The enthalpy of formation for CO2 (s) and CO2 (g) is: -427.4 KJ/mole and -393.5 KJ/mole, respectively. The sublimation of dry ice is described by CO2 (s) → CO2 (g).

The enthalpy needed to sublime 986 grams of CO2 is:
(a) 181.5 Kcal
(b) 611.7 Kcal
(c) 248.3 Kcal
(d) 146.2 Kcal

Answers

Answer 1

Answer:

a. 181.5 kcal

Explanation:

Step 1: Calculate the enthalpy of the process (ΔH°).

Let's consider the following process.

CO₂(s) → CO₂(g)

We can calculate the enthalpy of the process using the following expression.

ΔH° = ∑ np × ΔH°f(p) - ∑ nr × ΔH°f(r)

ΔH° = 1 mol × ΔH°f(CO₂(g)) - 1 mol × ΔH°f(CO₂(s))

ΔH° = 1 mol × (-393.5 kJ/mol) - 1 mol × (-427.4 kJ/mol) = 33.9 kJ

According to the balanced equation, 33.9 kJ are required to sublime 1 mole of CO₂.

Step 2: Convert 986 g of CO₂ to moles

The molar mass of CO₂ is 44.01 g/mol.

986 g × 1 mol/44.01 g = 22.4 mol

Step 3: Calculate the enthalpy needed to sublime 22.4 moles of CO₂

22.4 mol × 33.9 kJ/1 mol = 759 kJ

We can convert it to Kcal using the conversion factor 1 kcal = 4.184 kJ.

759 kJ × 1 kcal/4.184 kJ = 181.5 kcal


Related Questions

tính ΔH° của phả ứng sau ở 200°C
CO+1÷2O=CO2
ΔH°

Answers

Could u explain more.?

How many milliliters of 0.204 Mol KMnO4 are needed to react with 3.24 g of iron(II) sulfate, FeSO4? The reation is as folows. 10FeSO4(aq) + 2 KMnO4(aq) = 5Fe2(SO4)3(aq) + 2MnSO4(aq) + K2SO4(aq) + 8H2O(l)​

Answers

Answer:

Explanation:

nFeSo4=3.36/152

nkmno4=1/5nFeSO4

V=17.68 ml

An equilibrium mixture of PCl5(g), PCl3(g), and Cl2(g) has partial pressures of 217.0 Torr, 13.2 Torr, and 13.2 Torr, respectively. A quantity of Cl2(g) is injected into the mixture, and the total pressure jumps to 263.0 Torr at the moment of mixing. The system then re-equilibrates. The chemical equation for this reaction is

Answers

Answer:

p'PCl3 =  6.8 torr

p'Cl2 =26.4 torr

p'PCl5 =223.4 torr

Explanation:

An equilibrium mixture of PCl5(g), PCl3(g), and Cl2(g) has partial pressures of 217.0 Torr, 13.2 Torr, and 13.2 Torr, respectively. A quantity of Cl2(g) is injected into the mixture, and the total pressure jumps to 263.0 Torr at the moment of mixing. The system then re-equilibrates. The chemical equation for this reaction is

PCl3(g) + Cl2(g) ---> PCl5(g)

Calculate the new partial pressures after equilibrium is reestablished. [in torr]

pPCl3

pCl2

pPCl5

Step 1: Data given

Partial pressure before adding chlorine gas:

Partial pressure of PCl5 = 217.0 torr

Partial pressureof PCl3 = 13.2 torr

Partial pressureof Cl2 = 13.2 torr

A quantity of Cl2(g) is injected into the mixture, and the total pressure jumps to 263.0 Torr at the moment of mixing

Step 2: The equation

PCl3(g)+Cl2(g) ⇔ PCl5(g)

Step 3: The expression of an equilibrium constant before adding chlorine gas

Kp = pPCl5 / (pPCl3 * pCl2)

Kp = 217.0 / (13.2 * 13.2)

