What substituent(s) might you add to convert benzoic acid into a very strong acid? Draw its structure and explain your reasoning

Answer: H2O2

Explanation: The formula that represents hydrogen peroxide is H2O2

Answer: Look at the image I attached - I drew what you should write.

The percent yield of the reaction is 80%.

To calculate the percent yield, we need to use the following formula:

The actual yield of the reaction is 342 mg.

To calculate the theoretical yield, we need to first calculate the number of moles of (E)-stilbene and pyridinium bromide perbromide used in the reaction:

Number of moles of (E)-stilbene

Number of moles of pyridinium bromide perbromide

Theoretical yield of meso-stilbene dibromide = number of moles of (E)-stilbene x 2 = 0.002364 mol x 340.05 g/mol = 803 mg

Now we can substitute the values into the formula:

Therefore, the percent yield of the reaction is 80%.

To learn more about percent yield, here

https://brainly.com/question/17042787

#SPJ4

He can do this either by changing the temperature to 150 kelvins or by changing the pressure to 200 kilopascals.

The ideal gas law is a fundamental principle in thermodynamics and describes the behavior of ideal gases under various conditions. It is mathematically represented by the equation:

PV = nRT

where:

P is the pressure of the gas,

V is the volume of the gas,

n is the number of moles of the gas,

R is the ideal gas constant, and

T is the absolute temperature of the gas.

The ideal gas law relates the pressure, volume, temperature, and amount of gas (number of moles) in a system. It assumes that the gas molecules do not interact with each other and occupy negligible volume compared to the total volume of the container. The ideal gas law allows for the calculation of any one of the variables (pressure, volume, temperature, or number of moles) if the other three are known.

Based on the Ideal Gas Equation,

V ∝ T

V ∝ 1/P

Using T :

V₁/T₁ = V₂/T₂

200/300 = 100/T₂

T₂ = 100/200 x 300

T₂ = 0.5 x 300

T₂ = 150 K

Using P :

P₁V₁ = P₂V₂

100 x 200 = P₂ x 100

P₂ = 200 kPa

Learn more about Ideal gas Equation, here:

https://brainly.com/question/30935329

#SPJ12

Answer:

you equate the question 800×7.2 divide the answer by 735.And you'll get 7.84litre then covert to 0.0m³ if the question says so to get 0.00784

A heating curve is a graphical representation of how a substance's temperature changes as it absorbs heat energy.

The x-axis represents the amount of heat energy added, while the y-axis represents the temperature of the substance. The heating curve can be divided into three portions, each representing different changes in the substance's physical state and energy.

At the beginning of the heating curve, particles of the substance have the most kinetic energy when the substance is in its solid state. In this portion, the temperature remains constant as the added heat energy is used to break down the intermolecular forces holding the particles together.

This part of the curve is labeled the "melting point" or "fusion" section.

The next portion of the curve represents the transition from the solid to the liquid state. During this section, the temperature again remains constant as the added heat energy is used to overcome the intermolecular forces and convert the substance to a liquid state. This part of the curve is labeled the "boiling point" or "vaporization" section.

Finally, the last portion of the curve represents the liquid state. In this section, the temperature of the substance begins to increase as the added heat energy is used to increase the kinetic energy of the particles. This portion of the curve is labeled the "condensation" or "freezing" section, depending on whether the substance is being cooled or heated.

Overall, a heating curve is a useful tool for understanding how a substance's energy changes during heating, and how this affects its physical state.

To know more about heating curve, visit:

https://brainly.com/question/27018999#

#SPJ11

The total energy needed to convert the 475.0 grams of water at 40.0°C to steam at 100.0°C is 1,068,637.5 Joules.

The energy needed to change 475.0 grams of liquid water at 40.0°C to steam at 100.0°C is known as the latent heat of vaporization.

This amount of energy is required to overcome the forces that keep the molecules of water in a liquid state. In other words, it is the energy needed to break the bonds that keep the molecules of water in a liquid state.

To calculate the total energy needed, the latent heat of vaporization is multiplied by the mass of water. Therefore, the total energy needed to convert the 475.0 grams of water at 40.0°C to steam at 100.0°C is 1,068,637.5 Joules.

This energy needs to be supplied in the form of heat for the water to change from liquid to steam.

