Answer:
Explanation:
Given that;
The chemical equation for the reaction is:
[tex]\text {4NH}_3(g) +\text {5O}_2(g) }[/tex] ↔ [tex]\text {4NO}(g) +\text {6H}_2O}(g) }[/tex]
a). [tex]\Delta H^0 = \sum \Delta H^0_{reactant \ bonds \ broken} + \sum \Delta H^0_{product \ bonds \ formed}[/tex]
Using average bond energies;
For Bonds broken, we have:
4 × 3 N - H = 12 mol × 391 kJ/mol = 4692 kJ
5 × O = O = 5 mol × 498 kJ/mol = 2490 kJ
[tex]\mathbf{ \sum \Delta H^0_{reactant \ bonds \ broken} }[/tex] = 7182 kJ
For Bonds formed, we have:
4 × N = O = 4 mol × - 607 kJ/mol = -2428 kJ
6 × 2 O - H = 12 mol × - 467 kJ/mol = - 5604 kJ
[tex]\mathbf{ \sum \Delta H^0_{product \ bonds \ formed} }[/tex] = - 8032 kJ
Therefore;
[tex]\mathbf{ \Delta H^o = 7182 kJ + (- 8032 \ kJ)}[/tex]
[tex]\mathbf{ \Delta H^o =-850 \ kJ}[/tex]
b) Using Standard heats of formation;
[tex]\Delta H^0 = \sum m \Delta H^0_f (products) = \sum n \Delta H^0_f (reactants)[/tex]
[tex]\Delta H^0 = [ 4 \ mol \times \Delta H^0_f \ (NO(g)) + 6\ mol \times \Delta H^0_f(H_2O)] - [ 4 \ mol \times \Delta H^0_f \ (NH_3(g)) + 5 \ mol \times \Delta H^0_f \ (O_2)][/tex]
[tex]\Delta H^0 = [ 4 \ mol \times90.29 \ kJ/mol + 6\ mol \times -241.826 \ kJ/mol - [ 4 \ mol \times-45.9 \ kJ/mol + 5 \ mol \times 0][/tex]
[tex]\mathbf{\Delta H^0 = -906.196 \ kJ}[/tex]
c) The value of ΔH^o, calculated using average bond energies, is only considered to be an estimate of the standard enthalpy change for the reaction because there is a premise in the calculation that all the bonds broken in the reactant and all bonds are formed in products. Meanwhile, only little bonds are broken, and only little bonds are formed during the reaction.
Determine the correct amino acid sequence of a heptapeptide (a small peptide containing seven amino acids) on the basis of the following data. Note: when the amino acid sequence is not given, a comma separates the amino acids.
(i) Amino acid composition: (Ala, Arg, Leu, Lys, Phe and 2Val). It means that this heptapeptide contains one Ala, one Arg, one Leu, one Lys, one Phe and two Val.
(ii) N-terminal analysis of the heptapeptide: Leu
(iii) Trypsin digestion (cleavage) of the heptapeptide yielded two fragments: (Lys, Phe, Val, Val) and (Ala, Arg, Leu)
(iv) Carboxypeptidase A digestion of the heptapeptide: no digestion
(v) Chymotrypsin digestion of the heptapeptide produced two fragments: (Ala, Arg, Leu, Phe) and (Lys, Val, Val)
The correct amino acid sequence of this heptapeptide from N-terminal to C-terminal is:________.
a. Leu-Ala-Arg-Phe-Val-Val-Lys
b. Leu-Ala-Arg-Val-Phe-Val-Lys
c. Leu-Ala-Phe-Arg-Val-Val-Lys
d. Arg-Ala-Lys-Val-Phe-Val-Leu
e. Leu-Ala-Lys-Val-Phe-Val-Arg
Answer:
a. Leu-Ala-Arg-Phe-Val-Val-Lys .
Explanation:
Hello.
In this case, considering the given data, we notice that the amino acid has a N-terminal Leu, that is why we first discard d. Moreover, considering the data (iii) and (v) we can infer that there are going to be two fragments by which it is possible to reason the proper sequence:
(iii): the amino acid has one section composed by Lys-Phe-Val-Val and another one by Ala, Arg, Leu that is why e is also discarded.
