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Considering the Hess's Law,  the enthalpy change for the reaction is -136.8 kJ.

Hess's Law indicates that the enthalpy change in a chemical reaction will be the same whether it occurs in a single stage or in several stages. That is, the sum of the ∆H of each stage of the reaction will give us a value equal to the ∆H of the reaction when it occurs in a single stage.

In this case you want to calculate the enthalpy change of:

C₂H₄ + H₂ → C₂H₆

which occurs in three stages, with their corresponding enthalpies:

Equation 1: C₂H₄ + 3 O₂ → 2 CO₂ + 2 H₂O    ΔH = –1411 kJ

Equation 2:  C₂H₆ + 3 1/2 O₂ → 2 CO₂ + 3 H₂O     ΔH = –1560 kJ  

Equation 3: H₂ + 1/2 O₂ → H₂O     ΔH = - 285.8 kJ

Because of the way formation reactions are defined, any chemical reaction can be written as a combination of formation reactions, some going forward and some going back.

In this case, to obtain the enthalpy of the desired chemical reaction you need one C₂H₆ on product side and it is present in second equation on product side.  So, it is necessary to locate the C₂H₆ invert it. When an equation is inverted, the sign of delta H also changes.

Then, you know that three equations with their corresponding enthalpies are:

Equation 1: C₂H₄ + 3 O₂ → 2 CO₂ + 2 H₂O    ΔH = –1411 kJ

Equation 2:  2 CO₂ + 3 H₂O → C₂H₆ + 3 1/2 O₂     ΔH = 1560 kJ  

Equation 3: H₂ + 1/2 O₂ → H₂O     ΔH = - 285.8 kJ

Adding or canceling the reactants and products as appropriate, and adding the enthalpies algebraically, you obtain:

C₂H₄ + H₂ → C₂H₆     ΔH= -136.8 kJ

Finally, the enthalpy change for the reaction is -136.8 kJ.

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Weight is best defined as the force of gravity on an object (option C).

Weight is the force on an object due to the gravitational attraction between it and the Earth (or whatever astronomical object it is primarily influenced by).

Weight is different from mass being that weight is a dependent on the gravitational force of the object's habitation, however, mass is not.

For example, the mass of an object on Earth can be 10kg, however, the weight of the object is 100N because the gravitational force of the Earth is 10m/s².

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150 grams of NaOH is approximately equal to 2.256 x 10^24 particles of NaOH.

To convert grams of NaOH to particles of NaOH, we need to use the concept of molar mass and Avogadro's number. The molar mass of NaOH is calculated by adding the atomic masses of sodium (Na), oxygen (O), and hydrogen (H) together. It can be determined as follows:

Na: 22.99 g/mol

O: 16.00 g/mol

H: 1.01 g/mol

Molar mass of NaOH = (22.99 g/mol) + (16.00 g/mol) + (1.01 g/mol) = 40.00 g/mol

Now, we can use the molar mass to convert grams of NaOH to moles. Since 1 mole contains Avogadro's number (approximately 6.022 x 10^23) particles, we can determine the number of particles as follows:

150 g NaOH * (1 mol NaOH / 40.00 g NaOH) * (6.022 x 10^23 particles / 1 mol NaOH) ≈ 2.256 x 10^24 particles

It's important to note that this calculation assumes the substance is pure NaOH and that the molar mass and Avogadro's number are accurate.

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One structural difference between oligosaccharides and polysaccharides is the number of monosaccharide units they consist of. Oligosaccharides have a relatively small number of monosaccharide units (typically 3 to 10), while polysaccharides have a larger number of monosaccharide units (often hundreds or thousands).