Know more about Latent heat of vaporization here

https://brainly.com/question/2598640#

#SPJ11

Answer:

320.3 grams of SO2 can be produced

Explanation:

In order to calculate the amount of SO2 produced, we first need to write a balanced chemical equation for the reaction between O2 and sulfur:

2 SO2 + O2 -> 2 SO3

From the equation, we can see that 1 molecule of O2 reacts with 2 molecules of SO2 to produce 2 molecules of SO3.

Therefore, we need to convert the number of O2 molecules to the number of SO2 molecules in order to calculate the amount of SO2 produced.

1 molecule of O2 reacts with 2 molecules of SO2, so:

2.5 molecules of O2 * (2 molecules of SO2 / 1 molecule of O2) = 5 molecules of SO2

Now that we have the number of SO2 molecules produced, we can calculate the mass of SO2 using its molar mass. The molar mass of SO2 is approximately 64.06 g/mol.

5 molecules of SO2 * (64.06 g/mol) = 320.3 grams of SO2

Therefore, if 2.5 molecules of O2 react with sulfur to form SO2, then 320.3 grams of SO2 can be produced.

Starting with 100 molecules of the first limiting reagent, the maximum number of product molecules that can be formed at the end of the final reaction, given the yields of each reaction, is 11 molecules.

Let's call the starting number of molecules of the first limiting reagent "A". Then, the number of molecules of each reactant and product after each reaction can be represented as follows,

Reaction 1: A → B (80% yield)

Starting molecules of A = 100

Molecules of B produced = 80

Reaction 2: B → C (90% yield)

Starting molecules of B = 80

Molecules of C produced = 72

Reaction 3: C → D (65% yield)

Starting molecules of C = 72

Molecules of D produced = 46.8 (rounded to 47)

Reaction 4: D → E (76% yield)

Starting molecules of D = 47

Molecules of E produced = 35.72 (rounded to 36)

Reaction 5: E → F (30% yield)

Starting molecules of E = 36

Molecules of F produced = 10.8 (rounded to 11)

Therefore, the maximum number of product molecules that can be formed at the end of the final reaction is 11, rounded to the nearest whole number.

To know more about reaction, here

brainly.com/question/30392167

#SPJ4

In the electrowinning process, the energy applied using 5 mol of IR photons with a wavelength of 32 nm is 1.863 MJ.

1. Convert wavelength to energy using the equation: E = (hc)/λ, where h is Planck's constant (6.626×10⁻³⁴ Js), c is the speed of light (3×10⁸ m/s), and λ is the wavelength (32 nm = 32×10⁻⁹ m).

2. Calculate the energy of one IR photon: E = (6.626×10⁻³⁴ Js × 3×10⁸ m/s) / (32×10⁻⁹ m) = 6.184×10⁻¹⁹ J.

3. Determine the energy for 5 moles of IR photons: Total energy = 6.184×10⁻¹⁹ J × 5 × 6.022×10²³ photons/mol = 1.863×10⁶ J.

4. Convert energy to megajoules: 1.863×10⁶ J = 1.863 MJ.

To know more about Planck's constant click on below link:

https://brainly.com/question/30763530#

#SPJ11

You need 0.25 grams of magnesium phosphate to make 250 mL of a 0.10% (m/v) solution.

To calculate the grams of solute required to make 250 mL of 0.10% magnesium phosphate (m/v), you'll first need to determine the mass of the solute in the solution.

1. Convert the percentage to a decimal: 0.10% = 0.0010.
2. Multiply the decimal by the volume of the solution: 0.0010 x 250 mL = 0.25 grams.
3. The result, 0.25 grams, is the mass of magnesium phosphate needed to make 250 mL of a 0.10% (m/v) solution.

In summary, to make a 250 mL solution with a 0.10% (m/v) concentration of magnesium phosphate, you will need to dissolve 0.25 grams of the solute in the solvent.

To know more about magnesium phosphate  click on below link:

https://brainly.com/question/3413068#

#SPJ11

Fossil fuels are the largest contributor of the  greenhouse  gas carbon dioxide,this causes health and environmental issues.

This causes health and environmental issues as it contributes to global warming and climate change. The burning of fossil fuels such as coal, oil and gas releases carbon dioxide into the atmosphere, which traps heat and leads to the Earth's temperature rising.

