Answer:
[tex]m=33.9g[/tex]
Explanation:
Hello,
In this case, we can first compute the heat required for such temperature increase, considering the molar heat capacity of water (75.38 J/mol°C):
[tex]Q=nCp \Delta T=3.00mol*75.38\frac{J}{mol\°C} *50.0\°C\\\\Q=11307J[/tex]
Afterwards, the mass of ice that can be melted is computed by:
[tex]Q=n \Delta _{fus}H[/tex]
So we solve for moles with the proper units handling:
[tex]n=\frac{Q}{\Delta _{fus}H} =\frac{11307J}{6010\frac{J}{mol} } =1.88mol[/tex]
Finally, with the molar mass of water we compute the mass:
[tex]m=1.88mol*\frac{18g}{1mol}\\ \\m=33.9g[/tex]
Best regards.
mass=33.9g
Given:
n= 3.00 mol
Δfus H° = 6.01 kJ/mol H₂O(s)
Enthalpy of fusion is the change in its enthalpy resulting from providing energy, typically heat, to a specific quantity of the substance to change its state from a solid to a liquid, at constant pressure.
In this case, we can first compute the heat required for such temperature increase, considering the molar heat capacity of water (75.38 J/mol°C):
[tex]Q=nC_P[/tex]ΔT
[tex]Q=3.00\text{mol}*75.38\frac{J}{mol^oC} *50.0^oC\\\\Q=11307J[/tex]
Now, the mass of ice that can be melted is given by:
Q=nΔfus H°
So we solve for moles with the proper units handling:
n= Q/ Δfus H°
[tex]n=\frac{11307 J}{6010\frac{J}{mol} } =1.88 mol[/tex]
On substituting the moles with the molar mass of water we get:
[tex]m=1.88 mol*\frac{18 g}{1mol}\\\\m=33.9g[/tex]
The mass of ice is 33.9g.
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The molecular weight of table salt, NaCl, is 58.5 g/mol. A tablespoon of salt weighs 6.37 grams. Calculate the number of moles of salt in one tablespoon.
Finally, solve (remember significant figures):
Answer:
0.109 mol/tablespoon
Explanation:
6.37 g/ 58.5 mol = 0.10888888 mol (0.109 significantly)
Answer:
A: 0.109
Explanation:
Edge 2020
Which of the following atoms would have the longest de Broglie wavelength, if all have the same velocity?
A) Li
B) Na
C) Fe
D) Pb
E) Not possible to tell with given information
Answer:
Li
Explanation:
The phenomenon of wave particle duality was well established by Louis deBroglie. The wavelength associated with matter waves was related to its mass and velocity as shown below;
λ= h/mv
Where;
λ= wavelength of matter waves
m= mass of the particle
v= velocity of the particle
This implies that if the velocities of all particles are the same, the wavelength of matter waves will now depend on the mass of the particle. Hence; the wavelength of a matter wave associated with a particle is inversely proportional to the magnitude of the particle's linear momentum. The longest wavelength will then be obtained from the smallest mass of matter. Hence lithium which has the smallest mass will exhibit the longest DeBroglie wavelength
The atom that have the longest de Broglie wavelength is ; ( A ) Li
Wave particle duality is a phenomenon by de Broglie. that shows that The wavelength associated with matter waves is related to its mass and velocity .
Wave particle duality is represented as ; λ = h / mv
λ= wavelength of matter waves
m= mass of the particle
v= velocity of the particle
Given that the elements have the same velocity the atom that would have the longest de Broglie wavelength is Li
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The compound barium nitrate is a strong electrolyte. Write the transformation that occurs when solid barium nitrate dissolves in water.
Answer:
Ba(NO₃)₂(s) → Ba²⁺ + 2NO₃⁻
Explanation:
A strong electrolyte is a salt (A compound that has an anion and a cation and are neutral) that, in water, dissociates completely in its ions.
In Barium nitrate, Ba(NO₃)₂, the cation is Ba²⁺ (Alkaline earth metal), and the anion is the nitrate ion, NO₃⁻.
Thus, when Ba(NO₃)₂ (s) is dissolved in water, its transformation is:
Ba(NO₃)₂(s) → Ba²⁺ + 2NO₃⁻When solid barium nitrate (Ba(NO₃)₂) dissolves in water, it undergoes a dissociation process where the compound breaks apart into its constituent ions.