Kp =  1.245

Step 4:  The expression of an equilibrium constant after adding chlorine gas

Partial pressure of PCl5 = 217.0 torr

Partial pressure of PCl3 = 13.2

Partial pressure of Cl2 = TO BE DETERMINED

Step 5: The total pressure of the system

Ptotal = pPCl5 + pPCl3 + pCl2

263.0 torr = 217.0 torr + 13.2 torr + pCl2

pCl2 = 263.0 - 217.0 -13.2 = 32.8 torr

Step 6: The initial pressure

The equation: PCl3(g)+Cl2(g) ⇔ PCl5(g)

pPCl3 = 13.2 torr

pCl2 = 32.8 torr

pPCl5 = 217.0 torr

Step 7: The pressure at the equilibrium

p'PCl3 = (13.2 -x) torr

p'Cl2 = (32.8 - x) torr

p'PCl5 = (217.0 + x) torr

Step 8: The equilibrium constant

'Kp =  p'PCl5 / (p'PCl3 * p'Cl2)

1.245 = (217.0+x) / ((13.2-x)(32.8-x)

x = 6.40 torr

p'PCl3 = 13.2 -6.40 = 6.8 torr

p'Cl2 = 32.8 - 6.40 =26.4 torr

p'PCl5 = 217.0 + x) 6.4 = 223.4 torr

Hydrogen is manufactured on an industrial scale by this sequence of reactions:

CH4(g) + H2O(g) ⇆ CO(g) + 3H2(g)
CO(g)+ H2O(g) ⇆ CO(g) + H2(g)

The net reaction is:
CH4(g) + H2O(g) ⇆ CO(g) + 4H2(g)

Write an equation that gives the overall equilibrium constant K in terms of the equilibrium constants K1 and K2.

Answers

Answer:

[tex]K=K_1*K_2\\\\K=\frac{[H_2]^3[CO_2][H_2]}{[CH_4][H_2O][H_2O]}[/tex]

Explanation:

Hello there!

In this case, for the given chemical reaction, it turns out firstly necessary to write the equilibrium expression for both reactions 1 and 2:

[tex]K_1=\frac{[CO][H_2]^3}{[CH_4][H_2O]} \\\\K_2=\frac{[CO_2][H_2]}{[CO][H_2O]}[/tex]

Now, when we combine them to get the overall expression, we infer these two are multiplied to get:

[tex]K=K_1*K_2\\\\K=\frac{[CO][H_2]^3}{[CH_4][H_2O]} *\frac{[CO_2][H_2]}{[CO][H_2O]}\\\\K=\frac{[H_2]^3[CO_2][H_2]}{[CH_4][H_2O][H_2O]}[/tex]

Regards!

HELP! How is the mass number of an atom calculated?
A - total number of electrons

B - total number of protons

C - protons plus neutrons

D - electrons plus neutrons

Answers

The answer is C. Mass number = protons + neutrons

Carboxylic acid derivatives undergo hydrolysis to make carboxylic acids.

a. True
b. False

Answers

Answer:

TRUE

Explanation:

All carboxylic acid derivatives have in common the fact that they undergo hydrolysis (a cleav- age reaction with water) to yield carboxylic acids. with hydroxide ion to yield a carboxylate salt and an alcohol. The carboxylic acid itself is formed when a strong acid is subsequently added to the reaction mixture.

PLS MARK BRAINLIEST

True

All carboxylic acid derivatives have in common the fact that they undergo hydrolysis (a cleav- age reaction with water) to yield carboxylic acids. with hydroxide ion to yield a carboxylate salt and an alcohol. The carboxylic acid itself is formed when a strong acid is subsequently added to the reaction mixture.
PLS MARK BRAINLY PLSSSSSSS

The first step of electrophilic aromatic substitution involves the formation of the arenium ion intermediate.

a. True
b. Fasle

Answers

Answer:

True

Explanation:

Aromatic compounds undergo substitution rather than addition reactions because the aromatic structure is maintained.