This can cause extreme weather events, rising sea levels, and harm to ecosystems and wildlife. Additionally, carbon dioxide can contribute to respiratory and cardiovascular health issues in humans and animals.

Therefore, it is important to transition to renewable energy sources in order to reduce our reliance on fossil fuels and mitigate the impacts of climate change.

To know more about global warming click on below link:

https://brainly.com/question/12908180#

#SPJ11

Answer:

[tex]H _{2} SO _{4}+NaOH→NaSO _{4} +H _{2} O[/tex]

hope it helps:)

Answer: Energy

Explanation:

Energy is the ability to do work or produce heat.

The correct answer is e. The concentrations of H2 and HI will decrease as the system is approaching equilibrium.

the equilibrium concentration of HI is 1.18 x 10^-4 M.

The correct answer is e. The concentrations of H2 and HI will decrease as the system is approaching equilibrium.

This is because the equilibrium constant, Kc, for the reaction is 64, which is a relatively large value. This suggests that the forward reaction (2HI → H2 + I2) is favored at equilibrium, meaning that the concentration of HI will decrease as the system approaches equilibrium.

To calculate the equilibrium concentration of HI, we can use the equilibrium constant expression:

Kc = [H2][I2]/[HI]^2

Substituting the given values, we get:

64 = (4.2 x 10^-4)(1.9 x 10^-3)/[HI]^2

Solving for [HI], we get:

[HI] = sqrt((4.2 x 10^-4)(1.9 x 10^-3)/64) = 1.18 x 10^-4 M

Therefore, the equilibrium concentration of HI is 1.18 x 10^-4 M.
Visit to know more about equilibrium:-

https://brainly.com/question/517289

#SPJ11

The energy required to heat 70.0 g of water from 18°C to boiling (100°C) is 24,518.56 J.

Using the heat exchange formula,

q = mcΔT, mass of water is m, specific heat is c and temperature change is ΔT. For water, the specific heat capacity is 4.184 J/g·°C. The temperature change is,

ΔT = (100°C - 18°C) = 82°C

Therefore, the amount of energy required to heat 70.0 g of water from 18°C to boiling is,

q = m × c × ΔT

q = (70.0 g) × (4.184 J/g·°C) × (82°C)

q = 24,518.56 J

Therefore, the energy required to heat the beaker of water is 24,518.56 J.

To know more about Heat change, visit,

https://brainly.com/question/28912732

#SPJ4

Enter your numerical answer with the correct number of significant figures: 5.24 moles.

Moles are small mammals that are known for their distinctive black or brown fur and their burrowing habits. They belong to the family Talpidae and are found in many parts of the world including North America, Europe, and some parts of Asia. Moles have small eyes and ears, short legs, and a long, cylindrical body. They typically measure around 3 to 5 inches in length and weigh around 1 to 4 ounces. They feed mostly on earthworms and other small invertebrates, and their diet is supplemented by insects, eggs, and other small animals. Moles have specialized claws and feet which allow them to dig quickly and efficiently.

To learn more about moles

https://brainly.com/question/15356425

#SPJ4

The electron-transfer method is a way to balance chemical reactions by assigning oxidation numbers to each element and then transferring electrons between the two sides of the equation until the number of electrons is equal on both sides.

In this case, the reactants are solid copper and dilute nitric acid, which will produce copper(II) nitrate, water, and nitrogen monoxide gas (NO).

The first step is to assign oxidation numbers to the elements. For copper, the oxidation number is 0, for nitrogen it is +3, for oxygen it is -2, and for hydrogen it is +1.

The next step is to transfer electrons between the two sides of the equation so that the number of electrons on each side is equal. In this case, we can transfer two electrons from the reactant side to the product side. This will result in the equation being balanced, with the copper being reduced to 0 and the nitrogen being oxidized to +5.

The balanced equation would look like this:

Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO

The electron-transfer method is a simple, effective way to balance chemical equations.

By assigning oxidation numbers and transferring electrons between the reactants and products, we can ensure that the equation is balanced and all atoms are conserved.

Know more about Nitric acid here

https://brainly.com/question/29769012#

#SPJ11

Robert Millikan later determined electron's charge in his "oil drop" experiments.

