Answer:
18.308 KJ
Explanation:
From the given above, we obtained the following:
Activation energy for the catalyzed reaction = 4.6 kJ.
Activation energy for the uncatalyzed reaction =..?
Now, a careful observation of the question revealed that the activation energy of the uncatalyzed reaction is about 3.98 times that of the catalyzed reaction.
With this vital information, we can thus, calculate the activation energy of the uncatalyzed reaction as follow:
Activation energy for the uncatalyzed reaction = 3.98 times that of the catalyzed reaction.
Activation energy for the uncatalyzed reaction = 3.98 x 4.6 kJ = 18.308 KJ
Therefore, the activation energy of the uncatalyzed reaction is 18.308 KJ.
how many moles of a solute is present in 4.00L of an 8.30M solution
Answer:
The number of moles of solute present in 4.00 L of an 8.30 M solution is 33.2
Explanation:
The Molarity (M) or Molar Concentration is the number of moles of solute per liter of solution; in other words it is the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units ([tex]\frac{moles}{liter}[/tex]) or M.
In this case:
molarity= 8.30 Mnumber of moles of solute= ?volume= 4.00 LReplacing:
[tex]8.30 M=\frac{number of moles of solute}{4 L}[/tex]
Solving:
number of moles of solute= 8.30 M* 4 L= 8.30 [tex]\frac{moles}{liter}[/tex] * 4 L
number of moles of solute =33.2
The number of moles of solute present in 4.00 L of an 8.30 M solution is 33.2
Answer:
33.2 is the answer
Explanation:
did the test already :)
why homoannular diene in uv spectrometry have higher wavlenth than hetroannular diene?
Answer:
Homoanular dienes have a greater base value than heteroanular dienes
Explanation:
Woodward in 1945 gave a set of rules relating the wavelength of maximum absorption to the structure of a compound. These rules were modified by Fieser in 1959. These sets of rules describe the absorption of organic molecules in the UV region of the electromagnetic spectrum.
Each system of diene or triene has a given fixed value at which maximum absorption is expected to occur according to Woodward rules. This given fixed value is called the base or parent value. If the two double bonds are trans to each other, the diene is said to be transoid. If the two double bonds belong to different rings, the system is said to be heteroanular and the base value in each case is 215nm. If the double bonds are cis to each other (cisoid), or the two double bonds are in the same ring (homoanular), then the base value is 253nm.
Since λmax = base value + ∑ substituent contributions + ∑ other contributions, if the other contributions are not very significant, homoanular diene will have a greater λmax because of its larger base value compared to heteroanular diene. This correlates well with the fact that conjugated systems absorb at a longer wavelength.
What is the electron configuration for N (nitrogen)?
A. 1521p5
B. 1s22s23s 3p
O cly 1s22s22p3
O D. 1s 2s22p 3s
SUBMIT
Answer:
[tex]1s^22s^22p^3[/tex]
Explanation:
Nitrogen has the atomic number = 7
So, No. of electrons = 7
Electronic Configuration:
[tex]1s^22s^22p^3[/tex]
Remember that:
s sub shell holds upto 2 electrons while p sub shell upto 6
Define dew point in complete sentences
How many carbon atoms are represented by the model below
A) 0
B) 3
C) 2
D) 1
Answer:
Option (B) 3.
Explanation:
In the model represented above, the two extreme represent carbon atoms since no other group are attached to it. The joint at the middle also represent carbon atom.
Thus, we can write a more simplify illustration for the model above as
C—C—C
From the above illustration, we can see that the model contains 3 carbon atom.
A compound has a mass percentage of 53.46% C, 6.98% H, and 39.56% O. What is the empirical formula for this compound
Answer:
The empirical formula is: C₂H₃O
Explanation:
The empirical formula, also known as the “minimum formula”, is the simplest expression to represent a chemical compound and indicates the elements that are present and the minimum integer ratio between its atoms.
The percentage composition is the percentage by mass of each of the elements present in a compound.