(v): the other two fragments are Ala, Arg, Leu, Phe, that is why b is discarded.
(iii) and (v): given the aforementioned fragments, we can combine them and therefore discard c, that is why the correct sequence is:
a. Leu-Ala-Arg-Phe-Val-Val-Lys .
Best regards.
How does water shape earth surfaces
Answer:
jeanne I have to be at work at school
Please answer 11 to 13 to receive 10 Brainly points. Please read the bullet points to under the questions. And check the molecular formula image.
Answer:
11 yes
12 H2O( water molecules)
13 3H2O( water molecules)
Explanation:
Sry, my phone's a potato, so I didn't read it properly, so I'm not sure about the question 11.
11-yes, they stay together, but they release 3 molecules of OH an H.
12- here it talks about what will happen with OH and H: they will be H2O (water molecules).
13- and here we end it with the informations that we got: 3 fatty acids+ glycerol---> fat+ 3H2O( the 3 H and 3 OH)
Which of the following is true about metallic bonds?
o A. Electrons are strongly attracted to the nucleus.
B. Electrons of metals are always shared.
C. Electrons are highly stable.
O
D. Electrons are delocalized.
Answer:
D: electrones are delocalized
The metallic bond has been characterized with the de localization of the electrons. Thus, option D is correct.
Metallic bond has been the type of inter-molecular force that has been found in between the metal atoms.
Metals atom have been capable of donating the electrons in order to become stable. In the metallic bond, there has been the de-localization of the electrons of p orbitals that has been resulted in the electron cloud for the formation of the metallic bond.
Thus, the metallic bond has been characterized with the de localization of the electrons. Thus, option D is correct.
For more information about the metallic bond, refer to the link:
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If I have 0.376 g of air, what are the moles of air, and what is the molar mass of air (g/mol)?
Please show how to get the answer.
Answer:
10.88g
Explanation:
The main components of dry air are N2 at 78.08% vol , O2 at 20.95% vol, and Argon at 0.934% vol. We will not be concerned with the lesser components because they will not have a significant effect on our answer. First we need to find the molar mass of dry air so we use the formula Mass = (percent mass * molar mass of gas) we then plug and chug: MM = (0.7804 * 28.01) + (0.2095 * 31.99)+(0.00934 * 39.95) which gives MM = 28.93 mol/gram
Now that we have the molar mass we use conversion factors to get 0.376g / 28.93mol = 10.88g
If the pH of a solution increases by 2 units (e.g., from 3 to 5), then the ratio of the new to the original hydronium ion concentration is
Answer:
This question is incomplete
Explanation:
This question is incomplete. However, generally hydronium ion (H₃O⁺) is produced when hydrogen ion (usually from an acid) is attracted to the negative pole of water (which is the oxygen part).
To determine the ratio in this case is simple, the ratio of the new to the original hydronium ion concentration is;
the calculate new concentration of hydronium ion, [H₃O⁺]
pH = -log[H₃O⁺] hence,
[H₃O⁺] = log⁻¹pH (meaning antilog of pH)
Kindly note that the pH to be used here is 2 + the original pH given
Hence, if the original pH given is 2
The new [H₃O⁺] will be 4
[H₃O⁺] = log⁻¹ 4
= 10000
Same formula should be used to determine the concentration of the original hydronium ion concentration using the original pH given.
Hence, [H₃O⁺] = log⁻¹ 2
= 100
The ratio of the new to the original hydronium ion concentration will be
10000:100
100:1
The ratio of the new to the original hydronium ion concentration when the pH of a solution increases by 2 is; 1: 100
The Hydroxonium ion is similar to the hydrogen ion concentration and is written as;. {H3O+¹}.
The formula for calculating the pH of a solution is;
pH = -log {H3O+¹}When the pH increases by 2 units; (e.g., from 3 to 5).
Therefore; By evaluation;
at pH = 3; {H3O+¹} = 10-³and at pH = 5; {H3O+¹} = 10-⁵.Therefore; 10-⁵/10-³ = 10-².
