Using standard heats of formation, calculate the standard enthalpy change for the following reaction.
2H2(g) + O2(g)
—>2H20(9)

Answers

Answer 1

Answer:

ΔH°r = -483.64 kJ

Explanation:

Let's consider the following balanced equation.

2 H₂(g) + O₂(g)  ⇒ 2 H₂O(g)

We can calculate the standard enthalpy change of the reaction (ΔH°r) using the following expression.

ΔH°r = ∑ΔH°f(p) × np - ∑ΔH°f(r) × nr

where

ΔH°f: standard heat of formation

n: moles

p: products

r: reactants

ΔH°r = ΔH°f(H₂O(g)) × 2 mol - ΔH°f(H₂(g)) × 2 mol - ΔH°f(O₂(g)) × 1 mol

ΔH°r = (-241.82 kJ/mol) × 2 mol - 0 kJ/mol × 2 mol - 0 kJ/mol × 1 mol

ΔH°r = -483.64 kJ


Related Questions

The symbol for free energy is
a. DG.
b. DS.
c. DT.
d. DH.

Answers

I think the answer is A but I’m not 100% sure

The sum of the kinetic energy and the potential energy of a particle is its

Answers

Answer:

he total mechanical energy E of a particle is defined as the sum of the kinetic and potential energies

Explanation:

Answer:

thermal energy

Explanation:

How many moles of C2H2 are required to produce 0.60 mol of H2O?
Express your answer to two significant figures and include the appropriate units.

Answers

Answer:

0.60 moles

Explanation:

From the reaction:

[tex]2C_2H_2 + 5O_2 \to 4CO_2+2H_2O[/tex]

From above, Only 2 moles of CH2CH2 are required to produce 2 moles of water (H_2O).

As such, 0.6 moles of H2O will require:

x (CH2CH2) × 2 moles of (H_2O)  = 0.6 moles (CH2CH2) × 2 mole of (H_2O)

x mole of  (CH2CH2) = 0.60 moles

0.6 moles of H2O will require 0.60 moles of CH2CH2

Part A. Classify each of these soluble solutes as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. Solutes Formula Nitric acid HNO3 Potassium hydroxide KOH Formic acid HCOOH Ethyl amine CH3CH2NH2 Sodium bromide NaBr Butanol C4H9OH Sucrose C12H22O11
Part B. Enter a molecular equation for the reaction that occurs between aqueous HBr and aqueous LiOH.

Answers

Answer:

1. Strong electrolytes = Nitric acid HNO3,Potassium hydroxide KOH, Sodium bromide NaBr

Weak electrolytes = Formic acid HCOOH Ethyl amine CH3CH2NH2, Butanol C4H9OH

Non-electrolyte = Sucrose C12H22O11

2. The reaction between aqueous HBr and aqueous LiOH is shown innthe equation below:

HBr + LiOH ----> NaBr + H₂O

Explanation:

Electrolytes are substances that when in molten state or in aqueous solution dissociate into ions both positively-charged and negatively-charged ions known as actions and anions, which are then able conduct electricity.

Strong electrolytes are aqueous or molten solutions of compounds which ionize completely to produce anions and actions. Ionic compounds such as organic salts, acids and bases are strong electrolytes.

Weak electrolytes only ionize partially, that is, they produce few ions. Some organic salts, acids and bases are weak elctrolytes

From the compounds given above;

Strong electrolytes = Nitric acid HNO3,Potassium hydroxide KOH, Sodium bromide NaBr

Weak electrolytes = Formic acid HCOOH Ethyl amine CH3CH2NH2, Butanol C4H9OH

Non-electrolyte = Sucrose C12H22O11

2. The reaction between aqueous HBr and aqueous LiOH is shown innthe equation below:

HBr + LiOH ----> NaBr + H₂O

Arrange in terms of increasing atomic radius. From smallest to largest.
S, F, Sr, Na, Ga

Answers

Answer:

F<S<Na<Ga<Sr

Explanation:

Atomic radius increased from the right of the periodic table to left, and from the top to the down

True or False: Without electromagnetic energy, the world as we know it would not exist.

