oxygen will be 100 - 46.69 = 53.31 grams.
The relative atomic mass of Nitrogen and oxygen is 14 amu and 16 amu respectively.
Therefore, to know the whole number ratio of N and O we find the number of moles.
number of moles of N = 46.69/14 = 3.335
number of moles of O = 53.31/16 = 3.332
The ratio is 1:1 , the formula = NO
(ii)
number of moles of N = 36.85/14 = 2.632
number of moles of O = 63.15/16 = 3.947
The ratio is 1 : 1.5 which is 2 : 3, the formula = N₂O₃
(iii)
number of moles of N = 25.94/14 = 1.85
number of moles of O = 74.06/16 = 4.63
The ratio is 1 : 2.5 which is 2:5 , the formula = N₂O₅
b.
(i) 46.69 g of nitrogen = 53.31 g of oxygen
1 g of nitrogen = ? of Oxygen
number of grams of oxygen = 53.31/46.69 = 1.14 g
(ii)
Using similar method in b(i)
number of grams of oxygen = 63.15/36.8 = 1.71 g
(iii)
Using similar method in b(i)
number of grams of oxygen = 74.06/25.94 = 2.855 g
¿What are the units that make up the 3 quantities (mass, volume of a substance and density)?
Answer:
Grams , centimeters cubed, and grams per centimeter
Explanation:
Liquid hexane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 4.3 g of hexane is mixed with 7.14 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
We can produce 6.20 grams of CO2
Explanation:
Step 1: Data given
Mass of hexane = 4.3 grams
Molar mass of hexane = 86.18 g/mol
Mass of oxygen = 7.14 grams
Molar mass of oxygen = 32.0 g/mol
Step 2: The balanced equation
2C6H14 + 19O2 → 12CO2 + 14H2O
Step 3: Calculate moles
Moles = mass / molar mass
Moles hexane = 4.3 grams / 86.18 g/mol
Moles hexane = 0.0499 moles
Moles oxygen = 7.14 grams / 32.0 g/mol
Moles oxygen = 0.2231 moles
Step 4: Calculate the limiting reactant
For 2 moles hexane we need 19 moles O2 to produce 12 moles CO2 and 14 moles H2O
Oxygen is the limiting reactant. It will completely be consumed ( 0.2231 moles). Hexane is in excess. There will react 2/19 * 0.2231 = 0.02348 moles
There will be porduced 12/19 * 0.2231 = 0.1409 moles CO2
Step 5: Calculate mass CO2
Mass CO2 = moles CO2 * molar mass CO2
Mass CO2 = 0.1409 moles * 44.01 g/mol
Mass CO2 = 6.20 grams
We can produce 6.20 grams of CO2
A sample of thallium(III) peroxide, Tl2(O2)3, contains 2.45 mol of thallium(III) ions. The number of moles of peroxide ions in the sample is
Answer:
The correct answer is 3.675 moles.
Explanation:
Based on the question, the reaction taking place is,
Tl₂(O₂)₃ ⇒ 2Tl⁺³ + 3O₂⁻²
Thus, 1 mole of thallium peroxide comprise 2 moles of thallium and 3 moles of peroxide ions.
However, based on the given question, a sample of thallium peroxide comprise 2.45 moles of thallium ions. The moles of peroxide ions present in the sample will be,
= 2.45 × 3 / 2
= 3.675 moles.
Hence, the moles of peroxide ions present in the given sample is 3.675.
Pyruvate is the end product of glycolysis. Its further metabolism depends on the organism and on the presence or absence of oxygen. Draw the structure of the product from each reaction as it would exist at pH 7. Include the appropriate hydrogen atoms. Reaction A: aerobic conditions in humans or yeast
The given question is incomplete. The image present in the question for Reaction A is attached below along with the answer.
Explanation:
Pyruvate molecule reacts with Coenzyme A in the presence of oxygen and it results in the formation of acetyl Coenzyme A and carbon dioxide.
The enzyme pyruvae dehydrogenase helps in catalyzing this reaction. As in this biochemical reaction [tex]NAD^{+}[/tex] gets converted into NADH.
This reaction is shown in the image attached below.
dropping an Alka-Seltzer tablet into a glass of water _________________________________________ b. bleaching a stain _________________________________________ c. burning a match _________________________________________ d. rusting of an iron nail
Answer:
Hi there!