Having 100 g of the compound as a base, it is possible to express the percentages in grams. That is, assuming you have 100 g of the compound, you have 53.46 g of C , 6.98 g of H , and 39.56 g of O.
Taking into account the molecular mass of each substance, the number of relative atoms of each chemical element is calculated:
C: [tex]53.46 g *\frac{1 mol}{12.01 g } = 4.45 moles[/tex]
H:[tex]6.98 g *\frac{1 mol}{1.01 g } = 6.91 moles[/tex]
O:[tex]39.56 g *\frac{1 mol}{16g } = 2.47 moles[/tex]
Now you divide each value obtained by the least of them:
C: [tex]\frac{4.45 moles}{2.47 moles}= 1.80[/tex]
H:[tex]\frac{6.91 moles}{2.47 moles}= 2.8[/tex]
O:[tex]\frac{2.47 moles}{2.47 moles}=1[/tex]
Decimals approach the nearest integer, then:
C: 2
H: 3
O: 1
Therefore the empirical formula is: C₂H₃O
Answer: The other guy is wrong. The correct answer is C9H14O5
Explanation:
et the mass percentages from the percent composition represent grams in a total mass of 100g. Use the grams to calculate the number of moles of each atom present.
%C:53.46%molC=53.46gC=53.46gC×1molC12.011gC=4.451molC
%H:6.98%molH=6.98gH=6.98gH×1molH1.008gH=6.924molH
%O:39.56%molO=39.56gO=39.56gO×1molO15.999gO=2.473molO
Divide by the smallest number of moles.
subscriptC=4.451molC2.473molO≈1.800≈95
subscriptH=6.924molH2.473molO≈2.800≈145
subscriptO=2.473molO2.473molO=1
Now, multiply each subscript by 5 to achieve whole number subscripts. Therefore, the empirical formula is C9H14O5.
What would have happened to your % Transmittance reading and to your calculations of Keq if the spectrophotometer had been set at 520 nm rather than 447nm
Answer:
On the off chance that the wavelength(λ) maximum worth has been changed to 520 nm from 470 nm on the spectrophotometer, less light would be absorbed and in this way %T would be higher than the one found at 470 nm. The wavelength utilized at 520 nm isn't adequate for the excitation and consequently lesser light is absorbed by the arrangement.
Explanation:
A spectrophotometer is an analytical equipment used to quantitatively gauge the transmission(passage) or impression of visible light, UV light or infrared light through a medium.
Transmittance (τ) is the ratio of the brilliant or luminous flux at a given wavelength that is transmitted to that of the incident radiation.
where, Keq is the equilibrium constant.
On the off chance that the wavelength(λ) has been changed to 520 nm from 470 nm on the spectrophotometer, less light would be absorbed and in this way %T would be higher than the one found at 470 nm.
What happens to Transmittance?A spectrophotometer is an analytical equipment used to quantitatively gauge the transmission(passage) or impression of visible light, UV light or infrared light through a medium. Transmittance (τ) is the ratio of the brilliant or luminous flux at a given wavelength that is transmitted to that of the incident radiation. The wavelength utilized at 520 nm isn't adequate for the excitation and consequently lesser light is absorbed by the arrangement. As the concentration goes up, more radiation is absorbed and the absorbance goes up. Therefore, the absorbance is directly proportional to the concentration.
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What is T2, if T1= 500 k, v1=10L, V2=8L,P1=600 torr,P2=200 torr?
Answer:
T2 = 133.333°K
Explanation:
Using Combined Gas Laws:
(600 torr)(10L)/500°K = (200 torr)(8L)/x°K
[tex]\frac{600 torr(10L)}{500K} =\frac{200 torr(8L)}{xK}[/tex]
Cross multiply:
x°K (600 torr)(10L) = 500°K(200 torr)(8L)
Divide:
x°K = (500°K(200 torr)(8L))/(600 torr)(10L)
[tex]xK = \frac{500K(200 torr)(8L)}{600 torr(10L)}[/tex]
x = 400/3°K or 133.333°K
warming oceans temperatures directly lead to all of the following except A sea level rising B coral bleaching C ocean deoxigenation D pollution
Answer:
D. pollution
Explanation:
Increase in ocean temperature is one of the major consequence of global warming which directly leads to rise in sea level, coral bleaching and ocean deoxygenation.