J.J. Thomson conducted experiments in the late 19th century where he used an electric field to deflect a beam of particles, known as a "cathode ray." These cathode rays were generated by applying a high voltage to a partially evacuated glass tube. Thomson observed that the beam was deflected towards the positive electrode, suggesting that the particles in the cathode ray had a negative charge. This led him to the discovery of the first subatomic particle, the electron.

Robert Millikan later conducted experiments to determine the charge of the electron. His famous "oil drop" experiments involved suspending tiny droplets of oil in an electric field and measuring the force required to keep them stationary. By measuring the charge on the oil droplets and the electric field strength, he was able to calculate the charge of the individual electrons that were present in the oil droplets. The discovery of the electron and its properties paved the way for future developments in particle physics and quantum mechanics. Today, we understand that atoms are made up of a nucleus composed of protons and neutrons, surrounded by electrons that orbit the nucleus in energy levels.

The conclusion is J. J. Thomson discovered the first subatomic particle, the electron, by deflecting a "cathode ray" beam with an electric field. Robert Millikan later determined that particle's charge in his "oil drop" experiments. The discovery of the electron was a crucial step in our understanding of the nature of matter and the structure of the universe.

To learn more about electron visit:

https://brainly.com/question/860094

#SPJ11

The total quantity of heat evolved when 10.0 g of steam at 200°C is condensed, cooled, and frozen to ice at 50°C is 410.56 kJ.

To calculate the total quantity of heat evolved, we need to break down the process into different steps:

Step 1: Condensation of 10.0 g of steam at 200°C

The heat evolved during condensation can be calculated using the formula:

q = m × ΔHvap

where q is the heat evolved, m is the mass of steam, and ΔHvap is the molar heat of vaporization of water, which is 40.7 kJ/mol.

First, we need to calculate the moles of steam:

n = m/M

where M is the molar mass of water, which is 18.02 g/mol.

n = 10.0 g / 18.02 g/mol = 0.555 mol

Now we can calculate the heat evolved during condensation:

q1 = n × ΔHvap = 0.555 mol × 40.7 kJ/mol = 22.5 kJ

Step 2: Cooling of liquid water from 100°C to 0°C

The heat evolved during cooling can be calculated using the formula:

q = m × c × ΔT

where q is the heat evolved, m is the mass of water, c is the specific heat capacity of water, and ΔT is the change in temperature.

We need to calculate the mass of water formed from the condensation of 10.0 g of steam. Since the density of water is 1 g/mL, we know that:

m_water = m_ice = V × ρ = 10.0 g/mL × 0.92 g/mL = 9.2 g

Now we can calculate the heat evolved during cooling:

q2 = 9.2 g × 4.18 J/g°C × (100 - 0)°C = 385 kJ

Step 3: Freezing of liquid water from 0°C to -50°C

The heat evolved during freezing can be calculated using the formula:

q = m × ΔHfus

where q is the heat evolved, m is the mass of water, and ΔHfus is the molar heat of fusion of water, which is 6.01 kJ/mol.

We need to calculate the moles of water:

n = m/M = 9.2 g / 18.02 g/mol = 0.510 mol

Now we can calculate the heat evolved during freezing:

q3 = n × ΔHfus = 0.510 mol × 6.01 kJ/mol = 3.06 kJ

Total heat evolved = q1 + q2 + q3 = 22.5 kJ + 385 kJ + 3.06 kJ = 410.56 kJ

To know more about heat evolved refer to-

https://brainly.com/question/31321782

#SPJ11

The pH of the resulting solution is 1.08 (rounded to two decimal places).

First, we need to calculate the amount of acid and base present:

moles of HCl = (0.10 mol/L) * (0.025 L) = 0.0025 mol \\moles of NaOH = (0.10 mol/L) * (0.005 L) = 0.0005 mol

Since HCl and NaOH react in a 1:1 ratio, all of the NaOH will be used up in the reaction and 0.0005 moles of HCl will be left unreacted.