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To calculate the entropy (ΔS), enthalpy (ΔH), and free energy change (ΔG) for the reaction under standard conditions, we can use the given values:

ΔH = ΣH(products) - ΣH(reactants)

= (-74.8 kJ/mol + 0 kJ/mol) - (-487.0 kJ/mol)

= 412.2 kJ/mol

ΔS = ΣS(products) - ΣS(reactants)

= (213.6 J/(mol K) + 0 J/(mol K)) - (159.8 J/(mol K))

= 53.8 J/(mol K)

ΔG = ΔH - TΔS

= 412.2 kJ/mol - (298 K) * (53.8 J/(mol K) / (1000 J/kJ))

= 412.2 kJ/mol - 16.0 kJ/mol

= 396.2 kJ/mol

Therefore, under standard conditions, the values for the reaction are:

ΔH = 412.2 kJ/mol

ΔS = 53.8 J/(mol K)

ΔG = 396.2 kJ/mol

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The layers that make up the Earth's atmosphere has unique properties that influence the kinds of wavelengths that are reflected, absorbed, or permitted to pass through to the planet's surface. Three layers are troposphere, stratosphere, and mesosphere.

The troposphere, the first layer closest to the surface of the planet, is where the majority of the planet's weather is found. The temperature in this layer drops with altitude, and it is made up of greenhouse gases like carbon dioxide and water vapor.

The stratosphere, which contains the ozone layer, is the next layer. The sun's dangerous UV light is absorbed by ozone, keeping it from reaching the surface of the Earth.

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The molar mass of the gas is 3.58 g/mol.

We can use the ideal gas law equation:

[tex]PV = nRT[/tex]

Where

We can rearrange the equation to solve for n:

[tex]n = PV/RT[/tex]

We know the following values:

P = 918 torr

V = 222 mL

R = 62.36 L torr/mol K

T = 57°C + 273 = 330 K

To solve for n, we can enter these numbers into the equation:

n = (918 torr)(222 mL)/(62.36 L torr/mol K)(330 K) = 0.0108 mol

Now, we can use the definition of molar mass to find the molar mass of the gas:

molar mass = mass/number of moles

We know the following values:

mass = 38.6 mg = 0.0386 g

n = 0.0108 mol

We can plug these values into the equation to solve for the molar mass

molar mass = 0.0386 g/0.0108 mol = 3.58 g/mol

Therefore, the molar mass of the gas is 3.58 g/mol.

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Explanation:

The balanced equation is

2  H2        +    02 ======> 2 H2 O

so it takes twice as many H2 moles as O2 to complete the reaction

  the chemist does not have enough  H2 (needs 8 moles)   , so H2 is the limiting reactant .

If you're attempting to synthesize 2 benzyl pentanoic acid from acetoacetic ester, keep in mind that you can do so fairly quickly by following these simplified instructions:

From its pungent free scent to its solid state at temperatures ranging from 118 120°C, acetoacetic ester (better known as ethyl acetoacetate) offers significant value for those working within organic synthesis.

As one of many potent ketones utilized by researchers around the globe its unique properties make it ideal for building complex molecules essential for modern medicine and more.

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The produce 1 mole of AgCl, we would have approximately 6.022 × 10^23 particles of silver chloride.

To determine the number of particles of silver chloride produced, we need to consider the balanced chemical equation and the stoichiometry of the reaction involved.

The balanced chemical equation for the formation of silver chloride (AgCl) is:

2 AgNO3 + NaCl → AgCl + 2 NaNO3

From the equation, we can see that two moles of silver nitrate (AgNO3) react with one mole of sodium chloride (NaCl) to produce one mole of silver chloride (AgCl).

To calculate the number of particles, we need to know the number of moles of silver chloride. Let's assume that we have 'x' moles of AgCl.

According to the balanced equation, the molar ratio between AgCl and AgNO3 is 1:2. So, if 'x' moles of AgCl are produced, then '2x' moles of AgNO3 must react.

Now, if we know the molar mass of AgCl, we can convert the moles of AgCl to particles using Avogadro's number (6.022 × 10^23 particles/mol).

To provide an accurate answer in 125 words, I'll need to make some assumptions. Let's assume we have 1 mole of AgCl. Then, the number of particles of AgCl would be:

1 mole AgCl × (6.022 × 10^23 particles/mol) = 6.022 × 10^23 particles.

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Complete Question

How many grams of silver chloride are produced from 5.0 g of silver nitrate reacting with an excess of barium chloride in the reaction

2AgNO3 +BaCl2 →2AgCl +Ba(NO3)2?