In essence; the ratio of the new to the original hydronium ion concentration is; 1 : 100
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8. Give the symbol of and the number of neutrons in one atom of:
(Round the MASS numbers so they are ALWAYS whole numbers…show your calculations)
Beryllium _____________ _________________
Calcium _______________ _______________
Sulfur _______________ ______________
Answer:
Explanation:
Given species;
Beryllium
Calcium
Sulfur
Unknown:
Give the symbol, number of neutrons and the mass number
Solution:
The symbols of the species are;
Beryllium - Be
Calcium - Ca
Sulfur - S
Number of neutrons:
Beryllium - 5
Calcium - 20
Sulfur - 16
Mass number :
Beryllium - 9
Calcium - 40
Sulfur - 32
Which of the following groups makes a neutral salt of the form AB
Answer:
Groups II and VI
Explanation:
Hello.
In this case, regarding cations from groups I whose oxidations states are +1, II whose oxidation states are +2 and III whose oxidation states are +3 we can see that when they combine with nonmetallic anions they exchange the charges via subscripts. In such a way, when bonding for instance calcium ions with sulfide ions, we obtain:
[tex]Ca^{2+}S^{2-}=Ca_2S_2[/tex]
Which can be simplified to give:
[tex]CaS[/tex]
If we do the same for oxygen, selenium and tellurium, we find the same form since nonmetals from group VIA could form anions with -2 as they need two electrons to attain the octet, therefore, answer is groups II and VI.
Regards.
Carla did an experiment by placing a piece of smooth clear glass in a piece of smooth Black Stone under a lamp for 20 minutes which prediction will most likely be supported by Carlas experiment results
A. the glass will feel warmer than the stone after 20 minutes
B. The stone will feel warmer than the glass after 20 minutes
C. The glass will reflect all of the light after 20 minutes
D. The stone will reflect all of the light after 20 minutes
Answer:
b
Explanation:
The stone will feel warmer than the glass after 20 minutes.
What is Conduction?This can be defined as a process of heat transfer which involves direct contact between the objects.
The stone and the lamp in contact with each other means heat will be transferred to the stone thereby making it warmer and the reason why option B was chosen as the most appropriate choice.
Read more about Conduction here https://brainly.com/question/893656
What is the basic unit of stucture and function of living things
For the 52nd electron must pair with one of the
electrons in the 5p orbital.
Answer:
This question is incomplete
Explanation:
This question is incomplete, however, the element that has 52 electrons only is Tellurium (Te) and when the electronic configuration of elements with more than 52 electrons are written, the 52nd electron is indicated/paired the same way the 52nd electron of Te is indicated/paired. Hence, while writing the electronic configuration of Te, it is written as
[Kr] 4d¹⁰ 5s² 5p⁴ where [Kr] is the electronic configuration of krypton. Based on this, we can deduce that the 52nd electron will be in the first orbital of the P subshell (as attached in the picture). This is because when indicating the electrons in the subshell, one electron will be spread across each orbital and if any electron is still remaining, it will be added starting from to the first orbital of the subshell, however no two electrons in an orbital in a subshell can have the same spin and hence must face opposite direction based on pauli's exclusion principle (as seen in attached); thus for the 5p-orbital of elements with 52 or more electrons, when one electron each is represented in each box (3 boxes in total) in the 5p-orbital, the remaining electron is paired with the the first electron in the first box of the 5p-orbital
Help Please!! (The Question is in the picture!)
Answer:
the answer that best describe the two methods is c
Explain how you could separate a mixture of ocean water (salt water) which has sand in it. You must separate all three substances.
Answer:
Salt and sand can be separated by mixing the two substances with water. The salt will dissolve into the water, while the sand will settle at the bottom of the mixture.
Explanation:
is water a mineral? HELP ASAP!!!!
Answer:
Water is not a mineral because it is not a solid.
Explanation: If water were turned into ice then it would be considered if water were turned into ice then it would be considered a mineral.
Ammonia molecule has got trigonal pyramidal geometry even though central atom gets sp3 hybridization. Give reason.
Which is the SI symbol for volume?