Electrophilic aromatic substitution begins with attack of the electrophile on the aromatic ring to yield a delocalized intermediate called the arenium intermediate. Loss of hydrogen from this intermediate yields the final product.

An ionic bond is a bond

Answers

Answer:

That involve the complete transfer of an electron from one atom of an element to another

The density of a gas cannot be measured.
True
False

Answers

Answer:

False

Explanation:

Answer:

False

Explanation:

A cyclopropane-oxygen mixture is used as an anesthetic. If the partial pressure of cyclopropane in the mixture is 330 mmHg and the partial pressure of the oxygen is 1.0 atm, what is the total pressure of the mixture in torr

Answers

Answer:

1090 Torr

Explanation:

Step 1: Given data

Partial pressure of cyclopropane (pC₃H₆): 330 mmHg (330 Torr)Partial pressure of oxygen (pO₂): 1.0 atm

Step 2: Convert pO₂ to Torr

we will use the conversion factor 1 atm = 760 Torr.

1.0 atm × 760 Torr/1 atm = 760 Torr

Step 3: Calculate the total pressure of the mixture (P)

The total pressure of the mixture is the sum of the partial pressures of the gases.

P = 330 Torr + 760 Torr = 1090 Torr

Draw a relative energy diagram showing a conformational analysis of 2,2-dichloropropane along C1-C2 bond. Clearly label all staggered conformations and all eclipsed conformations with the corresponding Newman projections.

Answers

Answer:

^#))(899900000)My020

Identify the compound with ionic bonds.
CO
H2O
Ne
KCl
O2

Answers

Answer:

CO =Coordinate Covalent Bond ,H2O = Water , NE= Nickel or Neon ,KCL=Potassium Chloride and O2 = Water

Explanation:

hope you wiill get help from me please follow me

Write chemical equations and corresponding equilibrium expressions for each of the two ionization steps of carbonic acid. Part A Write chemical equations for first ionization step of carbonic acid. Express your answer as a chemical equation. Identify all of the phases in your answer.

Answers

Solution :

[tex]H_2CO_3[/tex] is considered a diprotic acid.

Sp it can dissociate in solution by giving two protons.

Chemical equations for the first step of carbonic acid is :

First ionization

[tex]$H_2CO_3(aq) + H_0(1) \rightleftharpoons H_.O^+(aq) + HCO_3^-(aq)$[/tex]

Equilibrium constant expression is

[tex]$K_{a}_{1}=\frac{[H_3O^+][HCO_3^-]}{[H_2CO_3]}$[/tex]

Second ionization -

[tex]$HCO_3^-(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + CO_3^{2-}(aq)$[/tex]

Equilibrium constant expression is

[tex]$K_{a2}=\frac{[H_3O^+][CO_3^{2-}]}{[HCO_3^-]}$[/tex]

Select all of the following statements that represent the differences between a voltaic cell and an electrolytic cell. Group of answer choices The electrodes will change in mass for only the electrolytic cell Reduction happens at the cathode for only the electrolytic cell The redox reaction is spontaneous for only voltaic cell Electrode with the lowest reduction potential is reduced in an electrolytic cell A potential is generated when the voltaic cell runs

Answers

Answer:

The electrodes will change in mass for only the electrolytic cellElectrode with the lowest reduction potential is reduced in an electrolytic cellA potential is generated when the voltaic cell runs

The following statements represent the differences between a voltaic cell and an electrolytic cell -

The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runsThe process occurs spontaneously in the voltaic cells due to chemical reactions.electrolytic cell electrical energy is needed for the chemical reactions to occur.

A potential is generated by a chemical reaction and for electrolytic cells, a potential is needed.

there is definitely an exchange of mass in a voltaic cellthe species with lower reduction potential always gets reduced and in any electrochemical cell reduction occurs at the cathode.