Answer:

the temperature increased

55.03 moles of KCI are produced when 6743 grams of [tex]KClO_{3}[/tex] decomposes

To determine the number of moles of KCl produced when 6743 grams of [tex]KClO_{3}[/tex] decomposes, we need to use the concept of molar mass and the balanced chemical equation.

First, let's calculate the molar mass of [tex]KClO_{3}[/tex]

The molar mass of potassium (K) is approximately 39.10 g/mol.

The molar mass of chlorine (Cl) is approximately 35.45 g/mol.

The molar mass of oxygen (O) is approximately 16.00 g/mol.

So, the molar mass of [tex]KClO_{3}[/tex] is:

(39.10 g/mol) + (35.45 g/mol) + (3 * 16.00 g/mol) = 122.55 g/mol.

Now, we need to calculate the number of moles of [tex]KClO_{3}[/tex]:

Number of moles = Mass / Molar mass

Number of moles = 6743 g / 122.55 g/mol = 55.03 mol.

According to the balanced chemical equation:

2[tex]KClO_{3}[/tex] -> 2 KCl + 3 O2,

we can see that for every 2 moles of [tex]KClO_{3}[/tex], we obtain 2 moles of KCl.

Therefore, the number of moles of KCl produced will be equal to the number of moles of [tex]KClO_{3}[/tex] since the ratio is 1:1. Thus, 55.03 moles of KCl will be produced.

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To calculate the root-squared error for ΔH, we need to consider the uncertainties associated with both the heat capacity (c) and the temperature change (T) in the equation.

Temperature change (T) = 3.30 ± 0.60 °C

Heat capacity (c) = 0.862 ± 0.012 kJ °C^(-1)

To calculate the root-squared error, we need to propagate the uncertainties using the formula:

(root-squared error)^2 = (partial derivative of ΔH with respect to c * error in c)^2 + (partial derivative of ΔH with respect to T * error in T)^2

The partial derivative of ΔH with respect to c = T

Error in c = 0.012 kJ °C^(-1)

The partial derivative of ΔH with respect to T = c

Error in T = 0.60 °C

Substituting the values into the formula:

(root-squared error)^2 = (T * error in c)^2 + (c * error in T)^2

= (3.30 °C * 0.012 kJ °C^(-1))^2 + (0.862 kJ °C^(-1) * 0.60 °C)^2

Calculating this expression:

(root-squared error)^2 ≈ (0.0396 kJ)^2 + (0.5172 kJ)^2

≈ 0.00157 kJ^2 + 0.2672 kJ^2

≈ 0.2688 kJ^2

Finally, taking the square root of the result:

root-squared error ≈ √(0.2688 kJ^2)

≈ 0.518 kJ

Therefore, the root-squared error for ΔH is approximately 0.518 kJ.

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Approximately 1.167 grams of the 25% (m/m) NaCl solution would contain 0.250 moles of sodium chloride.

To determine the mass of a 25% (m/m) sodium chloride (NaCl) solution containing 0.250 moles of sodium chloride, we need to consider the concentration and molar mass of NaCl.

The percentage (m/m) concentration indicates the mass of solute (NaCl) present per 100 grams of the solution. Therefore, a 25% (m/m) NaCl solution contains 25 grams of NaCl per 100 grams of the solution.

First, we calculate the mass of NaCl in the given solution:

Mass of NaCl = (25% / 100%) x Mass of solution

= (25 / 100) x Mass of solution

Next, we can determine the mass of the solution required to have 0.250 moles of NaCl using the molar mass of NaCl, which is approximately 58.44 g/mol.

Mass of NaCl = Moles x Molar mass

Mass of solution x (25 / 100) = 0.250 moles x 58.44 g/mol

Now, we can solve for the mass of the solution:

Mass of solution = (0.250 moles x 58.44 g/mol) / (25 / 100)

= 1.167 g

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Answer:

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Explanation:

Potassium has 4 energy levels and 1 valence electron.

The periodic table can tell you the number of valence electrons and the number of energy levels an atom has. The group number tells the number of valence electrons, while the period number tells the number of energy levels.

