Answer:
A. ΔH∘rxn = 21.9 KJ/mol
B. ΔH∘rxn = 103 KJ/mol
C. C2H5OH + 3O2 → 2CO2 + 3H2O
Explanation:
A.
The standard reaction equation is given as:
aA + bB → cC + dD
Its standard enthalpy is given as:
ΔH∘rxn = cΔH∘f(C) + dΔH∘f(D) − aΔH∘f(A) − bΔH∘f(B)
Reaction given to us is:
H2O(l) + CCl4(l) → COCl2(g) + 2HCl(g)
So, its standard enthalpy will be:
ΔH∘rxn = (1)ΔH∘f(CoCl2 (g)) + (2)ΔH∘f(HCl(g)) − (1)ΔH∘f(H2O(l)) − (1)ΔH∘f(CCl4(l))
using the values from table:
ΔH∘rxn = - 218.8 KJ/mol + (2)(- 92.3 KJ/mol) - (- 285.8 KJ/mol) - (- 139.5 KJ/mol)
ΔH∘rxn = 21.9 KJ/mol
B.
Reaction given to us is:
2A + B ⇌ 2C + 2D
So, its standard enthalpy will be:
ΔH∘rxn = (2)ΔH∘f(C) + (2)ΔH∘f(D) − (2)ΔH∘f(A) − (1)ΔH∘f(B)
using the values from table:
ΔH∘rxn = (2)181 KJ/mol + (2)(- 523 KJ/mol) - (2)(- 225 KJ/mol) - (- 337 KJ/mol)
ΔH∘rxn = 103 KJ/mol
C.
Balanced equation for combustion of ethanol is:
C2H5OH + 3O2 → 2CO2 + 3H2O
Answer: is A B abd C
The protein lysozyme unfolds at a transition temperature of 75.5°C, and the standard enthalpy of transition is 509 kJ mol-1. Calculate the entropy of unfolding of lysozyme at 25.0°C, given that the difference in the constant-pressure heat capacities upon unfolding is 6.28 kJ K-1 mol-1 and can be assumed to be independent of temperature. Hint: Imagine that the transition at 25.0°C occurs in three steps: (i) heating of the folded protein from 25.0°C to the transition temperature, (ii) unfolding at the transition temperature, and (iii) cooling of the unfolded protein to 25.0°C. Because the entropy is a state function, the entropy change at 25.0°C is equal to the sum of the entropy changes of the steps.
Answer:
0.4774 KJ/K.mol
Explanation:
We are told that the transition at 25.0°C occurs in three steps. Steps i, ii and iii.
Thus;
the entropy of unfolding of lysozyme = ΔS_i + ΔS_ii + ΔS_iii
Now,
C_p,m(unfolded protein) = C_p,m(folded protein) + 6.28 kJ/K.mol
Now, for the first process, ΔS_i is given as;
ΔS_i = C_p,m × In(T2/T1)
We are given;
T1 = 25°C = 25 + 273.15K = 298.15 K
T2 = 75.5°C = 75.5 + 273.15 K=348.65 K
Thus;
ΔS_i = C_p,m × In(348.65/298.15)
Now, for the third process, ΔS_iii is given as;
ΔS_iii = (C_p,m + 6.28 kJ/K.mol) × In(T1/T2)
Thus;
ΔS_iii = (C_p,m + 6.28 kJ/K.mol) × In(298.15/348.65)
Now, we don't know C_pm. So, we have to find a way to eliminate it. We will do it by rewriting In(298.15/348.65) in such a way that when ΔS_iii is added to ΔS_i, C_p,m will cancel out. Thus;
In(298.15/348.65) can also be written as;
In(348.65/298.15)^(-1) or
- In(348.65/298.15)
Thus;
ΔS_iii = - [(C_p,m + 6.28 kJ/K.mol) × In(298.15/348.65)]
Now, let's add ΔS_iii to ΔS_i to get;
ΔS_i + ΔS_iii = [C_p,m × In(348.65/298.15)] + [(-C_p,m - 6.28 kJ/K.mol) × In(348.65/298.15)]
ΔS_i + ΔS_iii = [C_p,m × In(348.65/298.15)] - [C_p,m × In(348.65/298.15)] - [6.28In(348.65/298.15)]
First 2 terms will cancel out to give;
ΔS_i + ΔS_iii = -6.28In(348.65/298.15)
ΔS_i + ΔS_iii = -0.9826 KJ/K.mol
Now,for process ii;
ΔS_ii = standard enthalpy of transition/Transition Temperature
Thus;
ΔS_ii = (509 KJ/K.mol)/348.65
ΔS_ii = 1.46 KJ/K.mol
Thus;
the entropy of unfolding of lysozyme = ΔS_i + ΔS_ii + ΔS_iii = -0.9826 + 1.46 = 0.4774 KJ/K.mol
The first reaction in the Ostwald process for the production of nitric acid involves the combustion of ammonia
4NH3(g)+5O2(g)=4NO(g)+6H2O(g)
a) Estimate ΔH^o (in kJ) for this reaction using average bond energies.