So, total volume of the solution will be [tex]25.0 ml + 5.0 ml = 30.0 ml = 0.03 L[/tex]

The concentration of unreacted HCl will be:

C(HCl) = (0.0025 mol) / (0.03 L) = 0.0833 M

Now we can calculate the pH :  pH = -log[H+]

[H+] = 0.0833 M \\pH = -log(0.0833) = 1.08

To know more about solution, here

brainly.com/question/30665317

#SPJ4

Answer:

pH = 1.18

Explanation:

First, calculate the moles of acid in the solution:

(0.0250 L )(0.10molL)=0.0025 mol acid

Next, calculate the moles of base:

(0.0050 L)(0.10molL)=0.00050 mol base

The strong acid and strong base will dissociate completely to generate the same number of moles of hydronium and hydroxide, respectively. The amount of acid exceeds the amount of base, so all the added hydroxide will neutralize an equivalent amount of hydronium. To find the remaining amount of hydronium, we subtract the moles of hydroxide added (equal to the moles of hydronium neutralized) from the moles of hydronium added:

0.0025 mol H3O+−0.00050 mol OH−=0.0020 mol H3O+

To find the concentration of hydronium, we must divide this number of moles by the total volume of solution, being sure to add the volumes of acid and base added together:

0.0020 mol H3O+0.0300 L≈0.06667 M H3O+

Finally, take the negative logarithm of this amount to obtain the pH.

-log(0.06667)=1.18

Since the hydronium concentration is only precise to two significant figures, the logarithm should be rounded to two decimal places.

The type of reaction for the given equation is a double displacement reaction, where the sodium bicarbonate and citric acid react to form sodium citrate and carbonic acid. The carbonic acid then undergoes a decomposition reaction to produce water and carbon dioxide. This type of reaction is called a decomposition reaction.

The symbols inside the parentheses after the formula of the compounds represent the chemical structure of the molecule. In the case of citric acid, the parentheses indicate the presence of three carboxylic acid functional groups, which are responsible for its acidity.

The presence of these groups also allows for the reaction with sodium bicarbonate to occur, forming sodium citrate and carbonic acid. Overall, this reaction demonstrates the principles of acid-base chemistry and the importance of understanding chemical structures in predicting reactions.

To know more about given equation is a double displacement refer here

https://brainly.com/question/14057630#

#SPJ11

The correct answer is: The dianion can form a resonance-stabilized conjugated ring, which tends to absorb visible light.

The correct answer is: The dianion can form a resonance-stabilized conjugated ring, which tends to absorb visible light.

In the first part of the experiment, the reagents used are benzidine and hydrogen peroxide, which react to form a compound called a dianion. This dianion is initially colorless, but when sodium hydroxide is added, it causes the dianion to undergo a rearrangement that forms a resonance-stabilized conjugated ring. This conjugated ring absorbs visible light in the blue-green range, which causes the solution to appear red. This color change is used as an indicator for the presence of blood in forensic and medical labs because benzidine and its derivatives are known to react with the heme group found in blood to form a similar colored proproductduct.
Visit to know more about conjugated ring:-

https://brainly.com/question/15047805

#SPJ11

The a and c lattice parameters can be used to calculate the volume of a hcp unit cell i.e.  [tex]\( V = \frac{3}{2} \sqrt{3} a^2 c \)[/tex], and the atomic packing factor for the hcp crystal structure is 0.74, which represents the percentage of space occupied by atoms in the unit cell.

In a hexagonal close-packed (hcp) unit cell, there are six atoms located at the corners of a regular hexagon, and a seventh atom at the center of the hexagon. The unit cell has a height of c and a base with sides of length a. The volume of the unit cell can be calculated as:

[tex]\( V = \frac{3}{2} \sqrt{3} a^2 c \)[/tex]

To show that the atomic packing factor (APF) for an hcp crystal structure is 0.74, we need to calculate the total volume occupied by the atoms in the unit cell and divide it by the total volume of the unit cell.

The volume of one atom can be approximated as a sphere with a radius of a/2, so its volume is [tex]\( \frac{4}{3} \pi \left(\frac{a}{2}\right)^3 = \frac{4}{3} \pi \frac{a^3}{8} \)[/tex]. There are two types of atoms in an hcp unit cell: the six atoms at the corners of the hexagon and the central atom. So the total volume of atoms in the unit cell is:

[tex]\( V_{\text{atom}} = \frac{6}{8} \cdot \frac{4}{3} \pi a^3 + \frac{4}{3} \pi a^3 \)[/tex]

= [tex]\(\frac{2 \sqrt{3} \pi a^3}{3}\)[/tex]