Warming ocean temperatures do not leads to pollution directly whereas pollution leads to warming ocean temperatures. So, in the case of pollution, the effect is opposite.
Hence, the correct option is D.
You've just synthesized a new molecule and need to purify it by recrystallization. You find that it is poorly soluble in water and highly soluble in ethanol, even when cooled in ice. What solvent should work in this situation
Answer:
Water is used as a solvent.
Explanation:
In order to purify the new molecule, recrystallization occurs in which the new molecule should be added in water and heated the water in order to increase the solubility of the solution. The new molecule dissolve in water while the impurity remains undissolved which can be removed from the solution and then remain the solution to be cold down and the new molecule will again undissolved and the molecule can be extracted without any impurities. We use water instead of ethanol due to lower solubility.
MnBr2 molecular or ionic:
name:
molecular or ionic
Answer: Manganese(II)bromide
Explanation:
Because it is a chemical compound composed of manganese and bromine
A buffer solution is all of the following EXCEPT: a solution that contains both a weak acid and its conjugate base. a solution that resists a change in pH when a base is added. a solution that regulates pH because it is such a strong acid or base. a solution that resists a change in pH when an acid is added. All of the above are true.
Answer:
A SOLUTION THAT REGULATES pH BECAUSE IT IS SUCH A STRONG ACID OR BASE
Explanation:
A buffer solution is an aqueous solution consisting of a weak acid and its conjugate base. It is an aqueous solution used to keep the pH of solution at a nearly constant value in various chemical processes. It resists change in pH when either a strong acid or a strong base is added. So it is very essential in various chemical applications and even in the human body as the blood pH is kept in nearly constant value by the bicarbonate buffer system in conjunction with the kidneys. The buffer solution is able to keep this nearly constant range of values because of the equilibrium between the weak acid and its conjugate base. So therefore, the incorrect statement in the options is that buffer solution is a solution that regulates pH because it is such a strong acid or base. The other options are correct.
Arrange the following set of atoms in order of decreasing atomic size: Sn, I, Sr
Which atom has the largest atomic size?
a) Sn
b) I
c) Sr
Which atom has the smallest atomic size?
a) Sn
b) I
c) Sr
How are sodium (Na) and potassium (K) similar?
O
A. They rarely react.
B. They are hard metals.
O O
C. They are highly reactive.
D. They are soft nonmetals.
Answer:
They are also relatively soft metals: sodium and potassium can be cut with a butter knife.
Answer:A
Explanation:
oxidation number of Se in Se8
Answer:
0.
Explanation:
All elements existing on their own in their free states has an oxidation number of 0.
The oxidation number of Se in Se8 is 0. The element Se in its elemental state has an oxidation number of 0.
Chemistry uses the idea of oxidation number, also known as oxidation state, to describe the charge that an atom seems to have when it forms a compound or ion. It is a notion that aids in our comprehension of how electrons are distributed within a molecule or ion. Oxidation numbers can be used to balance chemical equations and identify the many kinds of chemical reactions that may take place. For a better understanding of the reactivity and bonding of various elements in compounds, they offer insights into the transfer or sharing of electrons between atoms. Se in Se8 has an oxidation number of 0. Se has an oxidation number of 0 when it is in its purest form.
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g A laboratory analysis of an unknown compound found the following composition: C 75.68% ; H 8.80% ; O 15.52%. What is the empirical formula of the compound?
