Which substance has Delta.Hf defined as 0 kJ/mol? H2O (s) Ne (l) F2 (g) CO2 (g)

Answers

Answer 1

Answer:

F2 (g)

Explanation:

Edg 2021

Answer 2

Answer:

F2 g

Explanation:


Related Questions

At a constant temperature of 30 °C, an ideal gas occupies 2.78 Liters at a pressure of 1.27 atm. What will be the volume (L) at a pressure of 3.95 atm?

Answers

Answer:

[tex]V_2=0.894L[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to solve this problem by using the Boyle's law for an inversely proportional relationship between pressure and volume at constant temperature, as described in the problem statement:

[tex]P_2V_2=P_1V_1[/tex]

Thus, we solve for V2, final volume, to obtain the following result:

[tex]V_2=\frac{P_1V_1}{P_2} \\\\V_2=\frac{1.27atm*2.78L}{3.95atm}\\\\V_2=0.894L[/tex]

Regards!

what is the [H+] and [OH-] of a 3.5 M HCIO3 solution?

Answers

Answer: H+ ia helyuim

explinanation: Hope this helped!!

Determine the number of significant digits in each number and list the specific significant digits. 1. 306,000 2. 0.0073 3. 39.9999 4. 25.00 5. 40,000,021 6. 45,250.0 7. 0.00011 8. 420.030700

Answers

Answer:

1. 306,000: three significant figures because the last three zeros are not preceded by a decimal point.

2. 0.0073: two significant figures because the the leftmost zeros are not significant.

3. 39.9999: six significant figures because all these numbers are nonzero digits.

4. 25.00: four significant figures because right-handed zeros, after a decimal point, are significant.

5. 40,000,021: eight significant figures because intermediate zeros are significant.

6. 45,250.0: six significant figures because al the zeros are to the right of the nonzero digits.

7. 0.00011: two significant figures as well as #2.

8. 420.030700: nine significant figures because all the zeros are to the right of the first nonzero digits and after the decimal point.

Explanation:

Hello there!

In this case, by considering the given numbers, we can proceed as follows, by keeping in mind the rules for assigning significant figures:

1. 306,000: three significant figures because the last three zeros are not preceded by a decimal point.

2. 0.0073: two significant figures because the the leftmost zeros are not significant.

3. 39.9999: six significant figures because all these numbers are nonzero digits.

4. 25.00: four significant figures because right-handed zeros, after a decimal point, are significant.

5. 40,000,021: eight significant figures because intermediate zeros are significant.

6. 45,250.0: six significant figures because al the zeros are to the right of the nonzero digits.

7. 0.00011: two significant figures as well as #2.

8. 420.030700: nine significant figures because all the zeros are to the right of the first nonzero digits and after the decimal point.

Regards!

Question:
What is the molar concentration of 1.29 mol of KCL dissolved in 350 mL of solution?

Answers

Answer:

M = 3.69 M.

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to calculate the molar concentration of the 1.29 moles of KCl in 350 mL of solution by recalling the mathematical definition of molarity as the division of the moles by the volume in liters, in this case 0.350 L; thus, we proceed as follows:

[tex]M=\frac{1.29mol}{0.350L}\\\\M=3.69M[/tex]

Which gives molar units, M, or just mol/L.

Regards!

Give an example that illustrates the importance of chirality in a named biological molecule.​

Answers

Answer:

Chirality is a particularly important concept in biology, because cells are mostly composed of chiral molecules. Small chiral molecules such as amino acids and sugars (figure 1, top) are the building blocks of larger molecules, such as proteins and nucleic acids, which are also chiral

Star
Planet
*
As the planet makes one completer revolution around the star, starting at the position shown the gravitational attraction between the star
and the planet will
A Continually decrease
3 Decrease, then increase
increase then decrease
Romain the same
RI
12.20 AM
618/2001

Answers

Answer:

according to the path shown in the figure it will start decreasing then again it will start increasing when the path will be nearer to the star.

Reason is gravitation force is indirectly proportional to the distance.

So, option B. decrease then increase is correct

What’s the answer to the question

Answers

Answer: B

Explanation: im pretty sure my teacher mentioned something about N--h bonds are non polar

Answer:

C

Explanation:

6. What happens to energy during the formation of a solution?

It is released or absorbed.

It is only absorbed.