When dropping Alka-Seltzer into a glass of water, bubbles immediately appear and the solid substance “disappears”, dissolves, into the water. This forms a new compound, a liquid, which means a reaction took place.
Suppose the amount of a certain radioactive substance in a sample decays from to over a period of days. Calculate the half life of the substance. Round your answer to significant digit.
The given question is incomplete, the complete question is:
Suppose the amount of a certain radioactive substance in a sample decays from 1.30 mg to 100. ug over a period of 29.5 days. Calculate the half life of the substance Round your answer to 2 significant digits.
Answer:
The correct answer is 7.974 days.
Explanation:
Based on the given question, the concentration of a radioactive substance present in a sample get decays to 100 micro grams from 1.30 milligrams in 29.5 days. There is a need to find the half-life of the substance.
Radioactive decay is an illustration of first order reaction.
K = (2.303 / t) log [a/(a-x)]
Here a is 1.30 mg and (a-x) is 100 micrograms = 100 * 10^-3 mg or 0.1 mg, and t is 29.5 days. Now putting the values we get,
K = (2.303 /29.5)log (1.30/0.1)
= 2.303/29.5 log13
= 2.303/29.5 * 1.1139
K = 0.0869
The half-life or t1/2 is calculated by using the formula, 0.693 / K
= 0.693 / 0.0869
= 7.974 days.
What will be the final temperature when a 25.0 g block of aluminum (initially at 25 °C) absorbs 10.0 kJ of heat? The specific heat of Al is 0.900 J/g·C.
42.1°C is the final temperature when a 25.0 g block of aluminum (initially at 25 °C) absorbs 10.0 kJ of heat.
What is temperature?The physical concept of temperature indicates in numerical form how hot or cold something is. A thermometer is used to determine temperature. Thermometers are calibrated using a variety of temperature scales, which historically defined distinct reference points or thermometric substances.
The most popular scales include the Celsius scale, sometimes known as centigrade, with the unit symbol °C, the scale of degrees Fahrenheit (°F), or the Kelvin scale (K), with the latter being mostly used for scientific purposes. One of the United Nations System of Units' (SI) seven base units is the kelvin.
Q=725 J
m=55.0 g
c=0.900 J/(°C⋅g)
ΔT=final temperature - initial temperature
ΔT=(x−27.5)°C
725 J=55.0 g⋅0.900 J/(°C⋅g)(x−27.5)
X=42.1°C
Therefore, 42.1°C is the final temperature when a 25.0 g block of aluminum (initially at 25 °C) absorbs 10.0 kJ of heat.
To know more about temperature, here:
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molar mass of A1C1 3
Answer:
Gold(III) chloride
One of the reagents below gives predominantly 1,2 addition (direct addition) while the other gives predominantly 1,4 addition (conjugate addition). a) Which major organic product is the result of 1,2 addition? ---Select--- b) Draw the skeletal structure of major organic product A
Complete Question
The complete question is shown on the first uploaded image
Answer:
a
The correct option is reagent B
b
The skeletal structure of major organic product A is shown on the third uploaded image
Explanation:
The mechanism of the reaction for A and B are shown on the second the second reaction and looking at this we can see that the reagent that predominately gives 1,2 addition is reagent B
Which of the following errors could cause your percent yield to be falsely high, or even over 100%?
Select ALL that apply.
A.) Heating the sample too vigorously.
B.) Handling the crucible directly with your hands.
C.) Failing to completely decompose the sodium bicarbonate sample.
D.) Taking the mass of the empty crucible without the lid, but including the lid in all other mass measurements.
E.) Taking the mass of all samples with the lid included.
Answer:
B.Handling the crucible directly with your hands.
D.Taking the mass of the empty crucible without the lid, but including the lid in all other mass measurements.
E.Taking the mass of all samples with the lid included.
Explanation:
When observed critically , the measures associated with the errors which could cause your percent yield to be falsely high, or even over 100% are those which increase the weight of the substance with the individual neglecting.
Handling the crucible directly with your hands,Taking the mass of the empty crucible without the lid, but including the lid in all other mass measurements and taking the mass of all samples with the lid included will all increase the weight of the substance. Instead the substance should be placed alone without any form of support or contamination.
A chemistry student weighs out of an unknown solid compound and adds it to of distilled water at . After minutes of stirring, only some of the has dissolved. The student drains off the solution, then washes, dries and weighs the that did not dissolve. It weighs 0.570 kg.
