From the following enthalpy changes,

2PCl3(l) → 2P(s) + 3Cl2(g) ∆H = -640 kJ
2P(s) + 5Cl2(g) → 2PCl5(s) ∆H = -886 kJ

calculate the value of ∆H for the reaction
PCl3(l) + Cl2(g) → PCl5(s) ∆H = ??

Answers

Answer 1

Answer:

∆H = -763kJ

Explanation:

Using Hess's law we can determine the ΔH of a reaction from the sum of similar reactions. Using the reactions:

(1) 2PCl3(l) → 2P(s) + 3Cl2(g) ∆H = -640 kJ

(2) 2P(s) + 5Cl2(g) → 2PCl5(s) ∆H = -886 kJ

The sum of (1)/2 + (2)/2 gives:

(1) / 2 = PCl3(l) → P(s) + 3/2Cl2(g) ∆H = -640 kJ/2 = -320kJ

(2) / 2 = P(s) + 5/2Cl2(g) → PCl5(s) ∆H = -886 kJ/2 = -443kJ

PCl3(l) + Cl2(g) → PCl5(s) ∆H = -320kJ - 443kJ =

∆H = -763kJ


Related Questions

Decide whether below chemical reaction iis an oxidation-reduction ("redox") reaction. If the reaction is a redox reaction, write down the formula of the reducing agent and the formula of the oxidizing agent.

3O2 + 4Fe → 2Fe2O3

Answers

Answer:

Explanation:

Yes , it is a redox reaction .

3O₂ + 4Fe → 2Fe₂O₃.

Increase of oxidation number shows oxidation and decrease of oxidation number shows reduction .

Neutral atoms have zero oxidation number .

O₂ and Fe are neutral atoms so their oxidation number is zero.

In Fe₂O₃ , charge on each Fe atom is + 3 . So its oxidation number is + 3 . Similarly charge on each of O in this compound is - 2 . So its oxidation number is -2 .

Oxidation number of Fe increases from 0 to + 3 . Hence it is oxidized .

Oxidation number of O decreases from 0 to  -2  . Hence it is reduced  .

Fe is oxidized by O ( oxygen ) so oxygen is the oxidizing agent .

O is reduced  by Fe ( iron  ) so iron  is the reducing agent .

Consider the incorrectly balanced combustion equation:
2C6H6 + 602 => 12CO2 + 6H2O
Select ALL elements that are not balanced.
Carbon
Hydrogen
Oxygen

Answers

Oxygen is balanced incorrectly.
The correct balanced equation: 2C6H6+15O2=12CO2+6H2O

Why Does the Moon Appear in the Daytime? ...
How Much Does the Sky Weigh? ...
How Much Does the Earth Weigh? ...
How Do Airplanes Stay in the Air? ...
Why Is Water Wet? ...
What Makes a Rainbow? ...
Why Don't Birds Get Electrocuted When They Land on Electric Wires?

Answers

The moon appears in the day time because the sun reflects off of it
The sky weighs 12,107,415,382,493,169,564 pounds
The earth weighs 1.317x10^24 pounds
Airplanes stay in the air because air going around the wings and the jets give it lift
Water is wet because it is touching another liquid (water)
Rainbows are created by light passing through water droplets and slowing down
Birds are tiny gods.
The other person sounds brainliest. Mark them brainliest

An atom or ion has 16 protons, 15 neutrons, and 17 electrons. Is it positive, negative, or
neutral? Why? What element is it?
I really need help on this so can someone tell me the answer please!

Answers

Its negative I think, if I remember correctly it is phosphorus-32....

opinion on the usage of identification of amine in daily life (medical, agriculture,etc)​

Answers

Answer:

The usage is explained below

Explanation:

Amines are identified from the use of the hinsberg reaction whereby the amine is mixed well with Hinsberg reagent and done in the presence of an aqueous alkali. In this reaction, the amine will attack the electrophile which will result in the chloride being displaced and the amides being generated.

The uses of identification of amines in daily life are;

- In agriculture, it serves as a good source of making herbicides as well as acting as emulsifiers.

- In medicine, it is used in the manufacture of some popular pain killers like demerol and morphine.

- In medicine, it is used in the manufacture of an anesthetic drug known as novocaine.

- In chemical industries, amines are used as lubricating oils and also as corrosion inhibitors in boilers.