Answer:
THE EMPIRICAL FORMULA FOR THE UNKNOWN COMPOUND IS C7H9O
Explanation:
The empirical formula for the unknown compound can be obtained by following the processes below:
1 . Write out the percentage composition of the individual elements in the compound
C = 75.68 %
H = 8.80 %
O = 15.52 %
2. Divide the percentage composition by the atomic masses of the elements
C = 75 .68 / 12 = 6.3066
H = 8.80 / 1 = 8.8000
O = 15.52 / 16 = 0.9700
3. Divide the individual results by the lowest values
C = 6.3066 / 0.9700 = 6.5016
H = 8.8000 / 0.9700 = 9.0722
O = 0.9700 / 0.9700 = 1
4. Round up the values to the whole number
C = 7
H = 9
O = 1
5 Write out the empirical formula for the compound
C7H90
In conclusion, the empirical formula for the unknown compound is therefore C7H9O
Which correctly lists three characteristics of minerals?
solid, crystal structure, definite chemical composition
organic, crystal structure, definite chemical composition
human-made, solid, organic
crystal structure, definite chemical composition, human-made
Answer:a
Explanation:
The three characteristics of minerals are that they are solid, have definite crystal structure and definite chemical composition.
What are minerals?Minerals are defined as a chemical compound which has a well -defined composition and possesses a specific crystal structure.It occurs naturally in the pure form.
If a compound occurs naturally in different crystal structure then each structure is considered as a different mineral.The chemical composition of a mineral varies depending on the presence of small impurities which are present in small quantities.
Some minerals can have variable proportions of two or more chemical elements which occupy equivalent position in the crystal structure.It may also have variable composition which is split into separate species.
Physical properties of minerals include color,streak, luster,specific gravity and cleavage.
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Consider the three statements below. Which numbered response contains all the statements that are true and no false statements?
I. Hydration is a special case of solvation in which the solvent is water.
II. The oxygen end of water molecules is attracted toward Ca2+ ions.
III. The hydrogen end of water molecules is attracted toward Cl- ions.
a) I, II, and III
b) I and II
c) III
d) I
e) II
Answer:
a) I, II, and III
Explanation:
For the first statement;
Solvation, is the process of attraction and association of molecules of a solvent with molecules or ions of a solute. if the solvent is water, we call this process hydration.
This means the statement is TRUE.
For the second statement;
The negatively-charged side of the water molecules are attracted to positively-charged ions. In the case of water, the oxygen end is the negatively charged side of water. This means the statement is TRUE.
For the third statement;
The positively-charged side of the water molecules are attracted to the negatively-charged chloride ions. In the case of water, the hydrogen end is the positively charged side of water. This means the statement is TRUE.
Going through the options, we can tell that the correct option is option A.
A chemist dissolves 867. mg of pure barium hydroxide in enough water to make up 170. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 degree C.) Be sure your answer has the correct number of significant digits.
Answer: The pH of the solution is 11.2
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in ml
moles of [tex]Ba(OH)_2[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{0.867g}{171g/mol}=0.00507mol[/tex] (1g=1000mg)
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{0.00507\times 1000}{170}[/tex]
[tex]Molarity=0.0298[/tex]
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pOH=-\log [OH^-][/tex]
[tex]Ba(OH)_2\rightarrow Ba^{2+}+2OH^{-}[/tex]
According to stoichiometry,
1 mole of [tex]Ba(OH)_2[/tex] gives 2 mole of [tex]OH^-[/tex]
Thus 0.0298 moles of [tex]Ba(OH)_2[/tex] gives =[tex]\frac{2}{1}\times 0.0298=0.0596[/tex] moles of [tex]OH^-[/tex]
Putting in the values:
[tex]pOH=-\log[0.0596]=2.82[/tex]
[tex]pH+pOH=14[/tex]
[tex]pH=14-2.82[/tex]
[tex]pH=11.2[/tex]
Thus the pH of the solution is 11.2
What causes the electrons to flow through a wire in a lead-acid battery?
Answer:
The potential difference between the cathode and anode are set up from the chemical reaction. Inside the battery electrons are pushed by the chemical reaction toward the positive end creating a potential difference. It is this potential difference that drives the electrons through the wire.
Calculate the theoretical percentage of water for the following hydrates.