The following statements represent the differences between a voltaic cell and an electrolytic cell -

The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runs

Thus, The following statements represent the differences between a voltaic cell and an electrolytic cell -

The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runs

Learn more:

https://brainly.com/question/3614785

The Bohr effect:_____.
a. explains through the Bohr model of the atom why Fe2+ will bind O2 in heme but Fe3+ will not.
b. contributes to binding of O2 by hemoglobin in lungs and release of O2 from hemoglobin in tissues.
c. applies to both myoglobin and hemoglobin.
d. relates [H+] to [CO2].

Answers

Answer:

b. contributes to binding of O2 by hemoglobin in lungs and release of O2 from hemoglobin in tissues.

Explanation:

The Bohr effect is a phenomenon described by Christian Bohr. Is an affinity that binds oxygen and hemoglobin and is inversely related to the concentration of carbon dioxide. As CO2 reacts with water and an increase in CO2 results in a decrease in blood ph.

Compounds such as butane and isobutane that have the same molecular formula but differ in the order in which the atoms are connected are called ____________

a. trans isomers

b. cis isomers

c. conventional isomers

d. constitutional isomers​

Answers

Answer:

One compound, called n-butane, where the prefix n- represents normal, has its four carbon atoms bonded in a continuous chain. The other, called isobutane, has a branched chain. Different compounds that have the same molecular formula are called isomers.

Answer:

d. constitutional isomers​

Explanation:

i hope it will help

A 18.0 L gas cylinder is filled with 6.20 moles of gas. The tank is stored at 33 ∘C . What is the pressure in the tank?
Express your answer to three significant figures and include the appropriate units.

Answers

Answer:

8.65 atm

Explanation:

Using ideal law equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas law constant (Latm/molK)

T = temperature (K)

According to the information given in this question;

V = 18.0 L

n = 6.20 moles

R = 0.0821 Latm/molK

T = 33°C = 33 + 273 = 306K

P = ?

Using PV = nRT

P × 18 = 6.20 × 0.0821 × 306

18P = 155.76

P = 155.76/18

P = 8.65 atm

cuales son las caracteristicas de el livermorio

Answers

Answer:

Livermorium is a radioactive, artificially produced element about which little is known. It is expected to be a solid and classified as a metal. It is a member of the chalcogen group. Livermorium has four isotopes with known half-lives, all of which decay through alpha decay

Hydrogen chloride decomposes to form hydrogen and chlorine, like this:

2HCl(g) + H2(g) â Cl2(g)

Also, a chemist finds that at a certain temperature the equilibrium mixture of hydrogen chloride, hydrogen, and chlorine has the following composition:

compound pressure at equilibrium
HCl 84.4 atm
H2 77.9 atm
Cl2 54.4

Required:
Calculate the value of the equilibrium constant for this reaction. Round your answer to significant digits.

Answers

Solution :

Given :

Partial pressure of HCl, [tex]$P_{HCl}$[/tex] = 84.4 atm

Partial pressure of [tex]H_2[/tex], [tex]$P_{H_2}$[/tex] = 77.9 atm

Partial pressure of [tex]Cl_2[/tex], [tex]$P_{Cl_2}$[/tex] = 54.4 atm

Reaction :

[tex]$2HCl (g) \leftrightharpoons H_2(g) + Cl_2(g)$[/tex]

Using equilibrium concept,

[tex]$k_p=\frac{(P_{H_2})(P_{Cl_{2}})}{(P_{HCl})^2}$[/tex]

[tex]$k_p=\frac{77.9 \times 54.4}{(84.4)^2}$[/tex]

[tex]$k_p=0.594$[/tex]

[tex]k_p=0.59[/tex]  (in 2 significant figures)

or [tex]k_p=5.9 \times 10^{-1}[/tex]

why is repetition important in science?