Both Ca(OH)₂ (calcium hydroxide) and NaOH (sodium hydroxide) are examples of strong bases.

A base is a substance that can accept protons (H) or donate hydroxide ions (OH) in a chemical reaction. strong bases completely dissociate in water, releasing hydroxide ions.

In the case of Ca(OH)₂, when it is dissolved in water, it dissociates into calcium ions and hydroxide ions  The hydroxide ions make it a strong base.

Similarly, NaOH, when dissolved in water, completely dissociates into sodium ions (Na+) and hydroxide ions (OH-), making it a strong base as well.

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13 atm

Ideal gas laws let us calculate different values for gases.

Boyle's Law

One of the ideal gas laws is Boyle's law. Boyle's law states that pressure and volume are inversely proportional. This means that as pressure increases, volume decreases and vice versa. In equation form, Boyle's law is:

This means to find the original pressure, all we have to do is plug in the known values and solve for P₁.

Solving for P

Firstly, let's plug in the known volumes and pressure.

Then, divide both sides by 2.7 to find the original pressure.

Since this equation is based on measured values, we should round to significant figures. Rounded to 2 sig figs, the original pressure was 13 atm.

The balanced chemical equation for the combustion of [tex]CH_{3}[/tex] (methane) is:

[tex]CH_{4} + 2O_{2} = > CO_{2} + 2H_{2} O[/tex]

From the balanced equation, we can see that for every mole of [tex]CH_{4}[/tex] combusted, one mole of [tex]CO_{2}[/tex] is formed.

Given that 25 moles of [tex]CH_{3}[/tex] (methane) combust, we can assume that it refers to 25 moles of [tex]CH_{4}[/tex] since they have the same chemical formula.

Therefore, the number of moles of [tex]CO_{2}[/tex] formed will also be 25 moles, as the reaction produces an equal number of moles of [tex]CO_{2}[/tex].

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Approximately 0.157 liters or 157 milliliters of the 4.50 M HCl solution can be made by mixing the given solutions.

To determine the volume of 4.50 M HCl that can be made by mixing the given solutions, we can use the concept of the concentration-volume relationship:

C1V1 = C2V2

Where:

C1 = concentration of the first solution

V1 = volume of the first solution

C2 = concentration of the second solution

V2 = volume of the second solution

Let's assign the variables as follows:

C1 = 5.65 M

V1 = unknown volume (we'll solve for this)

C2 = 3.55 M

V2 = 250.0 mL = 0.250 L (since the volume is given in milliliters)

Now we can plug in the values into the equation and solve for V1:

(5.65 M)(V1) = (3.55 M)(0.250 L)

Dividing both sides of the equation by 5.65 M:

V1 = (3.55 M)(0.250 L) / 5.65 M

V1 ≈ 0.157 L

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Answer:DNA, along with RNA and proteins, is one of the three major macromolecules that are essential for life. Most of the DNA is located in the nucleus, although a small amount can be found in mitochondria (mitochondrial DNA). Within the nucleus of eukaryotic cells, DNA is organized into structures called chromosomes.

Explanation: science

Q ≈ -2000 J

Temperature changes can be used to calculate heat transfer. Please note that since the question is based on measured values I rounded for significant figures.

Heat Transfer

In heat transfer, energy can be gained or lost. When energy is gained, temperature increases. However, when energy is lost, temperature decreases. Since the water decreased in temperature, it must have lost energy. This means that Q will be negative. Q represents the transfer of energy, which is measured in joules.

Calculating Energy

To calculate heat transfer we can use the equation q = m·c·ΔT.

For this question, we know that the mass is 75.0g. Specific heat is a constant that every substance has. These values can be found in data tables. For liquid water, c = 4.184. Finally, the change in temperature is -7°C.

In this scenario, 2196.6 joules of energy were lost. Since -7 has one sig fig, this answer can be rounded to 2000 J.

386°C

The ideal gas law allows us to solve for different values of a gas.

