Propane (C3 H8 (g), Hf = –103.8 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2 , Hf = –393.5 kJ/mol ) and water (H2 O, Hf = –241.82 kJ/mol) according to the equation below. What is the enthalpy of combustion (per mole) of C3 H8 (g)? Use . –2,044.0 kJ/mol –531.5 kJ/mol 531.5 kJ/mol 2,044.0 kJ/mol

In the molecule CH3Cl, the sigma bond between Carbon and Chlorine is formed by the overlap of an s orbital from Carbon and a p orbital from Chlorine.

The type of orbitals that overlap to form the sigma bond between Carbon (C) and Chlorine (Cl) in CH3Cl are an s orbital from Carbon and a p orbital from Chlorine. This overlap can occur as the Carbon has its electronic configuration ending in 2s2 2p2, meaning it has access to one s orbital and three p orbitals. Chlorine, on the other hand, has its electronic configuration ending in 3s2 3p5, meaning it has a partially filled p orbital. This overlap produces a sigma bond, a covalent bond in which the electron density is concentrated in the region along the internuclear axis.

https://brainly.com/question/33779063

#SPJ12

The net ionic equation for the reaction of hydrochloric acid with sodium hydroxide is H⁺(aq) + OH⁻(aq) → H₂O(l), which shows the formation of water from hydrogen and hydroxide ions, ignoring the spectator ions sodium and chloride.

The net ionic equation for the reaction of hydrochloric acid with sodium hydroxide is as follows:

H⁺(aq) + OH⁻(aq) → H₂O(l)

In this equation, hydrochloric acid (HCl) dissociates into hydrogen ions (H⁺) and chloride ions (Cl⁻) when dissolved in water. Sodium hydroxide (NaOH) dissociates into sodium ions (Na⁺) and hydroxide ions (OH⁻).

The reaction between the hydrogen ions and hydroxide ions produces water (H₂O), and this is the net ionic equation for the reaction. Sodium (Na⁺) and chloride (Cl⁻) ions are present on both sides of the equation and they do not participate in the actual chemical change, so they are considered spectator ions and are not included in the net ionic equation.

An example of a Physical Change is:

C. sugar dissolving in water

Physical Change:

To determine which of the options represents a physical change, it's important to understand the difference between physical and chemical changes:

1) Physical Change: A change that affects one or more physical properties of a substance without altering its chemical composition. Examples include changes in state (like melting or dissolving), shape, or size.

2) Chemical Change: A change that results in the formation of new chemical substances. This often involves a reaction that alters the chemical structure of the original substance.

Let's analyze each option:

A. Wood Burning

Type: Chemical Change

Reason: Burning wood transforms it into ash, smoke, and gases, changing its chemical composition.

B. A Piece of Metal Rusting

Type: Chemical Change

Reason: Rusting involves the reaction of metal with oxygen, resulting in the formation of iron oxide, which is a different substance.

C. Sugar Dissolving in Water

Type: Physical Change

Reason: When sugar dissolves, it forms a solution but retains its chemical composition. No new substances are formed.

D. A Mineral Weathering to Form Another Mineral

Type: Chemical Change

Reason: Weathering often involves chemical reactions that change the mineral's composition.

The force of attraction that holds two atoms together is called a "chemical bond". True.

In the periodic table, dots around an element's symbol indicate the number of valence electrons in an atom. True.

True or false? The force of attraction that holds two atoms together is called a "chemical bond".

The correct answer is true. Chemical bond is the term used to describe the attractive force between atoms that holds them together in a molecule or compound. This force can be either ionic, where one atom transfers electrons to another, or covalent, where atoms share electrons.

True or false? In the periodic table, dots around an element's symbol indicate the number of valence electrons in an atom.

The correct answer is true. The dots, also known as electron dot diagrams or Lewis dot structures, represent the valence electrons of an atom. Valence electrons are the electrons in the outermost energy level of an atom and are responsible for the atom's chemical behavior and reactivity.

https://brainly.com/question/32180247

#SPJ11

A chemical bond is formed through the sharing or transfer of electrons between atoms. The dots around an element's symbol in the periodic table indicate the number of valence electrons in an atom.