How did we discover the Milky Way is a spiral galaxy?

Answers

A lot of data and making theories

Use Hess’s Law to calculate the heat of reaction for the following reaction:

2H2O2 → 2H2O +O2 ∆H=?
2H2 +O2 → 2H2O ∆H=-572 KJ
2H2O2 → 2H2 + 2O2 ∆H=376 KJ

Answers

2H2O2 ===> 2H2O + O2 ... TARGET EQUATION
We want to use the other equations that are given in order to make the target equation.
1) 2H2 + O2 ==> 2H2O ∆H = -572 kJ
2) H2 + O2 ==> H2O2 ∆H = -188 kJ

Reverse eq. 2 and multiply by 2 to get 2H2O2 on the left
2H2O2 ==> 2H2 + 2O2 ∆H = +376 kJ (change sign of ∆H and multiply by 2)
Copy eq.1
2H2 + O2 ==> 2H2O ∆H = -572
Add the two to get...
2H2O2 + 2H2 + O2 ==> 2H2 + 2O2 + 2H2O and cancel like terms on each side to get...
2H2O2 ==> 2H2O + O2 <==TARGET EQUATION
∆H = +376 kJ - 572 kJ = -196 kJ

The heat of reaction for the reaction 2H₂O₂ → 2H₂O +O₂ is -196 KJ

Calculating heat of reaction using Hess's law

From the question, we are to calculate the heat of reaction for the reaction

2H₂O₂ → 2H₂O +O₂               ∆H=?

Using Hess's law

Hess's Law of constant heat summation states that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes

From the given equations,

2H₂ +O₂ → 2H₂O                   ∆H= -572 KJ ---------- (1)

2H₂O₂ → 2H₂ + 2O₂              ∆H= 376 KJ ----------- (2)

Adding equations (1) and (2), we get

2H₂O₂ → 2H₂O +O₂               ∆H= -572 KJ + 376 KJ

2H₂O₂ → 2H₂O +O₂               ∆H= -196 KJ

Hence, the heat of reaction for the reaction 2H₂O₂ → 2H₂O +O₂ is -196 KJ.

Learn more on Calculating heat of reaction using Hess's law here: https://brainly.com/question/26491956

Which of the following is most accurate regarding the water cycle

Answers

Answer:

Is this question multiple choice if it is i can most likely answer it!

Explanation:

Convert 5,500 mg to kg. Show your work to receive full credit.

Answers

milligram to kilograms Conversion Table:
mg to kg
1.0 = 0.000001
2.0 = 0.000002
3.0 = 0.000003
4.0 = 0.000004
5.0 = 0.000005
6.0 = 0.000006
7.0 = 0.000007
8.0 = 0.000008
9.0 = 0.000009 milligram to kilograms
10 = 0.00001
20 = 0.00002
30 = 0.00003
40 = 0.00004
50 = 0.00005
100 = 0.0001
500 = 0.0005
1000 = 0.001
5000 = 0.005
kilograms to milligrams Conversion Table:
kg to mg
1.0 = 1000000
2.0 = 2000000
3.0 = 3000000
4.0 = 4000000
5.0 = 5000000
6.0 = 6000000
7.0 = 7000000
8.0 = 8000000
9.0 = 9000000
kilograms to milligrams
10 = 10000000
20 = 20000000
30 = 30000000
40 = 40000000
50 = 50000000
100 = 100000000
500 = 500000000
1000 = 1000000000
5000 = 5000000000
The milligram (British spelling: milligramme, abbreviation: mg) is a unit of mass in the SI system (metric system). One milligram is equal to one millionth of the kilogram (kg), which is the current SI (Metric system) base unit of mass. 1 milligram (mg) = 0.000001 kilogram (kg) = 0.001 grams (g) = 0.0000352739619 ounces (oz) = 0.00000220462262 pounds (lb).


1) A container holds 5,000 mL of CO2 at 742 atm. What will be the volume of the CO2 if the pressure is increased to 795 atm?​

Answers

Answer:

[tex]V_2=4667mL[/tex]

Explanation:

Hello there!

In this case, based on the given information, it is possible for us to provide an answer to this question by using the Boyle's law as directly proportional relationship between volume and pressure:

[tex]P_2V_2=P_1V_1[/tex]

Thus, by solving for the final volume, V2, as required, we obtain the following:

[tex]V_2=\frac{P_1V_1}{P_2} \\\\V_2=\frac{5,000mL*742atm}{795atm}\\\\V_2=4667mL[/tex]

Regards!