Dissociation refers to the process in which a compound breaks apart into its constituent ions when dissolved in a solvent, typically water. In this process, the chemical bonds within the compound are disrupted, resulting in the separation of positive and negative ions.
The dissociation occurs due to the interaction between the solute particles and the solvent molecules, leading to the formation of hydrated ions.
The transformation can be represented as follows:
Ba(NO₃)₂(s) → Ba²⁺(aq) + 2NO₃⁻(aq)
In this process, the barium nitrate compound dissociates into barium ions (Ba²⁺) and nitrate ions (NO₃⁻) in the aqueous solution. The resulting ions are free to move and conduct electricity, indicating that barium nitrate is a strong electrolyte when dissolved in water.
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Write the empirical formula
Answer:
See the explanation and answer below.
Explanation:
In chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound. The formula gives the proportions of the elements present in a compound but not the actual arrangement of atoms.
[tex]\mathrm{Molecular \:Formula}\quad \quad |\quad \quad \mathrm{Empirical \:Formula}[/tex]
[tex]1.\:\:\:NH_4OH\quad | \quad H_5NO[/tex] (Ammonium hydroxide)
[tex]2.\:\:\:Fe(OH)_3\quad |\quad FeH_3O_3[/tex] (Iron(III) hydroxide)
[tex]3.\:\:\:NH_4C_2H_3O_2\quad |\quad C_2H_7NO_2[/tex] (Ammonium acetate)
[tex]4.\:\:\:Fe(C_2H_3O_2)_3\quad |\quad C_6H_9FeO_6[/tex] (Iron(III) Acetate)
I hate chemistry but best regards!
Draw a structural formula of an alkene or alkenes (if more than one) that undergo acid-catalyzed hydration and without re-arrangement give 2-butanol as the major product.
Answer:
See explanation
Explanation:
Hydration of alkenes is a common reaction in organic chemistry. Hydration is simply the addition of water to an alkene. This is an acid catalysed reaction as we can see from the mechanism attached.
Recall that our task is to carry out the synthesis of 2-butanol using an alkene starting material in which there will be no rearrangement of the intermediate carbocation. If we start with the compound shown in the image (but-2-ene), the first step is the formation of the secondary carbocation. This is followed by the addition of water. Subsequently, the added water is deprotonated by another water molecule to yield 2-butanol and the acid catalyst. All these steps have been clearly outlined in the image attached.
Calculate the mass of a body
Whose volume is
Is 2cm3 and
density is 520cm3
Answer:
The answer is
1040gExplanation:
Density = mass / volume
mass = density × volume
volume = 2cm³
density = 520g/cm³
mass = 2 × 520
= 1040g
Hope this helps you
: Starting with 0.3500 mol CO(g) and 0.05500 mol COCl2(g) in a 3.050-L flask at 668 K, how many moles of Cl2(g) will be present at equilibrium
Answer:
The number of moles of Cl₂ present at equilibrium is 3.94x10⁻⁴ moles.
Explanation:
The reaction is:
CO(g) + Cl₂(g) ⇄ COCl₂(g)
The equilibrium constant of the above reaction is:
K = 1.2x10³
To find the moles of Cl₂ present at equilibrium, let's evaluate the reverse reaction:
COCl₂(g) ⇄ CO(g) + Cl₂(g)
The equilibrium constant for the reverse reaction is:
[tex] K_{r} = \frac{1}{1.2 \cdot 10^{3}} = 8.3 \cdot 10^{-4} [/tex]
Now, we need to calculate the concentration of CO and COCl₂:
[tex] C_{CO} = \frac{\eta_{CO}}{V} = \frac{0.3500 moles}{3.050 L} = 0.115 M [/tex]
[tex] C_{COCl_{2}} = \frac{\eta_{COCl_{2}}}{V} = \frac{0.05500 moles}{3.050 L} = 0.018 M [/tex]
Now, from the reaction we have:
COCl₂(g) ⇄ CO(g) + Cl₂(g)
0.018 - x 0.115+x x
The concentration of Cl₂ is:
[tex] K_{r} = \frac{[CO][Cl_{2}]}{[COCl_{2}]} [/tex]
[tex] 8.3 \cdot 10^{-4} = \frac{(0.115 + x)(x)}{0.018 - x} [/tex]
[tex] 8.3 \cdot 10^{-4}*(0.018 - x) - (0.115 + x)(x) = 0 [/tex]
By solving the above equation for x we have:
x = 1.29x10⁻⁴ M = [Cl₂]
Finally, the number of moles of Cl₂ present at equilibrium is:
[tex] \eta_{Cl_{2}} = C_{Cl_{2}}*V = 1.29 \cdot 10^{-4} mol/L*3.050 L = 3.94 \cdot 10^{-4} moles [/tex]
Therefore, the number of moles of Cl₂ present at equilibrium is 3.94x10⁻⁴ moles.