The force of attraction that holds two atoms together is indeed called a chemical bond. This bond is formed through the sharing or transfer of electrons between atoms. When atoms share electrons, it is called a covalent bond, while when electrons are transferred, it forms an ionic bond.

In the periodic table, the dots around an element's symbol, known as the valence electrons, indicate the number of electrons in the outermost energy level of an atom. These electrons are involved in the formation of chemical bonds. The number of valence electrons determines the reactivity and chemical properties of an element.

https://brainly.com/question/6071754

#SPJ6

Answer : The moles of chlorine present in 140 grams of chlorine gas are 3.96 moles.

Explanation : Given,

Mass of [tex]Cl_2[/tex] = 140 g

Molar mass of [tex]Cl_2[/tex] = 70.9 g/mol

Formula used :

[tex]\text{Moles of }Cl_2=\frac{\text{Mass of }Cl_2}{\text{Molar mass of }Cl_2}[/tex]

Now put all the given values in this formula, we get:

[tex]\text{Moles of }Cl_2=\frac{140g}{70.9g/mol}[/tex]

[tex]\text{Moles of }Cl_2=1.98mol[/tex]

The number of moles of chlorine in [tex]Cl_2[/tex] = 2 × 1.98 = 3.96 mole

Therefore, the moles of chlorine present in 140 grams of chlorine gas are 3.96 moles.

To make 900 L of a 0.140 M aqueous solution of nitric acid, 2142 g or 2.142 kg of ammonia (NH3) is required, assuming a 100% yield in the chemical reaction.

The production of aqueous nitric acid involves a sequence of chemical reactions, the first of which is the combustion of ammonia: 4NH3(g) + 502(g) => 4NO(g) + 6H₂O(g). This means that 4 moles of ammonia (NH3) react to form 4 moles of nitric oxide (NO) which then further reacts to form nitric acid (HNO3).

Given that the molarity (M) of the solution is defined as the number of moles of solute per liter of solution, a 0.140 M solution of nitric acid means there are 0.140 moles of nitric acid per liter of solution. So, if we require 900.00 L of this solution, we will need 900*0.140 = 126 moles of nitric acid.

From the combustion reaction, we know that 1 mole of NH3 reacts to produce 1 mole of NO, and therefore 1 mole of HNO3. As a result, to achieve 126 moles of HNO3, we will need the same amount of NH3. Ammonia has a molar mass of approximately 17 g/mol, hence we require 126 moles * 17 g/mol = 2142 g or 2.142 kg of ammonia, assuming 100% yield in the reaction.

https://brainly.com/question/34442970

#SPJ11

You would need approximately 2142 grams of ammonia to produce 900.00 l of a 0.140 M solution of nitric acid, assuming 100% yield in the chemical reactions.

To determine how many grams of ammonia you would need to form 900.00 l of a 0.140 M solution of nitric acid, you must first understand that the main chemical reaction involved in the production of nitric acid is the combustion of ammonia (4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g)).

This balanced equation tells us that for every 4 moles of ammonia (NH3), 4 moles of nitric oxide (NO) are produced. Using the molarity of the nitric acid solution which is M = mol/L, we can calculate the moles of nitric acid to be 0.140 mol/l * 900.00 l = 126 mol. Assuming a 100% yield, we would need the same amount of moles of ammonia. The molar mass of NH3 is approximately 17 g/mol, so the mass of ammonia needed would be 126 mol * 17 g/mol = 2142 grams.

https://brainly.com/question/30218216

#SPJ11

Answer: Option (b) is the correct answer.

Explanation:

As it is known that both sodium and potassium are same group elements. Both of then belongs to group 1A.

Since, sodium is at 11th position in the periodic table and its atomic number is also 11. Therefore, electronic distribution of sodium is 2, 8, 1.

Similarly, potassium is placed at 19th position in the periodic table and its atomic number is 19. So, electronic distribution of potassium is 2, 8, 8, 1.

It is known that valence electrons are the electrons present in the outermost shell of an atom.

So, in a potassium atom there is only one valence electron is present.

Thus, we can conclude that potassium have 1 valence electron.