Use the standard reduction potentials located in the 'Tables' linked above to calculate the equilibrium constant for the reaction:
2H+(aq) + Cu(s) H2(g) + Cu2+(aq)
Hint: Carry at least 5 significant figures during intermediate calculations to avoid round off error when taking the antilogarithm. You may use the OWL references to find the values you may need in this question.

Answers

Answer:

3.3 * 10^-12

Explanation:

The balanced equation of the reaction is;

2H+(aq) + Cu(s) ---------> H2(g) + Cu2+(aq)

Hence two electrons were transferred so n=2

E°cell = E°cathode - E°anode

E°cell = 0 V - 0.34 V

E°cell = - 0.34 V

Then;

E°cell = 0.0592/n log K

Substituting values;

- 0.34 = 0.0592/2 log K

- 0.34/0.0296 = log K

-11.486 = log K

K = Antilog (-11.486)

K = 3.3 * 10^-12

Matter is anything that takes up space and hasA)mass.B)color.C)length.D)length and width

Answers

Answer:

A. Mass

Explanation:

If it takes up space it has to have mass. Not everything that is matter has a color, certain length or width.

It would probably be A

ajhsggsgvsbnsnnsnwbwbsbsvsccsvsbsbnsbwvvvdsvbs​

Answers

Answer:

thank uuuuuuu for freeeee pointssssss!!!!!..

Explanation:

hope it is helpful to you

A solution has a [OH−] of 1 x 10^−11 M. What is the [H3O+] of the solution?

Answers

Explanation:

Ionic product of water, Kw

[tex]Kw = [OH {}^{ - } ][H _{3} O {}^{ + } ] \\ 1.0 \times {10}^{ - 14} = (1 \times {10}^{ - 11} )[H _{3} O {}^{ + } ] \\ [H _{3} O {}^{ + } ] = \frac{(1.0 \times {10}^{ - 14}) }{(1 \times 10 {}^{ - 11}) } \\ ][H _{3} O {}^{ + } ] = 0.001 \: M[/tex]

This element has an oxidation number of -3 and it has 16 neutrons. What element is this room made of

Answers

Answer: Element is P, phosphor

Explanation:  Phosphor has oxidation number -III and it has 15 protons. So it is possible to have 16 neutrons. Other elements having oxidation number -III are N and As which can not have an isotope with 16 neutrons.

N2O3 → N2 + O2
Name the reactants in this reaction.
Name the products in this reaction.

Answers

[tex]\text{N}_{2}\text{O}_{3}=\text{nitrogen trioxide}\\\text{N}_{2}=\text{nitrogen}\\\text{O}_{2}=\text{oxygen}[/tex]

when does y’all’s summer start? I really curious bc mine start at may 16 when it usually start at may 26 ?

Answers

Mine starts in June but I wish it was in may school has been stressful lately but yea.

Answer:

we dont have summer breaks here

C5H12 + 8O2 —> 5CO2 +6 2O

Balance it

Answers

Answer:

it is already balanced

c5h12+8O2-->5CO2 +6h2o

Explanation:

4. Balance the following equation. Then determine the number of mols of Nitrogen formed given the values in a,b and c.
NH3 + O2 → N2 + H2O
a. 4 mol NH3

b. 4 mol N2

c. 4.5 mol O2

Answers

Answer:

4NH3 + 3O2 → 2N2 + 6H2O

a. 2 moles

b. 4 moles

c. 3 moles

Explanation:

a. 4 mol NH3

4NH3 + 3O2 → 2N2 + 6H2O

  4      :     3    :    2     :    6

  4                                        (mol)

⇒[tex]n_{N2}[/tex] = 4 × 2 ÷ 4 = 2

b. 4 mol N2

c. 4.5 mol O2

4NH3 + 3O2 → 2N2 + 6H2O

4      :     3    :    2     :    6

           4.5                          (mol)

⇒[tex]n_{N2}[/tex] = 4.5 × 2 ÷ 3 = 3

Give all possible, accurate, correct IUPAC names for the following compounds:

Answers

Answer:

A. 4-ethyl-hex-3,5-dien-2-ol.

B. 2-chloro-3-methyl-5-tert-butylphenol.

Explanation:

Hello there!