Answers

True ,without electromagnetic energy there would be nothing

intermolecular dehydration of alkanols will gives what?​

Answers

Answer:

One way to synthesize alkenes is by dehydration of alcohols, a process in which alcohols undergo E1 or E2 mechanisms to lose water and form a double bond. The dehydration reaction of alcohols to generate alkene proceeds by heating the alcohols in the presence of a strong acid, such as sulfuric or phosphoric acid, at high tempera (sorry if this is wrong )

Which is an example of technology leading to a new discovery?
A. A truck is used to ship goods between two states.
B. A telescope shows that there is a planet past Neptune
C. An irrigation system is installed at a farm.
D. An antibiotic is used to treat an infection.​

Answers

Answer:

I think the answer would be B, because there is still stuff past the known exception of out private solar system. (and all the other options don't discover anything.)

The equation for the formation of ammonia from nitrogen and hydrogen is shown below. What is the formula for the equilibrium constant, Kc? {Hint, I’m just looking for letters/symbols, not numbers.}

H2(g) + N2(g) ⇌ NH3(g)

Answers

First, make sure to balance your equation.

3H2(g) + N2(g) ⇄ 2NH3(g)

Now, you can write your Kc expression. Remember that Kc is products over reactants, and the exponent for each product or reactant is based on its coefficient.

Kc = [NH3]^2 / [H2]^3[N2]

The reaction between nitrogen and hydrogen is called the Haber process. Kc for the reaction is the ratio of the concentration of ammonia to nitrogen and hydrogen.

What is the equilibrium constant?

An equilibrium constant, kc is the concentration proportion of the products to the concentration of the reactants raised by their respective coefficients.

The balanced chemical Haber process is given as:

[tex]\rm 3H_{2}(g) + N_{2}(g) \leftrightharpoons 2NH_{3}(g)[/tex]

Now, the equilibrium constant for the reaction can be given as:

[tex]\rm Kc = \rm \dfrac{[NH_{3}]^{2}}{[H_{2}]^{3}[N_{2}]}[/tex]

Therefore, the ratio of the concentration of ammonia to hydrogen and nitrogen gives the equilibrium constant.

Learn more about the equilibrium constant here:

https://brainly.com/question/15116048

The air bags in automobiles were once inflated by nitrogen gas generated by the rapid decomposition of
sodium azide, NaN3.

2 NaNz (s) 2 Na (s) + 3 N2 (g)

If an air bag has a volume of 53.4 L and is to be filled with nitrogen gas at a pressure of 1.07 atm and a
temperature of 23.7°C, how many moles of NaNz must decompose? You may assume the Ny behaves as
an ideal gas.

Answers

Answer:

1.57 mol NaN₃

Explanation:

2 NaN₃ (s) → 2 Na (s) + 3 N₂ (g)

First we use PV=nRT to calculate the number of N₂ moles that need to be produced:

P = 1.07 atmV = 53.4 Ln = ?R = 0.082 atm·L·mol⁻¹·K⁻¹T = 23.7 °C ⇒ 23.7 + 273.16 = 296.86 K

Inputing the data:

1.07 atm * 53.4 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 296.86

And solving for n:

n = 2.35 mol N₂

Finally we convert N₂ moles into NaN₃ moles, using the stoichiometric coefficients of the balanced reaction:

2.35 mol N₂ * [tex]\frac{2molNaN_3}{3molN_2}[/tex] = 1.57 mol NaN₃

As an FDA physiologist, you need 0.625 L of phosphoric acid acid / dihydrogen phosphate (H3PO4 (aq) / H2PO4 - (aq) ) buffer with a pH of 2.75. How do you prepare this solution from stock solutions of 1.0 M H3PO4 (formic acid) and 1.5 M NaOH

Answers

Answer:

0.4058L of 1.0M H3PO4

0.2192L of 1.5M NaOH

Explanation:

The pKa of the H3PO4 / H2PO4- buffer is 2.12

To solve this question we must use H-H equation for this system:

pH = pKa + log [H2PO4-] / [H3PO4]

2.75 = 2.12 +  log [H2PO4-] / [H3PO4]

0.63 = log [H2PO4-] / [H3PO4]

4.2658 = [H2PO4-] / [H3PO4] (1)

Where [] could be taken as the moles of each reactant

As you have H3PO4 solution, the reaction with NaOH is:

H3PO4 + NaOH → H2PO4- + Na+ + H2O

As you can see, both H3PO4 and H2PO4- comes from the same 1.0M H3PO4 solution

The moles of H3PO4 are:

[H3PO4] = Moles H3PO4 - Moles NaOH

And for H2PO4-:

[H2PO4-] = Moles NaOH added

Replacing in (1):

4.2658 = [Moles NaOH] / [Moles H3PO4 - Moles NaOH]

4.2658 Moles H3PO4 - 4.2658 moles NaOH = Moles NaOH

4.2658 Moles H3PO4 = 5.2658 moles NaOH (1)

In volume:

0.625L = Moles H3PO4 / 1.0M + Moles NaOH / 1.5M

0.625 = Mol H3PO4 + 0.6667 Moles NaOH (2)

Replacing (2) in (1):

4.2658 Moles H3PO4 = 5.2658 (0.625 - Mol H3PO4 / 0.6667)

4.2658 Moles H3PO4 = 5.2658 (0.625 - Mol H3PO4) / 0.6667

4.2658 Moles H3PO4 = 5.2658*(0.9375 - 1.5 mol H3PO4)

4.2658 Moles H3PO4 = 4.9367 -7.8983 mol H3PO4

12.1641 mol H3PO4 = 4.9367

Mol H3PO4 = 0.4058moles * (1L / 1.0moles) =

0.4058L of 1.0M H3PO4

And:

0.625L - 0.4058L =

0.2192L of 1.5M NaOH

Which process takes place in the conversion of iron into steel?​

Answers

Iron is changed into steel by blowing oxygen through the molten metal from the Blast Furnace. This oxidises the impurities in the molten metal. Carbon is a major impurity in Blast Furnace metal.

Why is Potassium called an alkali metal?

Answers

Answer:

Explanation: potassium (Na) has one electron in outer shell

And it donates it easily and can even reduce

Hydrogen gas from water. An alkaline solution containing

Hydroxide ions (OH-) is then formed

Answer:

Because

Explanation:

Potassium is called Alkali metal because Potassium forms oxides which dissolve in water to form Alkali

Click on an olive tree and read about it. Based on what you read, do you think the climate of Barcelona is very wet or rather dry? Explain.

Answers

Answer:

In the Autumn, Spring, and Winter, It is wet. In the Summer it is dry.

Explanation:

How are a tundra and a desert different?

A desert has a low level of precipitation and a tundra has a high level of precipitation.
A desert is wet year-round and a tundra is dry.
A tundra has a lower levels of humidity.
A tundra has lower average temperatures year-round.
i am giving brainlyest!!!!!!!

Answers

Answer:

A tundra has a lower average temperatures year-round.

tundra has lower temperatures year round

Which element is similar to the properties bromine?

Answers

Answer: Fluorine

Explanation: It belongs in the same group as Bromine

22.4 L is the volume of any gas regardless of atmospheric conditions.

O True

O False

Answers

This is false. One mole of a gas occupies 22.4 L at STP, which is taken to be 0°C (273 K) and 1 atm. If atmospheric conditions depart from these values, this assumption cannot be used.

Human blood contains a buffer of carbonic acid (H_2 CO_3) and bicarbonate anion (HC〖O_3〗^-) in order to maintain blood pH between 7.35 and 7.45, as a value higher than 7.8 or lower than 6.8 can lead to death. In this buffer, hydronium and bicarbonate anion are in equilibrium with carbonic acid. Furthermore, the carbonic acid in the first equilibrium can decompose into CO_2 gas and water, resulting in a second equilibrium system between carbonic acid and water. Because CO_2 is an important component of the blood buffer, its regulation in the body, as well as that of O_2 , is extremely important. The effect of this can be important when the human body is subjected to strenuous condition.
Carbonic acid buffer:
H_2 CO_3 (aq)+ H_2 O(l) ↔H_3 O^+ (aq)+HC〖O_3〗^- (aq)
1. Write the equilibrium constant expression K_c for the carbonic acid buffer in the blood.

Answers

Kc = [H3O+][HCO3-] / [H2CO3]

Remember that Kc is products over reactants. Also, you do not include liquid water in a Kc expression, since liquid water has no concentration.