The autoionization constant Kw can be calculated at different temperatures, given a pH value, using the relationships between pH, pOH, the ion concentrations and Kw itself. For a neutral solution with a pH of 7.78, Kw can vary from standard values due to temperature changes.

The subject of your question is related to the pH level, the autoionization constant Kw, and the temperature of a solution. These topics fall under

Chemistry

at the high school level. To calculate the Kw for a solution with a pH of 7.78, we first need to understand the relationship between the pH and pOH values. The sum of the pH and pOH is always equal to 14, a fact known as the ion-product constant for water. Using this relationship, we can solve for the pOH value, which is 14 - pH.

In this case, the pOH value would be 14 - 7.78 = 6.22. Then, we obtain the concentrations of OH- and H3O+ ions from the expressions [H3O+] = 10^-pH and [OH-] = 10^-pOH. However, given this is a neutral solution, they should be equal. Substituting these values in Kw = [H3O+][OH-], we can calculate the value of Kw which should be near to 1.0 × 10^-14, the standard Kw value at 25 °C, but may vary due to the different temperature causing the change in pH.

https://brainly.com/question/31038353

#SPJ12

The value of Kw at this temperature is approximately 2.8 × 10⁻¹⁶ .

To find the value of Kw at a given temperature where the pH of a neutral solution is 7.78, calculate pKw (which is the sum of pH and pOH), and then use it to determine Kw.

We can use the formula:

Since pKw = pH + pOH:

Thus,

Hence, the value of Kw at this temperature is approximately 2.8 × 10⁻¹⁶

The IUPAC name for the given organic compound: CH₃CH₂CH(CH₃)CH₂CH₂OH is 3-methylhexan-2-ol.

IUPAC nomenclature refers to the chemical CH₃CH₂CH(CH₃)CH₂CH₂OH as 3-methylhexan-2-ol.

This term accurately describes its make-up: a six-carbon chain (hexane) with alcohol connected to the second carbon and a hydroxyl group (3-methyl) at the third carbon.

In order to precisely characterise organic compounds and enable unambiguous communication and identification of their structures, the IUPAC nomenclature adopts a systematic methodology.

Chemistry relies on this methodical naming strategy to describe and understand the precise atom arrangement within complicated compounds.

Thus, the answer is 3-methylhexan-2-ol.

For more details regarding IUPAC name, visit:

https://brainly.com/question/33646537

#SPJ12

Your question seems incomplete, the probable complete question is:

"Identify the IUPAC name for the following organic compound: CH₃CH₂CH(CH₃)CH₂CH₂OH. Be sure to use correct punctuation and formatting."

Answer:

pH=3.68

Explanation:

Hello,

At first, by knowing the 9.60-pH of the 0.070M solution of NaB, we can compute the Kb as the B contained into the NaB behaves as a base:

[tex]B^-+H_2O(l)<-->HB+OH^-[/tex]

Now, one can compute concentration of the OH ions because it is the same concentration of the HB based on the aforementioned chemical reaction:

[tex]pH=-log([H^+])\\\\ H^+=10^{-pH}=10^{-9.60}=2.51x10^{-10}\\OH^-=\frac{Kw}{[H^+]} =\frac{1x10^{-14}}{2.51x10^{-10}} =3.98x10^{-5}[/tex]

[tex][OH^-]=[HB]=3.98x10^{-5}M[/tex]

The Kb is then:

[tex]Kb=\frac{[HB][OH^-]}{[B^-]}=\frac{(3.98x10^{-5})^2}{0.070-3.98x10^{-5}} =2.264x10^{-8}[/tex]

After doing that, the Ka for the acid, taking into account its dissociation is:

[tex]HB<-->H^++B^-\\Ka=\frac{Kw}{Kb}=\frac{1x10^{-14}}{2.264x10^{-8}} =4.42x10^{-7}[/tex]

Based on the ICE conditions and table, one states the change during the dissociation of HB:

[tex]Ka=\frac{[H^+][B^-]}{[HB]}\\4.42x10^{-6}=\frac{x^2}{0.010-x} \\x=2.08x10^-4M[/tex]

Finally, the found value for x equals to the H+ concentration, so we compute the pH:

[tex][H^+]=2.08x10^{-4}\\pH=-log(2.08x10^{-4})\\pH=3.68[/tex]

Best regards.