Required:
a. Using the information above, can you calculate the solubility of X?
b. If so, calculate it. Remember to use the correct significant digits and units. .
Complete Question
A chemistry student weighs out 0.950 kg of an unknown solid compound and adds it to 2.00 L of distilled water at . After minutes of stirring, only some of the has dissolved. The student drains off the solution, then washes, dries and weighs the that did not dissolve. It weighs 0.570 kg.
Required:
a. Using the information above, can you calculate the solubility of X?
b. If so, calculate it. Remember to use the correct significant digits and units. .
Answer:
a
Yes the solubility of X can be calculated this is because the solubility of a substance dissolved in a solution is the amount of that substance that is needed to saturate 1 unit volume of the solvent solution at that given temperature.
And from our question we see that substance X saturated the solvent and there is still remained undissolved substance X
b
The solubility of X is [tex]S = 190 g /L[/tex]
Explanation:
From the question we are told that
The initial mass of the unknown solid is [tex]m_i =0. 950 \ kg[/tex]
The mass of the undissolved substance is [tex]m_u = 0.570 \ kg[/tex]
The volume of the solution is [tex]V =2.00\ L[/tex]
Yes the solubility of X can be calculated this is because the solubility of a substance dissolved in a solution is the amount of that substance that is needed to saturate 1 unit volume of the solvent solution at that given temperature.
And from our question we see that substance X saturated the solvent and there is still remained undissolved substance X
The mass of the substance that dissolved ([tex]m_d[/tex] ) is mathematically represented as
[tex]m_d = m_i - m_u[/tex]
[tex]m_d = 0.95 - 0.570[/tex]
[tex]m_d = 0.38 \ kg = 0.38 *1000 = 380 g[/tex]
The solubility of this substance (X) is mathematically represented as
[tex]S = \frac{m_d}{V}[/tex]
substituting values
[tex]S = \frac{ 380}{2}[/tex]
[tex]S = 190 g /L[/tex]
Consider a cobalt-silver voltaic cell that is constructed such that one half-cell consists of the cobalt, Co, electrode immersed in a Co(NO3)3 solution, and the other half-cell consists of the silver, Ag, electrode immersed in a AgNO3 solution. The two electrodes are connected by a copper wire. The Co electrode acts as the anode, and the Ag electrode acts as the cathode. To maintain electric neutrality, you add a KNO3 salt bridge separating the two half-cells. Use this information to solve Parts B, C, and D.
A. The half-cell is a chamber in the voltaic cell where one half-cell is the site of the oxidation reaction and the other half-cell is the site of the reduction reaction.
Type the half-cell reaction that takes place at the anode for the cobalt-silver voltaic cell. Indicate the physical states using the abbreviation (s), (l), or (g) for solid, liquid, or gas, respectively. Use (aq) for an aqueous solution. Do not forget to add electrons in your reaction.
B. The half-cell is a chamber in the voltaic cell where one half-cell is the site of an oxidation reaction and the other half-cell is the site of a reduction reaction.
Type the half-cell reaction that takes place at the cathode for the cobalt-silver voltaic cell. Indicate physical states using the abbreviation (s), (l), or (g) for solid, liquid, or gas, respectively. Use (aq) for an aqueous solution. Do not forget to add electrons in your reaction.
Answer:
Anode half reaction;
Co(s) ----> Co^2+(aq) + 2e
Cathode half reaction;
2Ag^+(aq) + 2e-------> 2Ag(s)
Explanation:
A voltaic cell is an electrochemical cell that spontaneously produces electrical energy from chemical reactions. A voltaic cell comprises of an anode (where oxidation occurs) and a cathode (where reduction occurs). The both electrodes are connected with a wire . A salt bridge ensures charge neutrality in the anode and cathode compartments. Electrons flow from anode to cathode.
For the cell referred to in the question;
Anode half reaction;
Co(s) ----> Co^2+(aq) + 2e
Cathode half reaction;
2Ag^+(aq) + 2e-------> 2Ag(s)
Unscramble the following words to form a complete
sentence about the cycles of nature:
limited is through environment Matter recycled the on Earth is and
Answer:
recycled is limited through enviroment and matter on earth
Explanation:
The boiling of water is a:_______.
a. chemical change because a gas (steam) is given off.
b. chemical change because heat is needed for the process to occur.
c. physical change because the water merely disappears chemical and physical damage.
d. physical change because the gaseous water is chemically the same as the liquid.