In this case, according to the given problems, it is possible to apply the IUPAC rules to obtain the following names:

A. 4-ethyl-hex-3,5-dien-2-ol because we have an ethyl radical at the fourth carbon and the beginning of the parent chain is on the Me (CH3) because it is closest to first OH.

B. 2-chloro-3-methyl-5-tert-butylphenol: because we start at the alcohol and have a chlorine atom on the second carbon, a methyl radical on the third carbon, a tert-butyl on the fifth carbon and the parent chain is benzene which is phenol as an alcohol.

Regards!

Which two come together to form an ionic bond?

a. a positive cation and a ngetaive cation
b. a positive cation and a negative anion
c. a positive cation and a positive anion
d. a positive anion and a negative anion

Answers

[tex]\huge \fbox \pink {A}\huge \fbox \green {n}\huge \fbox \blue {s}\huge \fbox \red {w}\huge \fbox \purple {e}\huge \fbox \orange {r}[/tex]

b. a positive cation and a negative anion

✏ Anions are negative in nature while cations are positive in nature. Together they come together by an attractive electrostatic force to form an ionic bond.

ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

[tex] \huge\blue{ \mid{ \underline{ \overline{ \tt ꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐ }} \mid}}[/tex]

For the reaction: 2H2 + O2 → 2H2O, how many grams of water are produced from

6.00 moles of H2?

Answers

Answer:

108 g

Explanation:

2H₂ + O₂ → 2H₂O

First we convert 6.00 moles of H₂ into moles of H₂O, using the stoichiometric coefficients of the reaction:

6.00 mol H₂ * [tex]\frac{2molH_2O}{2molH_2}[/tex] = 6.00 mol H₂O

Then we can convert 6.00 moles of H₂O into grams, using the molar mass of water:

6.00 mol H₂O * 18 g/mol = 108 g

The answer is 108 grams of water.

A saline solution has 1.9 grams of NaCI in 100 mL of solution. Calculate the molarity

Answers

Answer:  Molality = concentration = 0,33 mol/l

Explanation: Concentration c = n/V   and  n = m/M

M = 55,44 g/mol  and m = 1.9 g , V = 0.100 l

c = m/(MV)

Select the element(s) that will have ONE unpaired electron in the p orbital.

Ca

N

B

Ar

Br

Answers

Answer: The element B will have ONE unpaired electron in the p orbital.

Explanation:

The electronic configuration of each given element is as follows.

Atomic number of calcium (Ca) is 20.

Ca: [tex]1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2}[/tex]

Atomic number of nitrogen (N) is 7.

N: [tex]1s^{2} 2s^{2} 2p^{3}[/tex]

Atomic number of boron (B) is 5.

B: [tex]1s^{2} 2s^{2} 2p^{1}[/tex]

Atomic number of argon (Ar) is 18.

Ar: [tex]1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6}[/tex]

Atomic number of bromine (Br) is 35.

Br: [tex][Ar] 4s^{2} 3d^{10} 4p^{5}[/tex]

Therefore, boron is the only element that have one unpaired electron in the p-orbital.

Thus, we can conclude that element B will have ONE unpaired electron in the p orbital.

The pressure inside your
bike tire is 12.2 psi. What is this pressure if expressed in
millimeters of mercury (mm Hg)? (14.7 psi = 1 atm = 760mmHg)

Answers

Answer: The pressure 12.2 psi is expressed in millimeters of mercury (mm Hg) as 630.9221 mm Hg.

Explanation:

Given: Pressure = 12.2 psi

According to the standard conversion of units, 14.7 psi = 1 atm = 760mmHg.

Therefore, 1 psi equal to how many mm Hg is calculated as follows.

[tex]14.7 psi = 760 mm Hg\\1 psi = \frac{760}{14.7} mm Hg\\= 51.7149 mm Hg[/tex]

Hence, 12.2 psi will be converted into mm Hg as follows.

[tex]1 psi = 51.7149 mm Hg\\12.2 psi = 12.2 psi \times \frac{51.7149 mm Hg}{1 psi}\\= 630.9221 mm Hg[/tex]

Thus, we can conclude that the pressure 12.2 psi is expressed in millimeters of mercury (mm Hg) as 630.9221 mm Hg.