A student left a sealed jar of water outside her home. Water can be a solid,
liquid, or gas. When she put it outside, the water was a solid. Twelve hours
later, the water had changed phase and was a liquid. What happened to
the water molecules?

a) Before the student left, the molecules were moving in place. After, the molecules were moving around each other.
b) Before the student left, the molecules were moving around each other. After, the
molecules were moving away from each other.
c) Before the student left, the molecules were moving around each other. After, the
molecules were moving in place.
d) Before the student left, the molecules were moving away from each other. After, the
molecules were moving around each other.

Answers

i think the answer is d) Before the student left, the molecules were moving away from each other. After, the

molecules were moving around each other.

I am sorry if the answer is wrong

If I place a pot of water over a fire (heat source), what will happen to the water?
None of the water will get warm.
All of the water will get warm.
Only the water on top will get warm.
Only the water closest to the source will get warm

Answers

Answer:

C. All of the water will get warm.

Explanation:

The water will get warm all together but slowly, eventually when it hits a certain high heated temperature it will start to boil.

Write the chemical symbols for three different atomic cations that all have 14 protons.

Answers

Explanation:

The symbols for three different cations with 14 protons are Si²⁺, Si⁴⁺, and Si³⁺. An element with 14 protons must be silicon, Si. Its electron configuration is [Ne] 3s²3p², so it could lose up to four valence electrons. The most likely cations are Si²⁺, Si⁴⁺, and Si³⁺ (or Si⁺)

What is the formula of compound formed from a calcium ion and As? Express your answer as a chemical formula

Answers

Answer:

its chemical formula is Ca3N2

Explanation:

hope it will help

What's the wavelength in meters of an electron traveling at 9.5 x 10^7 m/s? The mass of an electron is 9.11 x 10^-28 g.
Select one:
a. 7.66 x 10-15 m
b.7.66 x 10-12 m
c. 3.47 x 1027 m
d. 3.47 x 1030 m

Answers

Answer:

where:

• A is the wavelength in m.

• h = 6.626 x 10-34Js is Planck's

constant.

• m is the mass of the particle, such as the electron, in kg. The particle must have a mass for this relation to work.

• v is the forward velocity of the particle, in m/s.

Hence, the wavelength is:

6.626 x 10-34J.s

(9.1094 × 10 −³¹kg) (5 × 10³m/s)

We know that 1 J 1 kg. m²/s². So:

6.626 × 10-³4 g · m² / ø

9.1094 x 10 - 31) (5 x 105 m/s)

= 1.455 x 10-9 m

=

= 1.455 nm

Answer the following question by studying the given
structure of the stoma

1)Name the atoms of element
2)In which group of the periodic table do these element lie?​

Answers

Answer:

1) A. carbon B. oxygen

2) A. semi metal. B. Non- metal( gas)

How tightly particles are packed determines what state it takes.
True or False​

Answers

Answer:

True

Explanation:

tighter the molecules the slower it moves and the harder it gets

solid has very tight particles packed together

gas has its particles spread out

Which of the following is an example of a physical property?
A- Luminol reacting with blood stains to create a faint light
B- Bleach changing the color of a Ph test strip
C- The thickness of glass shards from a crime scene
D- Heroin turning purple when it is exposed to Marquis reagent

Answers

Answer:

The answer is C

Explanation:

It just makes the most sense to me

pls help i will mark as brainliest​

Answers

Answer:

ano po ito?? isa po ba itong story

7. The lowest whole-number ratio of the elements in a compound is called the
O empirical formula
O binary formula
O molecular formula
O representative formula

Answers

Answer: empirical formula is the answer. ur welcome.

Explanation:

Answer:

empirical formula

Explanation:

just took test

Can somebody please help me!!!!

Answers

Answer and Explanation:

The answer is Motion.

We can see that part of the image is blurry, which shows that the fish are moving fast. Moving = motion, so that means the fish has motion.

#teamtrees #PAW (Plant And Water)

Answer:

motion

Explanation:

Which of the following statements about C3 carbon fixation is true? a. C3 carbon fixation is an adaptation for plants exposed to high light intensity. b. C3 carbon fixation occurs in more plants than C4 carbon fixation. c. C3 carbon fixation is more common in areas of high temperatures than C4 carbon fixation. d. C3 carbon fixation occurs in the inner cells of a leaf rather than the entire leaf.

Answers

Answer: The answer is B

Explanation:

RiP BoZo. shout out to faze gabi staright up bopped potato girl.

Answer:

B

:D

Explanation:

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