Answer:
D
Explanation:
trust me its correct i think
a introduction paragraph about coal and natural gas
Answer:
here is ur and
Explanation:
Coal, oil and natural gas are called fossil fuels. Fossil fuels are burned to make energy. Burning fossil fuels also releases CO2 (carbon dioxide) gas into the atmosphere. Most air pollutants (such as sulfur dioxide) don't stay in the atmosphere very long.
pls mark.me as brainliest
Given a K value of 0.43 for the following aqueous equilibrium, suppose sample Z is placed into water such that it’s original concentration is 0.033 M. Assume there was zero initial concentration of either A(aq) or B(aq). Once equilibrium has occurred, what will be the equilibrium concentration of Z?
2A(aq) + B(aq) <> 2Z (aq)
Answer:
[Z] = 0.00248M
Explanation:
Based in the reaction:
2A(aq) + B(aq) ⇄ 2Z (aq)
K of the reaction is defined as:
K = [Z]² / [A]²[B] = 0.43
If you add, in the first, just 0.033M of Z, concentrations in equilibrium are:
[Z] = 0.033M - 2X
[A] = 2X
[B] = X
Replacing in K equation:
0.43 = [0.033M - 2X]² / [2X]² [X]
0.43 = [0.033M - 2X]² / [2X]² [X]
0.43 = 4X² -0.132X + 0.001089 / 4X³
1.72X³ - 4X² + 0.132X - 0.001089 = 0
Solving for X:
X = 0.01526M
Replacing, concentration in equilibrium of Z is:
[Z] = 0.033M - 2*0.01526M = 0.00248M
Answer:
Less than 0.033 M
Explanation:
Hello,
In this case, given the equilibrium:
[tex]2A(aq) + B(aq) \rightleftharpoons 2Z (aq)[/tex]
Thus, the law of mass action is:
[tex]K=\frac{[Z]^2}{[A]^2[B]}[/tex]
Nevertheless, given the initial concentration of Z that is 0.033 M, we should invert the equilibrium since the reaction will move leftwards:
[tex]\frac{1}{K} =\frac{[A]^2[B]}{[Z]^2}=2.33[/tex]
Know, by introducing the change due to the reaction extent, we can write:
[tex]2.33=\frac{(2x)^2*x}{(0.033M-2x)^2}[/tex]
Which has the following solution:
[tex]x_1=2.29M\\x_2=0.0181M\\x_3= 0.0153M[/tex]
But the correct solution is [tex]x=0.0153M[/tex] since the other solutions make the equilibrium concentration of Z negative which is not possible. In such a way, its concentration at equilibrium is:
[tex][Z]_{eq}=0.033M-2*0.0153M=0.0024M[/tex]
Which is of course less than 0.033 M since the addition of a product shift the reaction leftwards in order to reestablish equilibrium (Le Chatelier's principle).
Regards.
Gold can be separated from sand by panning or by a sluice-box. In panning, water is mixed with the sand and the resulting slurry is swirled in a shallow, saucer-shaped metal pan. In the sluice-box technique, running water is passed over an agitated sand- gold mixture. What physical property and what technique make this separation possible?
Answer:
Decantation by means of difference in relative densities.
Explanation:
The specific gravity (relative density) of the gold to the soil/sand is the physical property exploited in panning gold. The particles with lower density would float whilst the heavier gold sinks lower to the bottom of the pan by gravity and is decanted off.
I hope this explanation is easy to comprehend.
During lab, you evaluated the bond order and bond length of a series of carbon-carbon bonds. Use the same concepts to predict the bond order and bond length of a series of nitrogen-nitrogen bonds.(a) Which of the structures below have a nitrogen-nitrogen bond order of 3?(b) Which of the structures below have the shortest nitrogen-nitrogen bond?
Answer:
N≡N
Explanation:
The image attached shows the nitrogen compounds that are being referred to in the question.
There are certain things we ought to know in order to answer the question accurately.
The bond order of a compound is equal to the number of bonds between two atoms. The greater the bond order, the shorter the bond length between the two atoms.
N≡N has a bond order of three, this is the highest bond order among all the species listed in the question. Hence it has the shortest bond length among the trio. Hence the answer.
A compound D with the molecular formula C6H12 is optically inactive but can be resolved into enantiomers. On catalytic hydrogenation, D is converted to E (C6H14) and E is optically inactive. Propose structures for D and E. (Draw a three-dimensional formula for each using dashes and wedges around chiral centers.)