Answer:
In the International System of Units (SI), the standard unit of volume is the cubic metre (m3). The metric system also includes the litre (L) as a unit of volume, where one litre is the volume of a 10-centimetre cube.
Explanation:
i think
how to make the color pink?
answer:
tehehehe mix red and white!
Explanation:
Answer:
Red and white mixed together makes pink :)
Explanation:
Which of these is an example of a physical change?
Sugar dissolving in Warm water
Iron rusting in the presence of moist air
Wood burning in the presence of oxygen
Baking soda reacting with acid to form a gas
Answer:
hope it helps you❤❤❤
Explanation:
The physical change would be the sugar dissolving in water because no reaction is occurring.
sugar dissolving in warm water is an example of physical change.
physical change is doesn't alter the composition or the identity of the substance .
That's mean when you dissolves sugar in water, after a while the object will be the same which mean that the component doesn't change
Uneven heating of Earth's surface creates pressure differences that result in ____________.
Answer:
Updrafts (and can cause thunderstorms and other violent weather.)
Good luck, hope this helped!
What is another metal that has similar properties to gold?
Answer:
Copper and silver should work.
Explanation:
Determine the value of the equilibrium constant, Kgoal, for the reaction C(s)+12O2(g)+H2(g)⇌12CH3OH(g)+12CO(g), Kgoal=? by making use of the following information:
1. CO2(g)+3H2(g) ⇌ CH3OH(g)+H2O(g), K1 = 1.40×102
2. CO(g)+H2O(g) ⇌ CO2(g)+H2(g), K2 = 1.00×105
3. 2C(s)+O2(g) ⇌ 2CO(g), K3 = 2.10×1047
Answer:
1.71x10²⁷
Explanation:
If we sum 1/2 of (3) + 1/2 of (1):
1/2 (3.) C(s) + 1/2O₂(g) ⇌ CO(g), K₃ = √2.10×10⁴⁷ = 4.58x10²³
1/2 (1) 1/2CO₂(g) + 3/2H₂(g) ⇌ 1/2CH₃OH(g) + 1/2H₂O(g), K₁ = √1.40×10² = 11.8
C(s) + 1/2O₂(g) + 1/2CO₂(g) + 3/2H₂(g) ⇌ 1/2CH₃OH(g) + 1/2H₂O(g) + CO(g)
K' = 4.58x10²³ * 11.8 = 5.42x10²⁴
+1/2 (2):
1/2 CO(g) + 1/2H₂O(g) ⇌ 1/2CO₂(g) + 1/2H₂ (g), K = √1.00×10⁵ = 316.2
C(s) + 1/2O₂(g) + H₂(g) ⇌ 1/2 CHO₃H(g) + 1/2CO(g)
K'' = 5.42x10²⁴* 316.2 =
1.71x10²⁷How many moles are in 1.204 x 10^24 atoms of gold?
Answer:
The answer is 2 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question
N = 1.204 × 10²⁴ atoms of gold
We have
[tex]n = \frac{1.204 \times {10}^{24} }{6.02 \times {10}^{23} } \\ [/tex]
We have the final answer as
2 molesHope this helps you
I need help with my slide show, how is sandstone formed.
Answer:
Sandstone is a rock comprising mostly of minerals formed from sand. The stone gains its formation throughout centuries of deposits forming in lakes, rivers, or on the ocean floor. These elements group together with the minerals quartz or calcite and compresses. In time, the sandstone is formed by the pressure of these minerals coming together.
Explanation:
Answer:
Sandstone is a rock comprising mostly of minerals formed from sand. The stone gains its formation throughout centuries of deposits forming in lakes, rivers, or on the ocean floor. These elements group together with the minerals quartz or calcite and compresses.
Explanation:
PLS HELP ASAP... Assigning the atomic mass of 16.000 to oxygen, what is the atomic mass of sulfur?
A solid that forms from liquids in a chemical reaction is called a
PLZ HELP
Answer:
precipitate
Explanation:
Assign an oxidation number to each atom in the reactants.
4Al(s)+3O2(g)→2Al2O3(s)
(Oxidation number for both Al and O is needed)
Answer:
Al⁺³ , O⁻²
Explanation:
This is an oxidation reduction reaction (Redox).