The total volume of the unit cell is just [tex]\(a^2 \cdot c \cdot \sqrt{3} / 2\)[/tex]. So the APF is:

[tex]\( \text{APF} = \frac{V_{\text{atom}}}{V_{\text{cell}}} \)[/tex]

= [tex]\(\frac{2 \sqrt{3} \pi a^3}{3 (a^2 c \sqrt{3} / 2)}\)[/tex]

=[tex]\(\frac{2\pi a}{\sqrt{3}c}\)[/tex]

≈ 0.74

Therefore, the volume of an hcp unit cell can be expressed as [tex]\( \frac{3}{2} \sqrt{3} a^2 c \)[/tex], and the APF for an hcp crystal structure is approximately 0.74.

To know more about the hcp unit cell refer here :

https://brainly.com/question/15904338#

#SPJ11

When a 27. 7 g sample of ethylene glycol (C = 2. 42 J/gºC) at 42. 76°C is cooled to 32. 5°C the amount of heat released is  685.87 joule.

To calculate the heat released when a 27.7 g sample of ethylene glycol is cooled from 42.76°C to 32.5°C, you can use the formula:

q = mcΔT

where q represents the heat released, m is the mass (27.7 g), c is the specific heat capacity (2.42 J/gºC), and ΔT is the change in temperature (42.76°C - 32.5°C).

ΔT = 42.76°C - 32.5°C = 10.26°C

Now plug in the values into the formula:

q = (27.7 g) × (2.42 J/gºC) × (10.26°C) = 685.87 J

So, 685.87 Joules of heat are released when the 27.7 g sample of ethylene glycol is cooled from 42.76°C to 32.5°C.

Know more about Specific heat capacity here:

https://brainly.com/question/29766819

#SPJ11

The best classification for the creation of a complex ion like Cu(NH3)4 2+ (aq) is a Lewis acid-base reaction. The NH3 molecules serve as Lewis bases in this process, while the Cu2+ ion functions as a Lewis acid by accepting a pair of electrons from them. As a result, a coordination complex is created that contains four NH3 ligands and a Cu2+ ion.

Covalent coordinate bonds are created when the NH3 molecules give the Cu2+ ion a pair of electrons from their lone pairs. As a result, a stable complex ion with a net charge of 2+ is created, with the Cu2+ ion at its centre and four NH3 ligands surrounding it.

Overall, the formation of complex ions involves the interaction of a Lewis acid (metal ion) and a Lewis base (ligand), resulting in the formation of a coordinate covalent bond.

For more questions on:  molecules

https://brainly.com/question/22312099

#SPJ11  

The formation of a complex ion such as Cu(NH3)4 2+ (aq) can be best categorized as a coordination complex.

For such more question on complex ion

https://brainly.com/question/24262383

#SPJ11

The characteristic that would be preferred for a better resonance structure is maximized bond strength. Option B is correct.

Maximizing bond strength is a crucial characteristic for a better resonance structure because it leads to a more stable structure. Resonance structures are a set of contributing structures that show the delocalization of electrons in a molecule. These structures should have similar energies and contribute equally to the actual structure of the molecule. The more stable a resonance structure, the greater its contribution to the actual structure.

Formal charges are important for resonance structures, but a minimal formal charge or negative formal charges on the most electronegative atom are not the only factors that contribute to a better resonance structure. In fact, some resonance structures may have formal charges that are not minimized or negative formal charges on less electronegative atoms.

Maximizing bond strength ensures that the structure is stable and contributes significantly to the actual structure of the molecule. Therefore, maximizing bond strength is the most important characteristic for a better resonance structure. Option B is correct.

To know more about the Resonance structure, here

https://brainly.com/question/29375608

#SPJ4

The molecularity of a reaction refers to the number of molecules or particles that are involved in the rate-determining step of the reaction.

In an elementary reaction, the reaction occurs in a single step, and its molecularity is determined by the number of reactant molecules that are involved in this step.

In the case of [tex]Cl2[/tex] falling apart, the reaction can be represented as:

[tex]Cl2 → 2Cl[/tex]

Since this reaction involves only one[tex]Cl2[/tex] molecule in the rate-determining step, the molecularity of the reaction is unimolecular, or simply "1". This means that the reaction rate is dependent only on the concentration of [tex]Cl2[/tex], and no other species are involved in the rate-determining step.