How many grams of product might form for the following reaction if 33.8 L of Oxygen gas is used in the following reaction? LiCl + O2 -> LiClO3

Answers

Answer:

91.41 g of LiClO₃.

Explanation:

We'll begin by calculating the number of mole of O₂ that occupied 33.8 L. This can be obtained as follow:

22.4 L = 1 mole of O₂

Therefore,

33.8 L = 33.8 L × 1 mole / 22.4 L

33.8 L = 1.51 mole of O₂

Next, the balanced equation for the reaction.

2LiCl + 3O₂ —> 2LiClO₃

From the balanced equation above,

3 moles of O₂ reacted to produce 2 moles of LiClO₃.

Therefore, 1.51 mole of O₂ will react to produce = (1.51 × 2)/3 = 1.01 mole of LiClO₃.

Finally, we shall determine the mass of 1.01 mole of LiClO₃. This can be obtained as follow:

Mole of LiClO₃ = 1.01 mole

Molar mass of LiClO₃ = 7 + 35.5 + (3×16)

= 7 + 35.5 + 48

= 90.5 g/mol

Mass of LiClO₃ =?

Mass = mole × molar mass

Mass of LiClO₃ = 1.01 × 90.5

Mass of LiClO₃ = 91.41 g

Thus, 91.41 g of LiClO₃ were obtained from the reaction.

Calculate the molarity of a solution that contains 5 mol of Li2O in 2.35 L of solution.

Answers

Answer:

2.13 M

Explanation:

To solve this problem we need to keep in mind the definition of molarity:

Molarity = moles / liters

As the problem gives us both the number of moles and the volume of solution, we can proceed to calculate the molarity:

Molarity = 5 mol / 2.35 LMolarity = 2.13 M

The answer is 2.13 M.

what is the valence number of HCO3-.​

Answers

-1 is the answer

So it requires one cation (i.e. positively charged ion). So according to this, its valency is -1. A hydrogen carbonate ion has the formula HCO3-, so the valency of a hydrogen carbonate ion is -1.

What is the freezing point in °C) of a 0.743 m
aqueous solution of KCI?
Enter your rounded answer with
3 decimal places.

Answers

Answer:

-0.276 Degrees C

Explanation:

kf of water is 1.86

Freezing point depression= m x kf x i

i= ions present ( K+ Cl-) 1=2

1.86x2X.743= .276

Since its freezinf point depression the freezing point will lower

so

0-.276= -.276

Answer: -2.764

Explanation:

Use the amount (mol) of solute and amount (mol) of solvent to calculate the mole fraction. An aqueous solution of ethanol, CH3CH2OH, has a concentration of 0.216 mol/L and has a density of 0.996 g/mL. What are the mass percent and mole fraction of CH3CH2OH in this solution

Answers

Answer:

%m/m = 0.9975%

Xₐ = 0.0039

Explanation:

In order to do this, we need various data. First to all, we need tje molecular mass of the ethanol. this can be obtained in handbooks, or simply taking the atomic weights of carbon (12 g/mol), Hydrogen (1 g/mol) and oxygen (16 g/mol) and summing those values:

MM C₂H₆O = (2*12) + (6*1) + (16*1) = 46 g/mol

Now, there is an expression that is commonly used to determine the molarity of a solution given the mass percent and density, and assuming of course, 1 liter of solution:

M = d * %m/m * 1000 / MM * 100     (1)

From here, we can solve for %m/m:

%m/m = M * MM * 100 / d * 1000

As the problem is not saying the volume of solution, we can easily assume we have 1 liter of solution. Therefore, the %m/m replacing the given data is:

%m/m = 0.216 *46 * 100 / 0.996 * 1000

%m/m = 0.9975%

To get the mole fraction, we first need to get the volume of solvent. From the density, we can get the mass of solution:

m = V * d

m = 1000 * 0.996 = 996 g of solution.

The mass of solute is:

m = 0.216 mol/L * 46 g/mol

m = 9.936 g/L, or simply we have 9.936 g of ethanol in 1 L of solution.

The mass of solvent:

solvent = 996 - 9.936 = 986.064 g

The molecular mass of water, so we can get the moles is 18 g/mol so:

moles water = 986.064 / 18 = 54.78

Finally the mole fraction:

Xₐ = 0.216 / (0.216 + 54.78)

Xₐ = 0.0039

Hope this helps

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