b) Calculate ΔH^o (in kJ) for this reaction using standard heats of formation.
c) Briefly explain why the value for ΔH^o, calculated using average bond energies, is only considered to be an estimate of the standard enthalpy change for the reaction
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.
What energy transformation is found in an electric motor?
Answer:
electrical energy is converted into mechanical energy.
Explanation:
An electric motor contains a permanent magnet and an electromagnet. As the poles of the electromagnet and the permanent magnet constantly repel each other, the electric motor makes a rotational motion. The increase in current or the increase in power of the magnet causes the electric motor to rotate faster.
Knowing that the distances the truck traveled during each segment were 30, 45, 50, and 65 respectively, what was the total distance traveled by the truck?
Answer:
The distance the truck traveled is 190
Explanation:
I added 30, 45, 50, 65 together to get the total distance
Which scientific term names rocks formed from magma?
A. Intrusive
B. Lava
C. Gabbro
D. Extrusive
Answer:
A Intrusive
Explanation:
I go to K12 and they say that's the answer
Example of balanced force
It would be A since a balanced force would stay the same.
What mass of cobalt contains the same number of atoms as 57.0 g fluorine
Answer:
This is a chemistry problem i'm having some issues with. I have a test tomorrow and need all the help I can get.
What I thought to do was first figure out the atoms of 57.0g F, which I got 2x10^24.
Then I tried to convert it into grams Co.
Would I just divide it by 6.022x10^23 and then multiply by the molar mass of Co?
Is the answer 195.7g?
Thanks!
Explanation:
The mass of Cobalt that contains the same number of atoms in 57 g of fluorine is 177 g
We'll begin by calculating the number atoms in 57 g of fluorine. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of F = 6.02×10²³ atoms
But,
1 mole of F = 19 g
Thus,
19 g of F = 6.02×10²³ atoms
Therefore,
57 g of F = [tex]\frac{57 * 6.02*10^{23} }{19}\\\\[/tex]
57 g of F = 1.806×10²⁴ atoms
Finally, we shall determine the mass of Cobalt that contains 1.806×10²⁴ atoms. This can be obtained:
From Avogadro's hypothesis,
6.02*10²³ atoms = 59 g of Co
Therefore,
1.806×10²⁴ atoms = [tex]\frac{59 * 1.806 *10^{24} }{6.02*10^{23} }\\\\[/tex]
1.806×10²⁴ atoms = 177 g of Co
Thus, we can conclude that 177 g of Cobalt (Co) contains the same number of atoms in 57 g of fluorine
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. -9 + 6 - (-2)
Answers?
Answer:
-9+6-(-2)
-9+6+2
-9+8
-1 is the answer
Explanation:
A solid ball has a mass of 50 grams and a volume
of 20 cm? What is the ball's density?
Answer:
Density = 50 / 20 = 2.5 gram/ cm^3
Explanation:
Answer is 2.5 grams/ cm^3
Halley’s Comet is a comet that passes close to earth every 75 years. Based on the passage , which gravitational attraction has the most influence on the movement of this astronomical object?
Answer:
Attraction between the comet and the Sun
Explanation:
1. What is the mass of the cart with a constant net force of 200N is exerted
to accelerate from rest to a velocity of 40m/s in 10 s.