Th pH of a 0.010 M solution of HB is 3.68 and value of Kb for HB is 2.26×10⁻⁸.

pH of any solution is define as the negative logarithm of the concentration of H⁺ ion in the solution.

Given that, pH = 9.6

9.6 = -log[H⁺]

[H⁺] = [tex]10^{-9.6}[/tex] = 2.51×10⁻¹⁰

Also we know that,

[H⁺][OH⁻] = 10⁻¹⁴

[OH⁻] = 10⁻¹⁴ / 2.51×10⁻¹⁰ = 3.98×10⁻⁵

Now we calculate the value of Kb for HB following the below equation:
                                     B⁻  +  H₂O(l)  →  HB  +  OH⁻

Initial:                        0.070                      0         0

Equilibrium:        0.070-3.98×10⁻⁵   3.98×10⁻⁵ 3.98×10⁻⁵

Kb = [3.98×10⁻⁵]² / (0.070-3.98×10⁻⁵)

Kb = 2.26 × 10⁻⁸

Also we know the relation Ka × Kb = 10⁻¹⁴

Ka = 10⁻¹⁴/2.26 × 10⁻⁸ = 4.42×10⁻⁷

For the below equation, value of Ka will be:

                              HB  ↔  H⁺  +  B⁻

Initial:                   0.010      0       0

Equilibrium:        0.010-x    x        x

Ka = x² / (0.010-x)

We can neglect the value of x as it is very small as compare to 0.010.

4.42×10⁻⁷ = x² / 0.010

x = 2.08×10⁻⁴ M

So, the pH of the HB solution is:

pH = -log(2.08×10⁻⁴)

pH = 3.68

Hence required pH is 3.68.

To know more about Kb & Ka, visit the below link:

https://brainly.com/question/26998

In terms of energy, microwaves have the lowest energy, followed by IR-B, and with IR-A having the highest energy.

The energy of electromagnetic radiation is inversely proportional to its wavelength. In other words, shorter wavelengths have higher energy, and longer wavelengths have lower energy. Let's compare the energy of microwaves, IR-B, and IR-A:

1. Microwaves have longer wavelengths compared to both IR-B and IR-A. Their wavelengths typically range from 1 mm to 1 m. Microwaves have lower energy compared to both IR-B and IR-A.

2. IR-B falls in the range of 1400 to 3000 nm (1.4 to 3.0 micrometers). It has shorter wavelengths compared to microwaves but longer wavelengths than IR-A. Therefore, IR-B has higher energy than microwaves but lower energy than IR-A.

3. IR-A falls in the range of 700 to 1400 nm (0.7 to 1.4 micrometers). It has shorter wavelengths compared to both microwaves and IR-B. As a result, IR-A has the highest energy among the three – higher than microwaves and IR-B.

So, in terms of energy, the order is:

IR-A > IR-B > Microwaves

Learn more on electromagnetic radiation here;

https://brainly.com/question/1408043

#SPJ3

The pH is neutral at the equivalence point during the titration of a strong acid with a strong base, resulting in a pH of 7.0.

The pH will be neutral at the equivalence point for a titration involving a strong acid and a strong base. At the equivalence point in such a titration, equimolar amounts of acid and base have been mixed, resulting in the formation of a salt and water, without excess hydronium (H+) or hydroxide (OH-) ions, which leads to a neutral pH of 7.0. The indicator chosen for this titration should change color at a pH of 7.0 to signify the end point.

For titrations involving a weak acid or weak base, the pH at the equivalence point is not neutral. In these cases, the resulting salt can affect the pH, either making the solution slightly acidic or basic. Therefore, the pH at the equivalence point for such titrations depends on the specific acid and base being used.

The carbon atom in difluoromethane (CH2F2), referred to as R-32, is surrounded by four electron domains, corresponding to its four bonds - two to hydrogen atoms and two to fluorine atoms.