Answer:
D: CH2=CH-CH(CH3)-CH2-CH3 (R & S enantiomers)
E: CH3-CH2-(CH3)-CH2-CH3
(Please see the figures enclosed )
Explanation:
D is a racemic mixture (R & S) of 3-metyl-pent-1-ene, so it is optically inactive (although each of two enantiomers is optically active, the mixture is optically inactive. The reason is that two enantiomers are present in an equal amount).
E is optically inactive, so its structure has to be symmetric.
Consider the following specific heats of metals. Metal Specific Heat Aluminum 0.897 J/(g°C) Magnesium 1.02 J/(g°C) Lithium 3.58 J/(g°C) Silver 0.237 J/(g°C) Gold 0.129 J/(g°C) If the same amount of heat is added to 25.0 g of each of the metals, which are all at the same initial temperature, which metal will have the lowest temperature?
Answer:
Lithium
Explanation:
The specific geat capacity of a substance is the energy required to raise 1 unit of that substance by one degree.
Heat energy (Q) = mc∇t
Q = heat energy
M = mass of the substance
c = specific heat capacity
∇t = change in temperature of the substance
Generally, increase in the specific heat capacity will lead to a lower final temperature likewise decrease in the specific heat capacity will lead to increase the final temperature of the substance.
From the data above, we can take just two specific heat capacity and test this theory.
Assuming we have a
Mass = 25g
Heat energy applied (Q) = 1 J
Initial temperature (T1) = 10°C
Final temperature (T2) = ?
Q = mc∇t
Q = mc (T2 - T1)
For Lithium, specific heat capacity = 3.58J/g°C
1 = 25 × 3.58 (T2 - 10)
Solve for T2
1 = 89.5 (T2 - 10)
1 = 89.5T2 - 895
89.5T2 = 896
T2 = 896 / 89.5
T2 = 10.011°C
For Magnesium (Mg) specific heat capacity = 1.02J/g°C
Q = mc∇t
1 = 25 × 1.02 × (T2 - 10)
1 = 25.5 (T2 - 10)
1 = 25.5T2 - 255
Solve for T2
25.5T2 = 256
T2 = 10.039°C
Notice the trend that decrease in the specific heat capacity leads to increase in the final temperature.
Try and continue for the elements and see how it works.
The breaking buffer that we use this week contains 10mM Tris, pH 8.0, 150mM NaCl. The elution buffer is breaking buffer that also contains 300mM imidazole. Describe how the instructor made the 0.25L elution buffer for all the students this week given 500ml of 1M of Tris (121.1 g/mole) (pH8.0), 750ml of 5M NaCl (MW
Answer:
Explanation:
From the given information ;the objective is to determine how the instructor made the 0.25L elution buffer
0.25 L elution buffer = 250 mL elution butter
The breaking buffer that we use this week contains
10mM Tris = 0.01 M
150mM NaCl = 0.15 M
300mM imidazole. = 0.3 M
The stock concentration of Tris in 1M
Therefore ; by using the formula: [tex]M_1V_1 = M_2 V_2[/tex]; we can determine the volume in the preparation; so;
[tex]1*V_1 = 0.0 1 \ M * 250 \ mL[/tex]
[tex]V_1 = \dfrac{0.0 1 \ M * 250 \ mL}{1 }[/tex]
[tex]V_1 = 2.5 \ mL[/tex]
In NaCl, The amount of stock concentration is 5 M
so; using the same formula; we have:
[tex]5*V_1 = 0.15 \ M * 250 \ mL[/tex]
[tex]V_1 = \dfrac{0. 15 \ M * 250 \ mL}{5 }[/tex]
[tex]V_1 = 7.5 \ mL[/tex]
From Imidazole ; the amount of stock concentration is
[tex]1*V_1 = 0.3 \ M * 250 \ mL[/tex]
[tex]V_1 = \dfrac{0. 3 \ M * 250 \ mL}{1 }[/tex]
[tex]V_1 = 75 \ mL[/tex]
Thus; we can have a table as shown as :
Stock concentration volume to be added Final concentration
1 M of Tris 2.5 mL 10 mM
5 M of NaCl 7.5 mL 150 mM
1 M of Imidazole 75 mL 300 mM
In conclusion. the addition of all the volume make up the 250 mL elution buffer that is equivalent to 0.25 L.