A. 0.5 kg
C. 50 kg
B. 5 kg
D. 500 kg
Answer:
50
Explanation:
so you'll have to apply Newton's 2nd law which is F=ma and then substitute the values that you already have in the question as in, the force is 200 and you'll have to find the acceleration by working it out which is 4m/s² and then find the mass by dividing 200 by 4 so the actual mass is 50kg ✌️❤️
Taking into account the Newton's second law, the mass of the cart is 50 kg.
You have to know that Newton's second law states that this force will change the speed of an object because the speed and / or direction will change. These changes in velocity are called acceleration.
So, Newton's second law defines the relationship between force and acceleration mathematically. This law says that the acceleration of an object is directly proportional to the sum of all the forces acting on it and inversely proportional to the mass of the object.
Mathematically, Newton's second law is expressed as:
F= m×a
where:
F = Force [N] m = Mass [kg] a = Acceleration [m/s²]Acceleration relates the changes in velocity with the time in which they occur. So:
[tex]a=\frac{final velocity - initial velocity}{time}[/tex]
In this case:
F= 200 Nm= ?[tex]a=\frac{40 \frac{m}{s}-0\frac{m}{s} }{10 s} = 4 \frac{m}{s^{2} }[/tex]Replacing in the expression for Newton's Second Law:
200 N= m× 4 m/s²
Solving:
m= 200 N÷4 m/s²
m= 50 kg
Finally, the mass of the cart is 50 kg.
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brainly.com/question/23845187?referrer=searchResults brainly.com/question/13959891?referrer=searchResultsWhy can certain things only be turned into certain other things? For example, if you mixed flour, sugar, eggs, and other ingredients, you will not make gold. You will not make rubber, or diamond, or straw either. Why not? In the following space, explain why someone cannot make gold by mixing flour, sugar, and eggs.
Answer:
You cannot make gold with bakery ingredients as gold is made with hydrogen and helium. Not everything follows the same recipe as some objects. There are different recipes for each material which makes sense because minerals aren't made of wheat. Those minerals feel like stone and act like stone, so it wouldn't be logical if it was crafted with flour, sugar and eggs.
Hope this helps.
Gold is a metal of higher value. It cannot be made by simply mixing any substance. Because every substance is made of its own atoms or molecules and it cannot be recreated by other atoms.
What is gold?Gold is 79th element in periodic table. It is a transition metal placed in d-block elements. Gold is a precious metal have been used in ornaments and other coatings.
Metals are hard, and they have some peculiar properties such as ductility, malleability. metallic luster etc. Gold is hard, shiny malleable and ductile and thus it can be easily modified into desired shapes and size.
Every substance is made of its own atoms and molecules. Gold is made of its atoms similarly, silver is made of its own atoms. In such a way everything is made by their characteristics atoms which cannot be recreated from other substances. It can only be produced from its minerals and ores.
Hence, gold cannot be produced from materials like rubber, strew ether etc.
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How many grams are in 0.005 moles of lead (IV) sulfate, Pb(SO4)2 Group of answer choices 1.5 g 502.74 g 0.0045 g 1.996 g
Answer:
[tex]m_{Pb(SO_4)_2}=1.996 g[/tex]
Explanation:
Hello.
In this case, given the formula of the lead (IV) sulfate, we can compute its molar mass as shown below:
[tex]M_{Pb(SO_4)_2}=m_{Pb}+2*m_S+2*4*m_O\\\\M_{Pb(SO_4)_2}=207.2+2*32+2*4*16\\\\M_{Pb(SO_4)_2}=399.2g/mol[/tex]
Thus, by applying the following mole-mass relationship, we obtain the mass of 0.005 moles of lead (IV) sulfate:
[tex]m_{Pb(SO_4)_2}=0.005mol*\frac{399.2g}{1mol} \\\\m_{Pb(SO_4)_2}=1.996 g[/tex]
Best regards.
A golden nugget displaces 89.60 mL of water when submerged. If the density of gold is 19.32 g/cm² what is the mass of the nugget
Answer:
The answer is 1731.1 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
density = 19.32 g/cm³
1 mL = 1 cm³
89.60 mL = 89.60 cm³
volume = 89.60 cm³
So we have
mass = 19.32 × 89.60 = 1731.072
We have the final answer as
1731.1 gHope this helps you
which objects would have a greater gravitational force between them, Objects A and B, or Objects B and C? PLEASE HELPPP
Answer:
hmm:
Explanation:
Unless I am crazy, there should be an image attached to this. But, you can use this formula:
[tex]F = G\frac{m_1m_2}{r^2}[/tex] where F is the force, G is a constant, m1 and m2 are the masses of the objects, and r is the distance between the objects.