In the molecule difluoromethane (CH2F2), there are four single bonds around the central carbon atom, namely, two to hydrogen atoms and two to fluorine atoms. Each of these bonds is considered an electron domain. Therefore, there are four electron domains around the carbon atom in this molecule.

https://brainly.com/question/31409913

#SPJ6

The molecular formula of the compound of sulfur and fluorine is [tex]\boxed{{{\text{S}}_2}{{\text{F}}_2}}[/tex].

Further Explanation:

Empirical formula:

It is atom’s simplest positive integer ratio in compound. It may or may not be the same as that of molecular formula. For example, empirical formula of disulfur dioxide is [tex]{\text{SO}}[/tex].

Molecular formula:

It is chemical formula that indicates the total number and kinds of atoms in molecule. For example, molecular formula of disulfur dioxide is [tex]{{\text{S}}_2}{{\text{O}}_2}[/tex]

Step 1: Mass of sulfur (S) and fluorine (F) is to be calculated. This is done by using equation (1).

Since the given compound contains only sulfur and fluorine. So the mass of sulfur is calculated as follows:

[tex]{\text{Mass of sulfur}}\left( {\text{S}} \right) = {\text{Mass of compound}} \times {\text{percentage of Sulfur}}[/tex]      ......(1)

The mass of the compound is 102.13 g/mol.

The percentage of sulfur is 62.79 %.

Substitute the values in equation (1).

[tex]\begin{aligned}{\text{Mass of sulfur}}\left( {\text{S}} \right) &= 102.13{\text{ g/mol}} \times 62.79{\text{ }}\%\\&= 102.13{\text{ g/mol}} \times \frac{{62.79}}{{100}}\\&= 64.13{\text{ g/mol}}\\\end{aligned}[/tex]

The mass offluorine (F) is calculated as follows:

[tex]{\text{Mass of fluorine}}\left( {\text{F}} \right) = {\text{Mass of compound}} - {\text{Mass of sulfur}}\left( {\text{S}} \right)[/tex]   ......(2)

Substitute 102.13 g/mol for mass of the compound and 64.13 g/mol for mass of sulfur in equation (2).

[tex]\begin{aligned}{\text{Mass of fluorine}}\left({\text{F}} \right) &= {\text{102}}{\text{.13 g/mol}} - {\text{64}}{\text{.13 g/mol}}\\&= 38{\text{ g/mol}}\\\end{aligned}[/tex]

Step 2: The number of sulfur (S) and fluorine (F) in the compound is to be calculated.

The formula to calculate the number of sulfur (S)atoms in the molecule is as follows:

[tex]{\text{Number of S}} = \dfrac{{{\text{Given mass of S}}}}{{{\text{Molar mass of S}}}}[/tex]                              ......(3)

The given mass of S is 64.13 g/mol.

The molar mass of S is 32 g/mol.

Substitute these values in equation (3).

[tex]\begin{aligned}{\text{Number of S}} &= \frac{{{\text{64}}{\text{.13 g/mol}}}}{{{\text{32 g/mol}}}} \\&\approx 2\\\end{aligned}[/tex]

The formula to calculate the number of fluorine (F) atoms in the molecule is as follows:

[tex]{\text{Number of F}} = \dfrac{{{\text{Given mass of F}}}}{{{\text{Molar mass of F}}}}[/tex]                      ......(4)

The given mass of F is 38 g/mol.

The molar mass of F is 19 g/mol.

Substitute these values in equation (4).

[tex]\begin{aligned}{\text{Number of F}} &= \frac{{{\text{38 g/mol}}}}{{{\text{19 g/mol}}}}\\&= 2\\\end{aligned}[/tex]

Hence the molecular formula of the given compound is [tex]{{\mathbf{S}}_{\mathbf{2}}}{{\mathbf{F}}_{\mathbf{2}}}[/tex].

Learn more:

1. Calculate the moles of ions in the solution: https://brainly.com/question/5950133

2. Calculate the moles of chlorine in 8 moles of carbon tetrachloride: https://brainly.com/question/3064603

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Stoichiometry of formulas and equations

Keywords: empirical formula, S, F, SF, S2F2, subscript, moles of F, moles of S, mass of S, mass of F and molecular formula.

Approximately 103.14 mL of concentrated HCl is necessary to make a 0.250 M HCl solution in a 5 L volume.