Ideal Gas Law

In order to do ideal gas calculations, we make the assumption that gas behaves ideally. This means that gases move in completely straight lines, have perfectly elastic collisions, experience no IMFs (intermolecular forces), and have no volume. When we assume these characteristics, we get the equation:

In this equation, P is pressure, V is volume, n is moles, R is the gas constant, and T is temperature. It is important to note that temperature is always given in Kelvin for the ideal gas law.

Solving For T

To solve for T, all we need to do is plug in the values we were given. The question states:

Now we just need to solve for T. For clarity, I will leave units out of this calculation.

This means the temperature is about 658.82 Kelvin. Rounded for sig figs, this is 659K. However, the question asks for Celsius. So, we need to convert. To convert from Kelvin to Celsius, subtract 273.

The gas is at 386°C.

An increase in temperature during the reaction is an indication that the reaction released chemical energy

The increase in temperature during a reaction in a closed system indicates that the reaction releases chemical energy.

This is because an increase in temperature indicates that energy is being released into the surroundings, and the only way that can happen in a closed system is if it is released by the reaction taking place within the system.

In other words, the correct answer is C. The reaction releases chemical energy.

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The alpha particles have the lowest penetrating power, followed by beta particles, while gamma rays possess the highest ability to penetrate substances.

In increasing order of their ability to penetrate substances, the different types of radioactive decay are:

Alpha particle: Alpha particles consist of two protons and two neutrons and are relatively large and heavy. Due to their size and positive charge, they have limited penetrating power and can be easily stopped by a sheet of paper or a few centimeters of air.

Beta particle: Beta particles are high-energy electrons (beta-minus decay) or positrons (beta-plus decay) emitted during radioactive decay. They have greater penetrating power than alpha particles but are still relatively easily stopped by a few millimeters of aluminum or a few meters of air.

Gamma ray: Gamma rays are electromagnetic waves with high energy and frequency. They have the highest penetrating power among the three types of radioactive decay. Gamma rays require thick layers of dense materials such as lead or concrete to significantly reduce their intensity.

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When the volume of the system is decreased, the pressure will increase, causing the reaction to shift in the direction that produces fewer gas molecules. In this case, the reaction shifts towards the formation of CO2, increasing the concentration of all species (CO, O2, and CO2).

After each event listed, the changes in concentration for each species to reach equilibrium can be determined:

Increasing the concentration of CO:

CO will decrease (↓)

O2 will not change (blank)

CO2 will increase (↑)

Increasing the concentration of CO2:

CO will not change (blank)

O2 will not change (blank)

CO2 will increase (↑)

Decreasing the volume of the system:

CO will increase (↑)

O2 will increase (↑)

CO2 will increase (↑)

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A unit of measurement called a mole is used to determine how much of a material there is. We must utilise Avogadro's number, which equals 6.022 x 1023 particles per mole, to convert moles to particles. The Avogadro constant is another name for this quantity.

We must multiply 80 moles of CH4 by Avogadro's number in order to transform it to particles. The computation looks like this: 80 moles x a particle density of 6.022 x 1023 per mole = 4.8176 x 1025 particles. 80 moles of CH4 are therefore equivalent to 4.8176 x 1025 particles.

Particles refer to the individual units, such as atoms or molecules, inside a material, whereas moles are the basic unit used to estimate the amount of a substance. Approximately 6.022 x 1023 particles per mole, or Avogadro's number, serves as a conversion factor between moles and particles.

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Answer:

As the temperature of water increases, the speed of sound waves traveling through it also increases. Therefore, if the water temperature increases from 0°C to 20°C, the speed of the sound wave traveling through it will increase.

The speed of a sound wave in water will increase if the water's temperature increases from 0°C to 20°C due to increased particle collisions resulting from higher kinetic energy.

The best statement that describes how the speed of a wave will change if the water temperature increases from 0°C to 20°C is - The wave speed will increase because the particles will collide more frequently.

This is because an increase in temperature of a fluid (like water) results in an increase in the speed of sound through it. When the temperature increases, the kinetic energy of the particles also increases. As a result, these molecules move around faster, thereby leading to increased collisions which essentially helps the sound wave to propagate faster. So, the speed of the sound wave increases with an increase in temperature.

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