To know more about molecularity refer to-

https://brainly.com/question/31567167

#SPJ11

The calculation of the mass of SnF₂ present in the toothpaste sample determined it to be 0.105 g. The mass percentage of stannous fluoride in the toothpaste sample was found to be 1.05%. The percent yield of the extraction/recovery process, comparing the recovered mass of SnF₂ to the expected mass based on the percentage listed on the box, was calculated to be 70.0%. This indicates a moderate level of efficiency in the extraction/recovery process.

To solve this problem, we need to use stoichiometry and the concept of percent yield.

1. Calculation of the mass of SnF₂ present in the toothpaste sample:

Let's assume that all the SnF₂ in the toothpaste sample was extracted and precipitated.

The balanced chemical equation for the reaction between stannous fluoride and lanthanum nitrate is:

SnF₂ + 2La(NO₃)3 → La₂(SnF₆) + 6NO₃

According to the equation, 1 mole of SnF₂ reacts with 2 moles of La(NO₃)₃ to form 1 mole of La2(SnF6).

The molar mass of SnF2 is 156.69 g/mol.

Therefore, the number of moles of SnF₂ in the toothpaste sample is:

n(SnF₂) = (0.105 g)/(156.69 g/mol) = 0.0006701 mol

Since the stoichiometric ratio of SnF₂ to La₂(SnF₆) is 1:1, the number of moles of La₂(SnF₆) formed is also 0.0006701 mol.

The mass of SnF2 present in the toothpaste sample is:

m(SnF₂) = n(SnF₂) × M(SnF₂) = 0.0006701 mol × 156.69 g/mol = 0.105 g

Therefore, the mass of SnF₂ present in the toothpaste sample is 0.105 g.

2. Calculation of the mass percentage of stannous fluoride in the toothpaste sample:

The mass percentage of SnF₂ in the toothpaste sample is:

% mass = (mass of SnF₂ / mass of toothpaste sample) × 100%

The mass of the toothpaste sample is given as 10.00 g.

Therefore, the mass percentage of SnF₂ in the toothpaste sample is:

% mass = (0.105 g / 10.00 g) × 100% = 1.05%

Therefore, the mass percentage of stannous fluoride in the toothpaste sample is 1.05%.

3. Analysis of the percent yield of the extraction/recovery process:

The percentage of SnF₂ listed on the box was 1.50%.

The percent yield of the extraction/recovery process is calculated as:

% yield = (mass of SnF₂ recovered / expected mass of SnF₂) × 100%

The expected mass of SnF₂ in the toothpaste sample, based on the percentage listed on the box, is:

mass of SnF₂ expected = (1.50% / 100%) × 10.00 g = 0.150 g

Therefore, the percent yield of the extraction/recovery process is:

% yield = (0.105 g / 0.150 g) × 100% = 70.0%

This means that the efficiency of the extraction/recovery process was 70.0%, which is not very high. It could be due to various factors such as incomplete extraction or loss of SnF₂ during the precipitation process.

To know more about the stannous fluoride refer here :

https://brainly.com/question/29227059#

#SPJ11

The expression that describes the heat evolved in a chemical reaction when carried out at constant pressure is ΔH = ΔE - w. Here, ΔH represents the enthalpy change, ΔE represents the internal energy change (also symbolized as ΔU), and w represents the work done.

Enthalpy is the sum of the internal energy of a system and the product of its pressure and volume. At constant pressure, the change in enthalpy is equal to the heat evolved or absorbed in the reaction. This is because any work done during the reaction is accounted for in the change in volume term of enthalpy, and at constant pressure, this term is constant. Therefore, the heat evolved or absorbed in the reaction is solely responsible for the change in enthalpy.

When a chemical reaction is carried out at constant pressure, the heat evolved in the reaction can be described using the symbol q, which represents heat. This is because, at constant pressure, the change in internal energy (symbolized by ΔE or ΔU) is equal to the heat absorbed or released in the reaction (represented by q) minus any work done (represented by w). Therefore, to explain the heat evolved in a chemical reaction at constant pressure, we would use the symbol q.

Learn more about internal energy at https://brainly.com/question/25737117

#SPJ11