I hope it helps you!
What is the atomic mass of OsO4
Answer:
254.23 g/mol
Explanation:
Atomic mass for Osmium tetroxide would be 254.23 g/ml
Answer:254.2276
Explanation:
what phrase best describes the arrangement of these electron groups around the central nitrogen atom
Answer:
the electron groups around the central nitrogen atom is trigonal planar
Explanation:
An electron group is defined as a bond (single or multiple) or/and a non-bonding electron pair around the central atom. The central nitrogen (N) atom in NO3- has three (3) electron groups (three bonds to three oxygen, O atoms).
Three electron groups around a central atom are best arranged in a trigonal planer arrangement to minimize repulsions between the bonding and/or non-bonding electrons. Therefore, the arrangement of the electron groups is trigonal planer or planer trigonal.
Calculate the number of moles of C2H6 in 3.97×1023 molecules of C2H6.
3.97×1023 molecules C2H6 1 mol C2H6
------------------------------------------ x ------------------------------------ = 0.66 mol C2H6
6.022 x 1023 molec. C2H6
A transition in the balmer series for hydrogen has an observed wavelength of 434 nm. Use the Rydberg equation below to find the energy level that the transition originated. Transitions in the Balmer series all terminate n=2.
Delta E= -2.178 x10-18J ( 1/n2Final - 1/n2Initial )
The number is 5.
What is the energy of this transition in units of kJ/mole? ( hint: the anser is NOT 4.58x10-22kJ/mole or -4.58x10-22kJ/mole)
Answer:
i. n = 5
ii. ΔE = 7.61 × [tex]10^{-46}[/tex] KJ/mole
Explanation:
1. ΔE = (1/λ) = -2.178 × [tex]10^{-18}[/tex]([tex]\frac{1}{n^{2}_{final} }[/tex] - [tex]\frac{1}{n^{2}_{initial} }[/tex])
(1/434 × [tex]10^{-9}[/tex]) = -2.178 × [tex]10^{-18}[/tex] ([tex]\frac{n^{2}_{initial} - n^{2}_{final} }{n^{2}_{final} n^{2}_{initial} }[/tex])
⇒ 434 × [tex]10^{-9}[/tex] = (1/-2.178 × [tex]10^{-18}[/tex])[tex]\frac{n^{2}_{final} *n^{2}_{initial} }{n^{2}_{initial} - n^{2}_{final} }[/tex]
But, [tex]n_{final}[/tex] = 2
434 × [tex]10^{-9}[/tex] = (1/2.178 × [tex]10^{-18}[/tex])[tex]\frac{2^{2} n^{2}_{initial} }{n^{2}_{initial} - 2^{2} }[/tex]
434 × [tex]10^{-9}[/tex] × 2.178 × [tex]10^{-18}[/tex] = [tex](\frac{4n^{2}_{initial} }{n^{2}_{initial} - 4 })[/tex]
⇒ [tex]n_{initial}[/tex] = 5
Therefore, the initial energy level where transition occurred is from 5.