Chemical reaction:
4Al + 3O₂ → 2Al₂O₃
The oxidation state on Al and O on left hand side is zero. On right hand side Al is present in +3 oxidation state while O is present in -2 oxidation sate.
Oxygen is reduced and Al is oxidized in this reaction.
The oxidation reduction reactions are called redox reaction. These reactions are take place by gaining or losing the electrons and oxidation state of elements are changed.
Oxidation:
Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
what is the change in enthalpy in kilojoules when 3.24 g of CH3OH is completely reacted according to the following reaction 2 CH3OH -->4 CH4 + O2 ∆H
=252.8 Kj
Answer:
12.78 kJ
Explanation:
The correct balanced reaction would be
[tex]2CH_3OH\rightarrow 2CH_4+O_2\Delta H=252.8\ \text{kJ}[/tex]
Mass of methanol = [tex]3.24\ \text{g}[/tex]
Moles of methanol can be obtained by dividing the mass of methanol with its molar mass [tex](32.04\ \text{g/mol})[/tex]
[tex]\dfrac{3.24}{32.04}=0.10112\ \text{moles}[/tex]
Enthalpy change for the number of moles is given by
[tex]\dfrac{\text{Number of moles of methanol in the reaction}}{\text{Enthalpy change in the reaction}}=\dfrac{\text{Number of moles in 3.24 g of methanol}}{\text{Enthaply in change in the mass of methanol}}[/tex]
[tex]\\\Rightarrow\dfrac{2}{252.8}=\dfrac{0.10112}{\Delta H}\\\Rightarrow \Delta H=\dfrac{0.10112\times 252.8}{2}\\\Rightarrow \Delta H=12.781568\approx 12.78\ \text{kJ}[/tex]
The change in enthalpy is 12.78 kJ.
When 3.24 g of CH₃OH are decomposed, the change in the enthalpy is 12.8 kJ.
Let's consider the following thermochemical equation.
2 CH₃OH ⇒ 4 CH₄ + O₂ ∆H = 252.8 kJ
First, we will convert 3.24 g of CH₃OH to moles using its molar mass (32.04 g/mol).
[tex]3.24 g \times \frac{1mol}{32.04g} = 0.101 mol[/tex]
According to the thermochemical equation, 252.8 kJ are absorbed when 2 moles of CH₃OH react. The enthalpy change when 0.101 moles of CH₃OH react is:
[tex]0.101 mol \times \frac{252.8 kJ}{2mol} = 12.8 kJ[/tex]
When 3.24 g of CH₃OH are decomposed, the change in the enthalpy is 12.8 kJ.
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WHAT IS THE DENSITY OF A BLOCK WITH A
VOLUME OF 24 ML AND A MAS 3.2 G?
Answer:
The answer is 7.5 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
So we have
[tex]density = \frac{24}{3.2} \\ [/tex]
We have the final answer as
7.5 g/mLHope this helps you
What pH might you expect from a weak acid and a strong base if equal concentrations ?
13.5
7.0
3.2
10.4
Answer:
7.0
Explanation:
In the titration of a weak acid and a strong base, the pH or equivalence point will be greater than 7. Therefore, option D is correct.
What is pH?The pH of the solution can be described as the negative logarithm of hydrogen ions (H⁺) concentration. Mathematically, the pH value is generally inversely proportional to the hydrogen ion's concentration.
pH = -log ([H⁺])
In chemistry, the pH scale is used to determine the basicity or acidity of an aqueous solution. Acidic solutions can be calculated to have lower pH values than alkaline solutions.
The pH scale has a scale of 0 to 14 while pH 7.0 is neutral. A low pH of about 1 or 2 is acidic and a high pH of 12 or 14 is basic.
The pH value of the weak acid and a strong base solution will be greater than seven because the conjugate base of a weak acid is weakly basic. Therefore, the expected pH from a weak acid and a strong base if equal concentrations will be greater than 7 can be 10.4.
Learn more about pH value, here:
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C10H22 + O2 -- CO2 + H2O balance
Answer:
1,31÷2 =10,11
Explanation:
c10h22+31÷2o2=10co2+11h2o