At room temperature, the element bromine is a liquid with a density of 3.12 g/mL.
a Calculate the mass of 542 mL of bromine.
Mass = blank g
b What volume does 60.0 g of bromine occupy?
Volume =
mL
Answer:
A. 1691.04 g
B. 19.23 mL
Explanation:
The following data were obtained from the question:
Density of bromine = 3.12 g/mL.
A. Determination of the mass of bromine.
Density of bromine = 3.12 g/mL.
Volume of bromine = 542 mL
Mass of bromine =?
Density = mass /volume
3.12 = mass /542
Cross multiply
Mass of bromine = 3.12 × 542
Mass of bromine = 1691.04 g
B. Determination of of volume of bromine.
Density of bromine = 3.12 g/mL.
Mass of bromine = 60 g
Volume of bromine =...?
Density = mass /volume
3.12 = 60 / volume
Cross multiply
3.12 × volume = 60
Divide both side by 3.12
Volume of bromine = 60/3.12
Volume of bromine = 19.23 mL.
The answer to both solution is as follows:-
1691.04 g 19.23 mL
All the data is given in the question,
Density of bromine = 3.12 g/mL. Volume of bromine = 542 mL
The formula we will use is as follows:- [tex]Density = \frac{mass}{volume}[/tex]
[tex]Mass of bromine = 3.12 * 542[/tex] = 1691.04 g
Hence, the mass of the bromine is 1691.04g
The volume of bromine = [tex]\frac{60}{3.12}[/tex]
The volume of bromine is 19.23mL.
Hence, the mass and the volume are 1691.4g and 19.23ml.
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what percent of earths carbon is stored in soil?
Answer:80%
Explanation:Total C in terrestrial ecosystems is approximately 3170 gigatons (GT; 1 GT = 1 petagram = 1 billion metric tons). Of this amount, nearly 80% (2500 GT) is found in soil (Lal 2008).
The liter is defined as
a
1000 c3.
b
1000 m3.
c
1000 cm3.
d
1000 g3.
Answer:
C
Explanation: I mL = 1 cm3 and 1 L = 1000 mL so 1 L - 1000 cm3
Answer:
d
Explanation:
Extra points!
Classify each of the following as a physical change or a chemical change.
grinding glass:
rusting of iron:
burning a candle:
sanding wood:
Grinding of glass sanding of wood are physical changes. Rusting of iron and burning candle are chemical changes.
What are chemical changes ?Chemical changes involves the formation or breaking of chemical bonds that leads to a new product. Whereas, physical changes does not involves any change in chemical bonds. Phase change, change in size, shape etc. are physical changes.
Grinding glass will does not make any change in chemical bonds of glass materials . Just their size gets reduces and forms their dust particles. Thus, it is a physical change. Sanding the wood also a physical change.
Rusting of iron is the formation of red iron oxide by the reaction of iron with oxygen from air or water. This oxide will spread over the surface of the metal and eventually gets corroded. This is a chemical change where a new product is formed.
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Rational numbers are?
✅The racial numbers are all the numbers that can represent as the quotient of two numbers enter or, more precisely, an entity and a natural positive; The term "racial" refers to a fraction or part of a whole.
IamSugarBee
John eats a 1 lb steak, 8 chicken wings, a half pound of fries, potato salad, coleslaw,
and 6 slices of pizza at Food Emporium, his favorite restaurant. The waiter comes by
to offer John a slice of cake but he refuses because cake doesn't sound appetizing to
him although at any other time, John would have most likely ordered a slice of cake.
This is an example of which of the following phenomena.
O allesthesia
O Pteradactyl-like eating behaviors
O somatosensory simulation
O anorexia
The given example is a good description of the phenomena is:
D. AnorexiaAnorexia is an eating disorder which makes a person to feel that any extra food is going to cause him to become obese and because of this, he would reduce his intake of food.