2. ΔE = hf
= (hc) ÷ λ
= (6.626 × 10−34 × 3.0 × [tex]10^{8}[/tex] ) ÷ (434 × [tex]10^{-9}[/tex])
= (1.9878 × [tex]10^{-25}[/tex]) ÷ (434 × [tex]10^{-9}[/tex])
= 4.58 × [tex]10^{-19}[/tex] J
= 4.58 × [tex]10^{-22}[/tex] KJ
But 1 mole = 6.02×[tex]10^{23}[/tex], then;
energy in KJ/mole = (4.58 × [tex]10^{-22}[/tex] KJ) ÷ (6.02×[tex]10^{23}[/tex])
= 7.61 × [tex]10^{-46}[/tex] KJ/mole
The initial energy level is 5 and the energy of this transition in units of kJ/mole is 7.57 * 10^-43 kJ/mole
We must first calculate ΔE as follows;
ΔE = hc/λ
h = Plank's constant = 6.6 * 10^-34 Js
c = speed of light = 3 * 10^8 m/s
λ = wavelength = 434 * 10^-9
ΔE = 6.6 * 10^-34 * 3 * 10^8/434 * 10^-9
ΔE = 0.0456 * 10^-17 J
ΔE = [tex]ΔE = -2.178 x10^-18 (\frac{1}{n^2final} - \frac{1}{n^2initial}) \\ΔE = -2.178 x10^-18 (\frac{1}{2^2} - \frac{1}{n^2initial} )\\\\4.56 * 10^-19/2.178 x10^-18 = (\frac{1}{2^2} - \frac{1}{n^2initial})\\0.210 = (\frac{1}{2^2} - \frac{1}{n^2initial})\\\frac{1}{n^2initial} = 0.25 - 0.210\\\frac{1}{n^2final} = 0.04\\n = (\sqrt{(0.04)^-1} \\n = 5[/tex]
Energy of this transition in units of kJ/mole = 4.56 * 10^-19/ 6.02 * 10^23
= 7.57 * 10^-43 kJ/mole
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Q3. Which of the following objects are chiral and which are achiral? a
club b. teacup c. football d. corkscrew e. tennis racket f. shoe g. portrai
pencil (8 marks)
Q4. Write a structure for each of the compounds listed. Explain why th
name given is incorrect, and give a correct name in each case (20 mai
a. l-methylbutane
b. 1.1,3-trimethylhexane
c. 5-octyne
d. 2-ethyl-1-propanol
e. 2.2-dimethyl-3-butanol
Submit via aduwiejuah a uds.edu.gh and deadline for submission is
July, 2020 at 11:00 AM.
Answer:
See explanation
Explanation:
In this question, we have to follow the IUPAC rules. Lets analyze each compound:
a. 1-methylbutane
In this compound we have a chain of 5 carbons, so the correct name is Pentane.
b. 1,1,3-trimethylhexane
In this compound, we longest chain is made of 7 carbons, so, we have to use the name "heptane". Carbon one would be the closet one to the methyl group, so the correct name is 2,4-dimethylheptane.
c. 5-octyne
In this case, carbon 1 would be the closet one to the triplet bond. With this in mind, the correct name is oct-3-yne.
d. 2-ethyl-1-propanol
In this compound, we longest chain is made of 4 carbons, so, we have to use the name "butane". Carbon one would be the carbon with the "OH" group, so the correct name is 2-methylbutan-1-ol.
e. 2.2-dimethyl-3-butanol
In this case, carbon 1 would be the closet one to the "OH". With this in mind, the correct name is 3,3-dimethylbutan-2-ol.
See figure 1
I hope it helps!
Which of the following describes green design?
A. Materials that will fail in a predictable and safe way
B. The use of new engineering technologies in building construction
c. Building structures made of composite materials to make them
safer
D. Materials and design techniques that reduce the negative
environmental impact of a structure
Answer: materials and design Techniques that reduce the negative environmental impact of a structure
Explanation:
1. If a carbohydrate, like xylulose, has five carbon atoms and a carbonyl group on the second carbon, it is called a(n):_______.