To determine the volume of concentrated HCl required to make a 0.250 M HCl solution in a 5 L volume, we can use the dilution formula:

[tex]\[ C_1V_1 = C_2V_2 \][/tex]

First, we need to ensure that all volumes are in the same unit, so we convert 5 L to milliliters:

[tex]\[ 5 \text{ L} \times 1000 \text{ mL/L} = 5000 \text{ mL} \][/tex]

Now we can plug the values into the dilution formula:

[tex]\[ (12.1 \text{ M})(V_1) = (0.250 \text{ M})(5000 \text{ mL}) \][/tex]

Solving for [tex]\( V_1 \):[/tex]

[tex]\[ V_1 = \frac{(0.250 \text{ M})(5000 \text{ mL})}{12.1 \text{ M}} \][/tex]

[tex]\[ V_1 = \frac{1250}{12.1} \text{ mL} \][/tex]

[tex]\[ V_1 \approx 103.14 \text{ mL} \][/tex]

Answer: The element is Strontium.

Explanation:

Atomic number is defined as the number of electrons or number of protons that are present in an element.

Atomic number = Number of protons = Number of electrons

If an element has a positive charge, it means that the electrons are lost which were earlier present.

Thus, the total number of electrons in the given element becomes = 36 + 2 = 38

And the element which has 38 electrons means that it has an atomic number of 38.

Hence, the element is Strontium.

The number of Hg atoms present in 1.0 ×10⁻¹⁰ mol of mercury is 6.022 × 10¹³.

Avogadro’s number can represent the number of particles in one mole of any substance. Generally, these particles can be molecules, atoms, ions, electrons, or protons, which depends upon the type of chemical reaction or their reactant and product.

The value of Avogadro’s number is approximately equal to 6.022 × 10²³ per mol.

Given, the number of moles of mercury (Hg) =  1.0 ×10⁻¹⁰ mol

The number of Hg atoms of mercury in one mole = 6.022 × 10²³ atoms

Then 1.0 ×10⁻¹⁰ mol of mercury will have atoms = 6.022 × 10²³ × 1.0 ×10⁻¹⁰

The number of atoms of mercury =  6.022 × 10¹³ Hg atoms

Therefore, the number of Hg atoms present in 1.0 ×10⁻¹⁰ mol of mercury is equal to  6.022 × 10¹³.

Learn more about Avogadro's number, here:

brainly.com/question/11907018

#SPJ2

In 2 moles of Na₃PO₄ the number moles of oxygen atom is c. 8.

To determine the number of moles of oxygen atoms in 2 moles of Na₃PO₄, we first need to understand the chemical formula of sodium phosphate (Na₃PO₄).

The chemical formula of sodium phosphate is Na₃PO₄.

Given that we have 2 moles of Na₃PO₄, we can calculate the total number of oxygen atoms present in these 2 moles by using the following steps:

1. Calculate the molar mass of Na₃PO₄:

2. Calculate the number of moles of oxygen atoms in 2 moles of Na3PO4:

Given that 1 mole of Na₃PO₄ contains 4 moles of oxygen atoms, we can set up a proportion:

1 mole of Na₃PO₄ / 4 moles of O = 2 moles of Na₃PO₄ / x moles of O

By cross-multiplying, we get:

Therefore, there are 8 moles of oxygen atoms in 2 moles of Na₃PO₄.

Correct question is: How many moles of oxygen atoms are in 2 moles of Na₃PO₄?

a. 3

b. 3

c. 8

d. 6

thx but it's actually 143

Answer:

B

Explanation: If it has a positive trait it will have more energy or more etc.  

The density of the unknown metal, calculated using the formula density = mass / volume with the given mass of 35.4 g and volume of 3.11 cm³, is 11.382 g/cm³.

To calculate the density of the unknown metal, you can use the density formula
which is density = mass / volume. Given that the mass of the metal is 35.4 g and the volume is 3.11 cm³, the calculation would be as follows:

Density = mass / volume
Density = 35.4 g / 3.11 cm³
Density = 11.382 g/cm³

Therefore, the density of the sample of the unknown metal is 11.382 g/cm³.