It is only released

It is nelther released nor absorbed.​

Answers

Answer:

it is released and absorbed:)

as the temperature of a chemical in this gas phase is increased, the rate of the reaction increases because

Answers

Answer:

An increase in temperature typically increases the rate of reaction. An increase in temperature will raise the average kinetic energy of the reactant molecules. Therefore, a greater proportion of molecules will have the minimum energy necessary for an effective collision

How many moles of KCl are in
28g of KCl?

Answers

Answer:

0.38 moles KCl

Explanation:

(28 g KCl) / (74.55 g/mol KCl) = 0.38 moles KCl

Answer:

There are 0.38 moles of KCI in

28g of KCI.

Explanation:

This maybe correct.

2) Gay-Lussac's law shows a direct relationship between temperature and
O moles
pressure
O volume
O density

Answers

Answer:

The correct option is (b) "pressure".

Explanation:

Gay-Lussac's law states that the pressure of an ideal gas is directly proportional to its temperature at constant mass and volume.

Mathematically, Gay-Lussac's law is as follows :

[tex]P=kT[/tex]

or

[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]

Hence, the correct option is (b) "pressure".

After being exposed to fire ant venom, crazy ants that were treated with formic acid has a significantly greater survival rate than those treated with a water-based control. In this experiment, these results suggested that:___________

Answers

Answer:

After being exposed to fire ant venom, crazy ants that were treated with formic acid has a significantly greater survival rate than those treated with a water-based control. In this experiment, these results suggested that:

Explanation:

That means formic acid increases its rate of survival.

So, formic acid acts in both ways as offensive and defensive ways to crazy ants.

20. What is an irreversible change?

Answers

Answer:

A change is called irreversible if it cannot be changed back again. For example you cannot change a cake back into its ingredients again. Irreversible changes are permanent.

Explanation:

Hope this helps!! :))

A change is called irreversible if it cannot be changed back again. In an irreversible change, new materials are always formed.

What is the mass of Na2CO3 required to make a
500 mL standard solution of 0.400 mol/L Na2CO3?
a. 212 g
b. 23.4 g
c. 25.8 g
d. 27.39

Answers

Answer:

21.2 g

Explanation:

Step 1: Given data

Molar concentration of the solution (C): 0.400 mol/LVolume of solution (V): 500 mL (0.500 L)

Step 2: Calculate the moles of Na₂CO₃ (solute) in the solution

We will use the definition of molarity.

C = moles of solute / liters of solution

moles of solute = C × liters of solution

moles of solute = 0.400 mol/L × 0.500 L = 0.200 mol

Step 3: Calculate the mass corresponding to 0.200 moles of Na₂CO₃

The molar mass of Na₂CO₃ is 105.99 g/mol.

0.200 mol × 105.99 g/mol = 21.2 g

Arrange the following molecules in order of decreasing polarity of their bonds.

a. PBr3
b. SF2
c. H2O
d. NCl3

Answers

Answer:

SF2 > H2O > PBr3 > NCl3

Explanation:

Compare the electronegativity values for the atoms and classify the nature of the bonding based on the electronegativity difference.

P has an electronegativity of 2.1, while Br has an electronegativity of 2.96. The difference is 0.86, indicating that these atoms will form covalent bonds.

S has an electronegativity of 2.58 while F has an electronegativity of 4.0. The difference is 1.42, indicating that these atoms will form polar covalent bonds.

O has an electronegativity of 3.5 while H has an electronegativity of 2.1. The difference is 1.4, indicating that these atoms will form polar covalent bonds.

N has an electronegativity of 3.04, whereas Cl has an electronegativity of 3.5. This difference of 0.46 indicates that these atoms will form covalent bonds.

We know that the greater the electronegativity, the higher the polarity. In decreasing order of polarity, we have:

SF2 > H2O > PBr3 > NCl3

The chemical equation of the reaction between Hydrogen and Oxygen is given below
H2 + O2 → H2O
(a) Write down the reactants and product of this reaction
(b) This chemical equation is not balanced . Why?
(c) Balance the given equation
9. Consider the given unbalanced reaction
Na + O2 → Na2O
(a) Find out the mono atomic and diatomic molecules in this equation
(b) What is the chemical compound present in this equation
(c) Balance the given equation

Answers

Answer:

1. a. The reactants are H₂ and O₂; The product is H₂O

b. The equation is not balanced because the number of atoms of the elements reacting is not equal to the number of atoms produced. 2 atoms of oxygen reacted but only one atom of oxygen is produced.

c. 2 H₂ + O₂ ---> 2 H₂O

2. a. The monotonic molecule is the sodium molecule, Na, since itnis made up of only one atom in its molecule.