2. Glyceraldehyde is an example of a(n):_____, because it has three carbon atoms.
3. A monosaccharide is a(n):_______ if the carbonyl group is on the end of the carbon chain.
4. Any carbohydrate with the carbonyl group on the second carbon is a(n):_______.
5. The most common carbohydrate, , has six carbon atoms.
6. With the carbonyl group on the end of a six-carbon chain, the carbohydrate would be classified as a(n):_________.
Answer:
Following are the answer to this question:
Explanation:
The answer are:
1) ketopentose
2) Triose
3) Aldose
4) Ketose
5) Glucose
6) Aldohexose
The pentose has 2-position contain a personal ketone group. The triose is a monosaccharide or simple sugar that contains three atoms of carbon. The Aldose and ketose are simple carbohydrates, both also called monosaccharides. In aldose, it has a functional group of aldehydes within its structure. The ketose sugars have workable ketone groups. Stereoisomerism has been found in aldose sugars that contain more than three carbon atoms. Glucose is also one of the main molecules which function as plant and animal energy sources. It's also derived from plant sap and seems to be present in the bloodstream of humans, that's why it is called "blood sugar." The aldohexose is a hexose is a group of aldehydes on one end, it has a total of 16 possible aldohexose stereoisomers in four chiral centers.Using the thermodynamic information , calculate the standard reaction entropy of the following chemical reaction: Round your answer to zero decimal places.
2Al(s)+ Fe2O3(s) → Al2O3(s)+ 2Fe(s)
Answer:
The answer is "−847 J/K".
Explanation:
The given expression is:
2Al(s)+ Fe2O3(s) → Al2O3(s)+ 2Fe(s)
Δ[tex]H^{\circ}_{rxn}=[/tex] ∑(Δ[tex]H^{\circ}_{products}-H^{\circ}_{reactants}[/tex])
by the above definition Δ[tex]H^{\circ}_{element}= 0\cdot KJ \cdot Mol^{-1}[/tex] For Such a Component under standard conditions from its standard state, that also applies here. But, we start taking the overview and follow the conventions of signing:
[tex]\to (-1669)-(-822) \frac{KJ}{mol}\\\\\to (-1669+822) \frac{KJ}{mol}\\\\\to -847\frac{KJ}{mol}\\\\[/tex]
Δ[tex]H^{\circ}_{rxn}=[/tex] -847 [tex]\frac{KJ}{mol} \ mol^{-1} \texttt{ we mean \mole of Reaction as written....}\\[/tex]
Given the specific heat for aluminum is 0.900 J/g.°C, how much heat is released when a 3.8 g sample
of Al cools from 450.0°C to 25°C?
A. 1.5 kJ
B. 54 J
C. 60J
D. 1.7 kJ
E. 86 J
Answer:
Q = 1.5 kJ
Explanation:
It is given that,
The specific heat for aluminum is 0.900 J/g°C
Mass of sample, m = 3.8 g
Initial temperature, [tex]T_i=450^{\circ} C[/tex]
Final temperature, [tex]T_f=25^{\circ} C[/tex]
We need to find the heat released. The amount of heat released is given by the formula:
[tex]Q=mc\Delta T\\\\Q=mc(T_f-T_i)\\\\Q=3.8\times 0.9\times (25-450)\\\\Q=1453.5\ J\\\\Q=1.45\ kJ[/tex]
or
[tex]Q=1.5\ kJ[/tex]
So, the correct option is (A) i.e. 1.5 kJ.
Calculate the combustion of gaseous dimethyl ether CH 3 OCH 3 (g)+3O 2 (g) 2CO 2 (g)+3H 2 O(l) using standard molar enthalpies of formation Molecule AH H l ^ 0 (k)/mol) CH 3 OCH 3 (g) - 184.1
Answer:
[tex]\Delta _cH=-1328.3kJ/mol[/tex]
Explanation:
Helllo,
In this case, for the given chemical reaction in gaseous state:
[tex]CH_3OCH_3+3O_2\rightarrow 2CO_2+3H_2O[/tex]
We comoute the combustion enthalpy as the reaction enthalpy for one mole of fuel (dimethyl ether) considering the formation enthalpy of each given substance and whether they are reactants (subtracting) or products (adding), therefore we write:
[tex]\Delta _cH=2*\Delta _fH_{CO_2}+3*\Delta _fH_{H_2O}-\Delta _fH_{CH_3OCH_3}-3*\Delta _fH_{O_2}[/tex]
Whereas the formation enthalpies for carbon dioxide, water, dimethyl ether and oxygen are -393.5, -241.8, -184.1 and 0 kJ/mol respectively, thereby, the combustion enthalpy turns out:
[tex]\Delta _cH=2(-393.5)+3*(-241.8)-(-184.1)-3(0)\\\\\Delta _cH=-1328.3kJ/mol[/tex]
Notice that enthalpy of formation of oxygen is zero since forming an element has no chemical sense, it just exists as it has been early demonstrated.