As a result of this, they tend to get some health issues as a result of their refusal to eat certain foods or even eat at all. This is evident in the given example of John refusing to eat an extra slice of cake after having a huge meal at his favorite restaurant.
Therefore, the correct answer is option D
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Which is the function of space observatory technology?
classify objects in space
collect soil and rock samples
carry astronauts and equipment
capture panoramic surface images
Answer:
A
Explanation:
Classify objects in space
Answer:
its A
Explanation:
just did it
Name:
1. Draw the Lewis Dot diagram for the molecule AB2C. Element A has 4 valence electrons
and requires a full octet. Element B has 1 valence electron, but only gets 2 valence
electrons to have a full outer shell. Element C has 6 valence electrons and needs
to
have 8 valence electrons for a full octet.
Identify the chane name for the molecule
Answer:
See attached picture and explanation.
Explanation:
Hello!
In this case, given the instruction on the molecule, we can infer that A is the central atom as it must have a full octet which is reached via one bond with each B atom. Moreover, via a double bond with C, both A and C are able to have the required full octet as shown on the attached picture.
For the name, it looks like the formaldehyde ([tex]CH_2O[/tex]) which has two single-bonded hydrogen atoms and one double-bonded oxygen atom in order to have a full octet forth both carbon and oxygen.
Regards.
What would happen if they had no sunlight???
Answer plants will die and with out plants we will die
Explanation:
If it requires 67 J of heat to raise the temperature of a piece of iron by 5.0°C, calculate the mass of the iron. The specific heat of iron is 0.46 J/g·°C.
Explanation:
E= m.c. delta T
67 = m . 0.46. 5
m = 67/(0.46*5)
m = 67/2.3
m= 29.13 g
gaseous butane (CH3(CH2)2CH3) will react with gaseous oxygen (O2) to produce carbon dioxide (CO2) and gaseous water (H2O). suppose 1.16 g of butane is mixed with 7.6 g of oxygen. calculate the minimum mass of butane that could be left over by the chemical reaction. round your answer to 2 significant digits.
We are given the equation:
2C4H10(g)+13O2(g)→8CO2(g)+10H2O(g)
we are also given that 1.16 grams of butane and 7.6 grams of oxygen are used in this reaction
Moles of Butane provided in the reaction:
Molar mass of butane = 58 g/mol
Number of moles = given mass / molar mass
Number of moles = 1.16 / 58
Number of moles = 0.02 moles
Moles of Oxygen provided in the reaction:
Molar mass of oxygen = 16 g/mol
Number of moles = given mass / molar mass
Number of moles = 7.6 / 16
Number of moles = 0.475 moles
Finding the Limiting reagent:
Since the number of moles of Butane is less that of oxygen, butane is the limiting reagent
So, number of moles of Oxygen used = Number of moles of Butane * 13/2
Number of moles of O2 used = 0.02 * 13/2 = 26 / 200 = 0.13 moles
Since Butane is the limiting reagent, the mass of butane left over is 0 grams
rounding to 2 significant digits: 00 grams of Butane
Definition of reactant
Noun
a substance that takes part in and undergoes change during a reaction.
What are the materials Identify a cube
Answer:
If the prime factors of a number are grouped in triples of equal factors, then that number is called a perfect cube. In order to check whether a number is a perfect cube or not, we find its prime factors and group together triplets of the prime factors. If no factor is left out then the number is a perfect cube.
Explanation:
A rectangular swimming pool has the dimensions of 26m long, 4m wide, and 2.5 m deep (high). The density of the water in the pool is 1.62 g/m3. What is the mass of the water in the pool? (hint: volume of a rectangle is L x w x h) Show your work!
Answer:
[tex]m=421.2g[/tex]
Explanation:
Hello.
In this case, we first compute the volume of the pool via:
[tex]V=L*W*H\\\\V=26m*4m*2.5m\\\\V=260m^3[/tex]
Then, since the density is defined as the mass divided by the volume, we compute the mass as follows:
[tex]\rho=\frac{m}{V}\\ \\m=\rho*V\\\\m=1.62g/m^3*260m^3\\\\m=421.2g[/tex]
Best regards.
What is the resistance of a circuit with 120 volts and 30 amps.
Answer:
40
Explanation:
120/30=40