Classify the following unbalanced chemical reaction Fe(s) + Cl2(aq) = Fe2+(aq) + Cl-(aq)
1. Acid-Base Reaction
2. Precipitation Reaction
3. Oxidation-Reduction Reaction
4. Combustion Reaction
Answer:
3. Oxidation-Reduction Reaction
Explanation:
Fe(s) + Cl2(aq) = Fe2+(aq) + Cl-(aq)
Fe(s) -2e- ----> Fe2+(aq) oxidation
Cl2(aq) + 2e- -----> 2Cl-(aq) reduction
The given unbalanced chemical reaction is the oxidation-reduction reaction. Therefore, option (3) is correct.
What is an oxidation-reduction reaction?Redox reactions can be defined as oxidation-reduction chemical reactions in which the reactants of the reaction undergo a change in their oxidation states. All the redox reactions are further broken down into two different processes: a reduction process and an oxidation process.
The oxidation and reduction reactions take place simultaneously in an Oxidation-Reduction reaction. The substance that is getting reduced in a reaction is known as the oxidizing agent, while a substance that is getting oxidized is the reducing agent.
The given chemical reaction is:
[tex]Fe(s) + Cl_2(aq) \longrightarrow Fe^{2+}(aq) + Cl^-(aq)[/tex]
The oxidation reaction for this reaction is: Fe (s) → Fe²⁺ (aq) + 2e⁻
The reduction reaction: Cl₂ (g) + 2e⁻ → 2Cl⁻ (aq)
Therefore, the given reaction between the iron and chlorine gas is the oxidation-reduction reaction or redox reaction.
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Identify the Lewis acids and Lewis bases in the following reactions:
1. H+ + OH- <-> H2O Lewis acid: Lewis base:
2. Cl- + BCl3 <-> BCl4- Lewis acid: Lewis base:
3. K+ + 6H2O <-> K(H2O)6+ Lewis acid: Lewis base:
Answer: 1. [tex]H^++OH^-\rightarrow H_2O[/tex] Lewis acid : [tex]H^+[/tex], Lewis base : [tex]OH^-[/tex]
2. [tex]Cl^-+BCl_3\rightarrow BCl_4^-[/tex] Lewis acid : [tex]BCl_3[/tex], Lewis base : [tex]Cl^-[/tex]
3. [tex]K^++6H_2O\rightarrow K(H_2O)_6[/tex] Lewis acid : [tex]K^+[/tex], Lewis base : [tex]H_2O[/tex]
Explanation:
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
1. [tex]H^++OH^-\rightarrow H_2O[/tex]
As [tex]H^+[/tex] gained electrons to complete its octet. Thus it acts as lewis acid.[tex]OH^-[/tex] acts as lewis base as it donates lone pair of electrons to electron deficient specie [tex]H^+[/tex].
2. [tex]Cl^-+BCl_3\rightarrow BCl_4^-[/tex]
As [tex]BCl_3[/tex] is short of two electrons to complete its octet. Thus it acts as lewis acid. [tex]Cl^-[/tex] acts as lewis base as it donates lone pair of electrons to electron deficient specie [tex]BCl_3[/tex].
3. [tex]K^++6H_2O\rightarrow K(H_2O)_6[/tex]
As [tex]K^+[/tex] is short of electrons to complete its octet. Thus it acts as lewis acid. [tex]H_2O[/tex] acts as lewis base as it donates lone pair of electrons to electron deficient specie [tex]K^+[/tex].
Which of the following best describe an atomic number? An element identity is defined by its atomic number this means it represents the number of
a)Atomic number is the number of protons in the nucleus of an atom.
b)atomic number represents the number of protons
An element's identity is defined by its atomic number; this means it represents the number of protons in its nucleus.
The question is incomplete, the complete question is;
Which of the following best describes an atomic number? An element's identity is defined by its atomic number; this means it represents the number of
A) protons plus neutrons in its nucleus.
B) electrons in the element.
C) protons in its nucleus.
D) neutrons in its nucleus.
The subatomic particles in the atom are;
ElectronsProtonsNeutronsNeutrons and protons are contained in the nucleus hence they are collectively called nucleons.
Electrons are found in the orbits. The number of protons must be equal to the number of electrons for the atom to be electrically neutral.
The number of protons in an atom or atomic number serve as a means of identifying an atom.
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