Regards.
Chemistry question. Image attached.
Answer:
The balanced equation is given below: C2H6O + 3O2 —> 2CO2 + 3H2O
The coefficients are: 1, 3, 2, 3
Explanation:
C2H6O + O2 —> CO2 + H2O
The above equation can be balance as follow:
There are 2 atoms of C on the left side and 1 atom on the right side. It can be balance by putting 2 in front of CO2 as shown below:
C2H6O + O2 —> 2CO2 + H2O
There are 6 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 3 in front of H2O as shown below:
C2H6O + O2 —> 2CO2 + 3H2O
There are a total of 3 atoms of O on the left side and a total of 7 atoms on the right side. It can be balance by putting 3 in front of O2 as shown below:
C2H6O + 3O2 —> 2CO2 + 3H2O
Now the equation is balanced.
The coefficients are: 1, 3, 2, 3.
Answer:
The balanced equation is given below: C2H6O + 3O2 —> 2CO2 + 3H2O
The coefficients are: 1, 3, 2, 3
Explanation:
C2H6O + O2 —> CO2 + H2O
The above equation can be balance as follow:
There are 2 atoms of C on the left side and 1 atom on the right side. It can be balance by putting 2 in front of CO2 as shown below:
C2H6O + O2 —> 2CO2 + H2O
There are 6 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 3 in front of H2O as shown below:
C2H6O + O2 —> 2CO2 + 3H2O
There are a total of 3 atoms of O on the left side and a total of 7 atoms on the right side. It can be balance by putting 3 in front of O2 as shown below:
C2H6O + 3O2 —> 2CO2 + 3H2O
Now the equation is balanced.
The coefficients are: 1, 3, 2, 3.
Explanation:
Compound X has the formula C7H14. X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form 3-methylhexane. Treatment of X with ozone follwed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O). What is the structure of X?
Answer:
3-methylenehexane
Explanation:
In this case, we have two clues.
1) The hydrogenation reaction
2) The ozonolysis reaction
See figure 1.
With this in mind, lets analyze each clue. In the first reaction, we know that only 1 molecule of [tex]H_2[/tex] is added to the unknown molecule. This indicates that we only have 1 double bond in the molecule. Now, the next question is where is placed the double bond?
To answer this question, we have to use the second clue. In the ozonolysis reaction, a double bond is broken and is replaced with a carbonyl group. If, formaldehyde is formed the double bond is formed with a primary carbon. The primary carbons in the structure (given in the first reaction: 3-methylhexane) are carbons 1, 6, and 7. So, the double bond can be placed between carbons:
a) 6 and 5
b) 7 and 3
c) 1 and 2
To decide which one is the position of the double bond we have to keep in mind the second product of the ozonolysis reaction a ketone. With this in mind, the carbon bonded to the primary one (deduced by the formaldehyde) it has to be a tertiary carbon. The only option that has a primary carbon bonded to tertiary carbon is b). (See figure 2)
Finally, with this in mind the structure is 3-methylenehexane. To be sure, we can check the formula for the compound, [tex]C_7H_1_4[/tex] and the reactions. (See figure 3)
I hope it helps!
How many valence electrons are in the electron dot structures for the elements in group 3A(13)?
Answer:
here, as we have known the elements of group 3A(13) such as aluminium , boron has three valance electron and in perodic table the elements are kept with similar proterties in same place so, their valance electron is 3.
hope it helps...
The number of valence electrons are in the electron dot structures for the elements in group 3A(13) is three.
What are Groups in the Periodic Table?The periodic table is organized into groups (vertical columns), periods (horizontal rows), and families (groups of elements that are similar). Elements in the same group have the same number of valence electrons.
Groups are the columns of the periodic table, and periods are the rows. There are 18 groups, and there are 7 periods plus the lanthanides and actinides.
There are two different numbering systems that are commonly used to designate groups, and you should be familiar with both.
The traditional system used in the United States involves the use of the letters A and B. The first two groups are 1A and 2A, while the last six groups are 3A through 8A. The middle groups use B in their titles.
Therefore, The number of valence electrons are in the electron dot structures for the elements in group 3A(13) is three.
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Where would you find the following symbol on a diagram of a water molecule: δ+ ?