The diatomic molecule is oxygen molecule, O₂, since it is made up of two atoms in its molecule.

b. The chemical compound present is sodium oxide, Na₂O

c. 4 Na + O₂ ---> 2 Na₂O

Explanation:

In a chemical reaction, the reactants are the elements or compounds which are converted to a new substance whichnis known as the product. The products are the new substances formed from the reactants.

In the given equation of reaction below;

H₂ + O₂ ---> H₂O

a. The reactants are H₂ and O₂; The product is H₂O

b. The equation is not balanced because the number of atoms of the elements reacting is not equal to the number of atoms produced. 2 atoms of oxygen reacted but only one atom of oxygen is produced.

c. 2 H₂ + O₂ ---> 2 H₂O

2. Given the reaction equation below:

Na + O₂ ---> Na₂O

a. The monotonic molecule is the sodium molecule, Na, since it is made up of only one atom in its molecule.

The diatomic molecule is oxygen molecule, O₂, since it is made up of two atoms in its molecule.

b. The chemical compound present is sodium oxide, Na₂O since itconsists of two chemically combined elements, sodium and oxygen.

c. 4 Na + O₂ ---> 2 Na₂O

A student obtains a beaker containing a solution that is determined to have a hydrogen ion
concentration (H+) of 6.7x10-14. Based on this information, please answer the following
questions:
a) What is the pH of the solution?
b) is the solution acidic, neutral or basic?

Answers

Answer:

pH = 13.1

Basic

Explanation:

Step 1: Given data

Hydrogen ion concentration ([H⁺]): 6.7 × 10⁻¹⁴ M

Step 2: Calculate the pH of the solution

We will use the definition of pH.

pH = -log [H⁺]

pH = -log 6.7 × 10⁻¹⁴ = 13.1

When pH < 7, the solution is acid.When pH = 7, the solution is neutral.When pH > 7, the solution is basic.

Since pH > 7, the solution is basic.

For the balanced chemical reaction
>
C4H2OH + 602 > 4CO2 + 5H20
if you want to make 100 molecules of CO2, how many molecules of O2 will you need? Answer with a number only.
ITS

Answers

Answer:

150

Explanation:

C₄H₂OH + 6O2 → 4CO2 + 5H₂O

We can find the equivalent number of O₂ molecules for 100 molecules of CO₂ using a conversion factor containing the stoichiometric coefficients of the balanced reaction, as follows:

100 molecules CO₂ * [tex]\frac{6moleculesO_2}{4moleculesCO_2}[/tex] = 150 molecules O₂

150 molecules of O₂ would produce 100 molecules of CO₂.

The Kc for the following is 5.0 at 100 degrees Celsius.
If an equilibrium mixture contains 0.53 M NO2 what is the molar concentration of N2O4?

Answers

Answer:

1.40M = [N2O4]

Explanation:

Based on the reaction:

2NO2(g) ⇄ N2O4(g)

Kc is defined as:

Kc = 5.0 = [N2O4] / [NO2]²

Where [] are the concentrations in equilibrium of each gas

As the equilibrium concentration of NO2 is 0.53M:

5.0 = [N2O4] / [0.53]²

5.0 = [N2O4] / [0.2809]

5.0*0.2809 = [N2O4]

1.40M = [N2O4]

What is a successful outcome for using a scientific method?

Answers

develop a theory. develop a hypothesis. support a hypothesis

The engineering process defines the steps engineers take to create
technology. Which of these describes these steps in the correct order?
O A. Identifying a problem, making a solution, testing the solution,
mass production, making improvements
O B. Identifying a need, researching the background of that need,
making a plan to meet the need, doing the work, evaluating the
results, looking for improvements
C. Identifying a problem, testing various solutions, researching side
effects of each solution, choosing a solution, looking to improve
the solution, planning how to test the solution
D. Identifying a problem, brainstorming solutions, researching the
background of each solution, testing solutions, choosing a
solution, production, making future improvements

Answers

Answer:

A

Explanation:

The processes engineers take to build technology are outlined by the engineering process, which is defined as identifying a need, learning more about it, making a plan to meet it, putting into practice, evaluating the results, and looking for improvements. So, the correct option is B.