(a) manganese(II) monohydrate, MnSO4 H2O
(b) manganese(II) tetrahydrate, MnSO4 4H2O
Answer:
(a) [tex]\% H_2O=10.65\%[/tex]
(b) [tex]\% H_2O=32.2[/tex]
Explanation:
Hello.
For this questions we must consider the ratio of the molar mass of water to hydrated compound molar mass as shown below:
(a) In this case, we can consider that inside the manganese (II) sulfate monohydrate, whose molar mass is 169.02 g/mol, there is one water molecule that has a molar mass of 18 g/mol, for which the theoretical percentage of water is:
[tex]\% H_2O=\frac{18g/mol}{169.0g/mol} *100\%\\\\\% H_2O=10.65\%[/tex]
(b) In this case, we can consider that inside the manganese (II) sulfate tetrahydrate, whose molar mass is 223.1 g/mol, there are four water molecules that have a molar mass of 4*18 g/mol, for which the theoretical percentage of water is:
[tex]\% H_2O=\frac{4*18g/mol}{223.1g/mol} *100\%\\\\\% H_2O=32.27\%[/tex]
Best regards.
How many moles of gaseous boron trifluoride, BF3, are contained in a 4.3410 L bulb at 788.0 K if the pressure is 1.220 atm What is the complete ground state electron configuration for the neon atom
Answer:
n= 0.08186
{He}2s^2 2p^6
Explanation:
PV=nRT
n=PV/RT
n= (1.220 atm)(4.3410 L) / (0.0821 atm*L/mol*K)(788.0 K)
n=0.08186
As for the electron configuration:
Ne:
{He} 2s^2 2p^6
or long hang:
1s^2 2s^2 2p^6
[tex][Ne]=1s^22s^22p^{10}[/tex]
Given:
A gaseous boron trifluoride in a 4.3410 L bulb at 788.0 K, if the pressure is 1.220 atm.Neon atom.To find:
The moles of gaseous boron trifluoride in a container.The electronic configuration of neon in the ground state.1.
The pressure of the gaseous boron trifluoride = P = 1.220 atm
The volume of the gas in bulb = V = 4.3410 L
The moles of the gaseous boron trifluoride = n
The temperature of gaseous boron trifluoride = T = 788.0 K
Using an ideal gas equation:
[tex]PV = nRT\\\\1.220 atm\times 4.3410 L=n\times 0.0821 atm L/mol K\times 788.0 K\\\\n=\frac{1.220 atm\times 4.3410 L}{0.0821 atm L/mol K\times 788.0 K}\\\\n=0.08186 mol[/tex]
The moles of gaseous boron trifluoride is 0.08186 moles.
2.
The atomic number of neon atom = 10
The electronic configuration in the ground state is the most stable arrangement of the electrons in the lowest energy levels.
The ground state electronic configuration of neon is:
[tex][Ne]=1s^22s^22p^{10}[/tex]
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Consider the equilibrium reaction. 4A+B↽−−⇀3C After multiplying the reaction by a factor of 2, what is the new equilibrium equation?
A sample of gold weighs 1.2 oz. The sample is pounded into a thin rectangular sheet with an area of 400. sq. ft. The density of gold is 19.3 grams per cm3. What is the thickness of the foil in centimeters?Given: 28.35 g = 1 oz, 1 ft = 12 inches, 1 inch = 2.54 cm
Answer:
thickness of the gold sheet = 4.74 * 10⁻⁶ cm
Explanation:
mass of gold sample = 1.2 oz,; area of rectangular gold sheet = 400 sq. ft
Converting mass of gold from oz. to g
1 oz. = 28.35 g
mass of gold sample in grams = 1.2 * 28.35 g = 34.02 g
Converting from feet to cm;
1 feet = 12 * 2.54 cm = 30.48 cm
1 sq. ft = (30.48)² = 929.0304 cm²
area of gold in cm² = 400 * 929.0304 cm² = 371612.16 cm²
Since the density of a solid is constant
Density = mass/volume
Volume = mass/density
where volume =area * thickness
therefore, area * thickness =mass/density
thickness = mass/(density * area)
substituting the value; thickness = 34.02 g/(19.3 gcm⁻³ *371612.16 cm²)
thickness of the gold sheet = 4.74 * 10⁻⁶ cm
Perform the following
mathematical operation, and
report the answer to the correct
number of significant figures.