Answer:
On the 2 hydrogen atoms.
Explanation:
δ+ indicates the atom has a lower electronegativity than the other atom it is bonded with. This only exist in polar covalent bonds, where the 2 atoms have different electronegativity values. When they have different electronegativity values, the one with higher electronegativity has a higher tendency to "pull" the shared electrons towards itself, they have a δ- symbol.
Back to H2O, since the electronegativity of elements increases from left to right horizontally and upwards vertically in the periodic table (except for noble gases, they are unreactive. Note that fluorine has the highest electronegativity), O atom has a higher electronegativity than hydrogen (hydrogen sits at the centre top of the table). hence, we can find δ+ on the hydrogen atoms.
Which substance is the oxidizing agent in the following reaction? 2H2 + O2 -> 2H2O
Answer:
O₂
Explanation:
When we create H₂O, the electrons tend to be shared by oxygen. The hydrogen bonds with the oxygen covalently, but the electrons tend to stay with the oxygen longer rather than near the hydrogens.
Click the "draw structure" button to launch the drawing utility. Draw the product of the reaction of propanal with lithium aluminum hydride, followed by water.
Answer:
Product: propan-1-ol
Explanation:
IIn this case, we have to remember that [tex]LiAlH_4[/tex] is a reduction agent. So, this is a reduction reaction. The [tex]LiAlH_4[/tex] has the ability to produce hydride ions [tex]H^-[/tex]. This ion can attack the carbonyl group generating a negative charge in the oxygen. In the next step, the negative charge in the oxygen can attack a water molecule to protonate the molecule and produce propan-1-ol.
See figure 1
I hope it helps!
A constant volume and mass of helium gas at 77°C is heated so that the pressure of the gas doubles. What is the new temperature of the gas in Celsius degrees?
Answer:
427°C .
Explanation:
Step 1:
Data obtained from the question. This include the following:
Initial temperature (T1) = 77°C
Initial pressure (P1) = P
Final pressure (P2) = 2P
Final temperature (T2) =?
Step 2:
Conversion of celsius temperature to Kelvin temperature.
This is illustrated below:
T(K) = T (°C) + 273
Initial temperature (T1) = 77°C
Initial temperature (T1) = 77°C+ 273 = 350K
Step 3:
Determination of the new temperature. The new temperature can be obtained as follow:
P1/T1 = P2/T2
P/350 = 2P/T2
Cross multiply
P x T2 = 350 x 2P
Divide both side by P
T2 = (350 x 2P ) / P
T2 = 700K
Step 4:
Conversion of Kelvin temperature to celsius temperature.
This can be obtained as follow:
T(°C) = T(K) – 273
T(K) = 700K
T(°C) = 700 – 273
T(°C) = 427°C
Therefore, the new temperature of the gas is 427°C
Which physical method can be used for obtaining a sample of salt from a small beaker of salt water?
boiling
freezing
chromatography
sorting
Answer:
a. boiling
Explanation:
If a neutral acid donates a proton, the conjugate base will have a charge of _______. - Type both an integer and a sign for your answer.
Answer:
-1
Explanation:
If you donate a proton (positive charge) then the result will leave a negative charge. (a negative and positive charge result In a neutral charge)
The answer is -1
Now if i have an acid such as H2SO4. Recall that the neutral acid is dibasic as you cam see from the formula of the acid, the acid can give out a proton as follows;
[tex]H2SO4 ------> H^+ + HSO4^-[/tex]
We can see that the conjugate base (HSO4-) has a charge of -1 as written in the answer.
The same also happens for a monobasic acid and so on.
https://brainly.com/question/12883745
Calculate the pH of a 0.0255 M solution of ammonium bromide (NH4Br). The Kb of ammonia is 1.76 x 10-5
Answer:
5.42
Explanation:
Step 1: Consider the dissociation of NH₄Br
NH₄Br(aq) ⇒ NH₄⁺(aq) + Br⁻(aq)
Br⁻ is the conjugate base of HBr, a strong acid, so it doesn´t react with water. NH₄⁺ is the conjugate acid of NH₃, so it does react with water.