What is an Engineering process?

Process engineering is described as the interpretation and application of the basic natural laws and principles that enable people to convert energy and materials into goods that are beneficial to society on an industrial scale.

The engineering process, which is defined as identifying a need, learning more about it, creating a plan to address it, putting the plan into practice, reviewing the outcomes, and seeking for improvements, provides an overview of the procedures engineers use to create technology.

Therefore, the correct option is B.

Learn more about Engineering process, here:

https://brainly.com/question/10175918

#SPJ7

what can a wave be described as

Answers

Answer:

wavy, a feel of water, smooth and costy

Explanation:

What is the name of this compound?

Answers

Answer:

THERE IS NOTHING MENTION HERE HOW CAN ANYONE KNOW ABOUT IT?]

Explanation:

HELP PLZ!!! 37. Which of the following most accurately describes what the pH scale measures?
the strength of a compound.
the strength of a base
th oncentration of acids and bases.
O
the concentration of an acid

Answers

Teri maa ka bhosda bosda bosda

You want to test how the mass of a reactant affect the speed of a reaction which of the following is an example of a controlled experiment to test this

Answers

Answer:A

Explanation:

what will happen if atom hit earth with speed of light?​

Answers

Answer:

A little atom will leave a big hole and a big atom cant travel that fast

Explanation:


A 200. gram sample of a salt solution contains 0.050 grams of NaCl. What is the concentration of the
solution in parts per million (ppm)?

Answers

Answer:

2.5 × 10² ppm

Explanation:

Step 1: Given data

Mass of NaCl: 0.050 gMass of the sample: 200. g

Step 2: Convert 0.050 g to μg

We will use the conversion factor 1 g = 10⁶ μg.

0.050 g × 10⁶ μg/1 g = 5.0 × 10⁴ μg

Step 3: Calculate the concentration of NaCl in ppm

The concentration of NaCl in ppm is equal to the micrograms of NaCl per gram of the sample.

5.0 × 10⁴ μg NaCl/200. g = 2.5 × 10² ppm

Answer:250 ppm

Explanation:

g .For each of the following disubstituted cyclohexanes, indicate whether the substituents in the two chair conformations would be both equatorial in one chair conformer and both axial in the other, or one equatorial and one axial in each of the two chair conformers. (a) Cis-1,2- (b) Trans-1,2- (c) Cis-1,3- (d) Trans-1,3- (e) Cis-1,4- (f) Trans-1,4-

Answers

Answer:

a) Both chairs conformers have one of its substituents in an axial position and the other in an equatorial position

b) One chair conformer has both its substituents in an axial position while the other chair has its substituents in an equatorial position

c) One chair conformer has both its substituents in an axial position while the other chair has its substituents in an equatorial position

d) Both chairs have one of its substituents in an axial position and the other in an equatorial position

e) Both chairs have one of its substituents in an axial position and the other in an equatorial position

(f) One chair conformer has both its substituents in an axial position while the other chair has its substituents in an equatorial position

Explanation:

Determine what the substituents would be

a) Cis-1,2-  : Both chairs conformers have one of its substituents in an axial position and the other in an equatorial position

b) Trans-1,2- : One chair conformer has both its substituents in an axial position while the other chair has its substituents in an equatorial position

c) Cis-1,3- : One chair conformer has both its substituents in an axial position while the other chair has its substituents in an equatorial position

d) Trans-1,3- : Both chairs have one of its substituents in an axial position and the other in an equatorial position

e) Cis-1,4- : Both chairs have one of its substituents in an axial position and the other in an equatorial position

(f) Trans-1,4- : One chair conformer has both its substituents in an axial position while the other chair has its substituents in an equatorial position

What is the mass of 0.1 mole of Cu(OH) 2 ?

Answers

Answer:

0.1

Explanation:

I know that because of the law of conservation of mass

Answer:9.6g

Explanation: thats the right answer

This is a quiz not a question from cambridge!


What is 2NaOH + Cl2→NaCl + NaOCl + H2O???



Answer::::


As products sodium chloride, sodium chlorate(I) and water are given. Hot concentrated Chlorine reacts with hot and concentrated sodium hydroxide solution to form sodium chloride and sodium chlorate.

Answers

Answer:

the answer is it's a balance chemical equation.

Explanation:

hope this helps u!!

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