5.446 x 0.14156
Which of the following best identifies where long-range order would be found?
ОООО
in amorphous solids
in crystalline solids
in thermal plasmas
in nonthermal plasmas
Answer:
in crystalline solids
Hope this answers your question, good luck
The crystalline solids represent the best identification where the long-range order should be found.
What are crystalline solids?Crystalline solids refer to the solid where the atoms, molecules should be make the arrangement. The smallest & repeated pattern of this solid should be called as the unit cell. The unit cell should be treated as the bricks in the wall which means it should be homogenous in the nature and repeated
Therefore, The crystalline solids represent the best identification where the long-range order should be found.
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. A compound X, containing C, H, and O was found to have a relative molar mass of 6o
whilst 20.0g of X contained 8.0g of C and 1.33g of H. Calculate the empirical formula
of compound X, and hence determine its molecule formula. show calculation
Answer:
empirical formula = CH2O
molecular formula = C2H4O2
A piece of bismuth with a mass of 22.5 g is submerged in 46.3 cm3 of water in a graduated cylinder. The water level increases to 48.6 cm3. What is the density of indium to the proper number of significant figures
Answer:
[tex]\rho = 9.78\frac{g}{cm^3}[/tex]
Explanation:
Hello,
In this case, in order to compute the density of bismuth we need to apply the formula:
[tex]\rho =\frac{m_{Bi}}{V_{Bi}}[/tex]
Nonetheless, the volume is computed by the difference:
[tex]V_{Bi}=48.6-46.3=2.30cm^3[/tex]
Therefore:
[tex]\rho = \frac{22.5g}{2.30cm^300}\\\\\rho = 9.78\frac{g}{cm^3}[/tex]
Regards.
How many liters of a 1 M NaOH stock solution would you need to make 785 mL of a 215 mM NaOH dilution? (m.w. = 40.00 g/mol) Do not include units in your answer; report your answer in the requested units.
Answer:
0.1688L of the 1M NaOH stock solution
Explanation:
A 215mM = 0.215M solution of NaOH contains 0.215 moles per liter. As you want to prepare 785mL = 0.785L of the 0.215M you will need:
0.785L × ( 0.215mol / L) = 0.1688 moles of NaOH.
These moles of NaOH comes from the 1M stock solution, that means the volume of 1M NaOH solution you need is:
0.1688 moles NaOH × (1L / 1mol) =
0.1688L of the 1M NaOH stock solutionThe volume of the stock solution of 1 M NaOH stock solution needed to make 785 mL of a 215 mM NaOH dilution is 0.169 L
From the question given above, the following data were obtained:
Molarity of stock (M₁) = 1 M
Volume of diluted solution (V₂) = 785 mL = 785 / 1000 = 0.785 L
Molarity of diluted solution (M₂) = 215 mM = 215 / 1000 = 0.215 M
Volume of stock solution needed (V₁) =?
The volume of the stock solution needed can be obtained as follow:
M₁V₁ = M₂V₂1 × V₁ = 0.215 × 0.785
V₁ = 0.169 LTherefore, the volume of the stock solution needed is 0.169 L
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Once the chromatographic column has been prepared, why is it important to allow the level of the liquid in the column to drop the level of the alumina before applying the solution of the compound to be separated?
Answer: Chromatography is a technique which is used for the separation of components present in a mixture into sub-components.
Explanation:
The solvent or liquid used for the separation of the chromatographic mixture should lie below the spot point where the mixture is loaded in an alumina column. This is done to prevent the air bubbles formations, which can lead to poor sanitation. Also this is done to prevent the mixing of the mixture to be separated with the solvent instead of running with the solvent via capillary action.