Step 2: Consider the acid reaction of NH₄⁺
NH₄⁺(aq) + H₂O(l) ⇄ NH₃(aq) + H₃O⁺(aq)
Step 3: calculate the acid dissociation constant for NH₄⁺
We will use the following expression.
[tex]K_a \times K_b = K_w\\K_a = \frac{K_w}{K_b} = \frac{1.00 \times 10^{-14} }{1.76 \times 10^{-5}} = 5.68 \times 10^{-10}[/tex]
Step 4: Calculate the concentration of H₃O⁺
We will use the following expression.
[tex][H_3O^{+} ]= \sqrt{K_a \times C_a } = \sqrt{5.68 \times 10^{-10} \times 0.0255 } = 3.81 \times 10^{-6}M[/tex]
Step 5: Calculate the pH
We will use the following expression.
[tex]pH = -log [H_3O^{+} ] = -log (3.81 \times 10^{-6}) = 5.42[/tex]
The pH of 0.0255 M solution should be 5.42.
Calculation of the pH of 0.0255 M solution:Since we know that
ka * kb = kw
So,
ka = kw/kb
= 1.00*10^-14 / 1.76*10^-5
= 5.68*10^-10
Now the concentration of H3O should be
= √ka * Ca
= √5.68*10^-10 * 0.0255
= 3.81*10^-6M
Now the pH value should be
= -log(H3O+)
= -log(3.81*10^-6)
= 5.42
hence, The pH of 0.0255 M solution should be 5.42.
Learn more about pH here: https://brainly.com/question/23506014
Discuss the contrary aspect of proton NMR and C-13 NMR by elucidating the structure of 2 chloro pentanal?
Answer:
See explanation
Explanation:
1H NMR
In the 2-chloro-pentanal we have 4 different types of hydrogens. Therefore, we will have 4 different signals. (See figure 1)
Red hydrogen
For the red hydrogens we have only 1 neighbor. So, if we follow the n+1 rule we can calculate the multiplicity of this hydrogen. In this case a doublet.
Blue hydrogens
In this case, we have 3 neighbors (one in the right, two in the left). Therefore we will have a quartet.
Purple hydrogens
For these hydrogens, we have also will have a quartet, because we have 3 neighbors (one in the right, two in the left).
Green hydrogens
In the green hydrogen,s we have 5 neighbors (2 in the right 3 in the left). Therefore a sextet would be produced.
Orange hydrogens
Finally, in these hydrogens, we have 2 neighbors. Therefore a triplet is expected.
13C NMR
For the 13C NMR, we have again 4 different kinds of carbons. Therefore we will have 4 signals. The most deshielded carbon, in this case, is the red one (see figure 2), so this carbon would be on the left side (around 190). Then the next deshield carbon is the blue one, due to the "Cl" atom placed on this carbon.
I hope it helps!
The thermochemical equation is for the reaction of hydrogen bromide gas to form hydrogen gas and bromine liquid. 2HBr(g) = H 2 (g)+ Br 2 (l) 72.6 kJ How many grams of HBr (g) would be made to react if 11.4 energy were provided?
Answer:
the mass of HBr that would react is 25.41 g of HBr
Explanation:
attached is the calculations.
Read the following passage and find the two errors. Then, choose the answer that corrects the errors.
pH is a measure of the concentration of OH ions in a solution of an acid or base. The pH scale plots the concentration of solutions in a range from 0-16.
O pH is a measure of the concentration of Hions in a solution of an acid or base. The pH plots the concentration of solutions in a range from 0-14.
O pH is a measure of the concentration of H* ions in a solution of an acid or base. The basic scale plots the concentration of solutions in a range from 0-16.
O pH is a measure of the concentration of OH" ions in a solution of water. The pH scale plots the concentration of solutions in a range from 0-12
O pH is a measure of the concentration of OH" ions in a solution of an acid or base. The acid scale plots the concentration of solutions in a range from 0-
16
Answer:
pH is a measure of the concentration of H+ ions in a solution of an acid or base. The pH plots the concentration of solutions in a range from 0–14.
Explanation:
The pH is a measure of the hydrogen ion(H^+) concentration in an acid or base. It can be obtained mathematically by the formula:
pH = —Log [H^+]
The pH scale ranges from 0 to 14
Answer:
it really is A
Explanation:
just got wrong answer because i put 16 and clearly b and c makes no sence : )