Answers

Answer:

the repetition principle is important in scientific research, because the observational indexes are random variables,which requires a certain amount of samples to reveal their changing regularity

repeating something as in a meaning of a word helps us not only remember but have it stuck in our brain. My science teacher in 10th made us rewrite our vocab everyday until all of us knew it. When it came to test taking it was so much easier when I thought of the word. Repetition is so important in science to not only get you to understand the meaning of something but help you remember it.

c6h5-c=o-ch3 + br2/oh

Answers

Explanation:

here's the molecule you were looking for

How to prepared sodium chloride solution.​

Answers

Explanation:

Dissolve 93.52g of NaCl in about 400mL of distilled water, then add more water until final volume is 800mL. If starting with a solution or liquid reagent: When diluting more concentrated solutions, decide what volume(V2) and molarity (M2) the final soluble should be.

Analyze the data and determine the actual concentration of calcium chloride in the solution. Show all calculations and report in % wt/v concentration.
Known; Mass of CaCl2 present in original solution, based on actual yield= 1.77g moles
CaCl2 present in original solution, based on actual yield= 1.77g/molar mass of CaCl2=1.77g/110.98g/mol=0.016 moles
Total Volume of solution =V, which is 80ml

Answers

Answer:

2.21% wt/v

Explanation:

The mass/volume percentage, %wt/v, is an unit of concentration used in chemistry defined as 100 times the ratio of the mass of solute in g (In this case, CaCl2 = 1.77g) and the volume of solution in mL = 80mL

The %wt/v of this solution is:

%wt /v = 1.77g / 80mL * 100

%wt/v = 2.21% wt/v

how do elasticity ang flexibility differ?

Answers

Answer:

the object will regain its original form as soon as the deforming force is removed. ... Flexibility means the object is just easily deformed, and will stay that way.

Explanation:

who much the velocity of a body when it travels 600m in 5 min​

Answers

Answer:

2 m/s

Explanation:

Applying the formulae of velocity,

V = d/t............. Equation 1

Where V = Velocity of the body, d = distance, t = time

From the question,

Given: d = 600 m, t = 5 minutes = (5×60) = 300 seconds.

Substitute these values into equation 1

V = 600/300

V = 2 m/s.

Hence the velocity of the body when it travels is 2 m/s

Do the tests performed to identify DNA exclude the presence of RNA?

Answers

DNA and RNA can also be ISOLATED from the same biological sample.

So the answer is no, both DNA and RNA are together.

Answer:

so the answer is no

both DNA and RNA are together.

Explanation:

DNA and RNA can also be ISOLATED from the same. biological sample

What is the source of energy stored by ATP in cells?
Answers

A.
oxidation of biological compounds

B.
reduction of biological compounds

C.
synthesis of biological compounds

D.
polymerization of biological compounds

Answers

Answer:

I think C (synthesis of biological compounds

Explanation:

have a nice day

uses of rare or inert gases

Answers

Explanation:

noble gases are useful let's take for instance helium which is used in balloons. they are used to form inert atmosphere and they are used also to deter chemical reaction.

Hypercalcemia sign and symptoms severe symptoms

Answers

Answer:

Hypercalcemia can cause stomach upset, nausea, vomiting and constipation. Bones and muscles. In most cases, the excess calcium in your blood was leached from your bones, which weakens them. This can cause bone pain and muscle weakness.

Some symptoms are:

Fatigue, bone pain, headaches.

Nausea, vomiting, constipation, decrease in appetite.

Forgetfulness.

Lethargy, depression, memory loss or irritability.

Muscle aches, weakness, cramping and/or twitches.

explain in details how triacylglycerol have an advantage over carbohydrates as stored fuel

Answers

Answer:

As stored fuels, triacylglycerols have two significant advantages over polysaccharides such as glycogen and starch. The carbon atoms of fatty acids are more reduced than those of sugars, and oxidation of triacylglycerols yields more than twice as much energy, gram for gram, as that of carbohydrates.

Explanation:

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