Calculate the mass of phosphoric(V) acid, H3PO4 , formed in the reaction

The amount, in kJ, of heat needed to completely vaporize 50.0g of water at 100°C is 118.8 kJ.

The heat needed to completely vaporize 50.0g of water at 100°C can be calculated using the following formula:

q = m x Hv

where:

First, we need to convert 50.0g to moles by dividing by the molar mass of water which is approximately 18.015 g/mol3:

moles of water = 50.0 g / 18.015 g/mol moles of water = 2.776 mol

Thus:

q = (2.776 mol) x (40.65 kJ/mol) q = 112.8 kJ

In other words, 112.8 kJ of heat is needed to completely vaporize 50.0g of water at 100°C.

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Practical science work is advantageous because it fosters a better understanding of theoretical science.

The advantages of practical work in science include a better understanding of theoretical concepts, hands-on experience, development of laboratory skills, and increased interest in the subject.

Additionally, practical work can promote critical thinking and problem-solving skills.

However, practical work can also be time-consuming and costly, with the need for specialized equipment and safety precautions. Furthermore, results may be subject to human error, and not all experiments are repeatable.

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We can not use a salt bridge saturated with potassium chloride solution in an electro-chemical cell made from a Ag/Ag+ cathode and a Cu/Cu²+ anode because it will precipitate.

An electrochemical cell that uses a weak electrolyte and a salt bridge to connect oxidation as well as reduction half cells. A junction that joins the anodic with cathodic compartments of a cell and electrolytic solution is referred to as a salt bridge.

Because both chloride and potassium ions have very similar diffusion coefficients and minimise junction potential, the inactive minerals potassium chloride (KCl) frequently used. We can not use a salt bridge saturated with potassium chloride solution in an electro-chemical cell made from a Ag/Ag+ cathode and a Cu/Cu²+ anode because it will precipitate.

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The mass (in grams) of NaCl present in 87.5 moles of NaCl is 5118.75 grams

From the question given above, the following data were obtained:

Mole is related to mass and molar mass as follow:

Mole = Mass / Molar mass

Inputting the given parameters, we can obtain the mass of NaCl as follow:

87.5 = Mass of NaCl / 58.5

Cross multiply

Mass of NaCl = 87.5 × 58.5

Mass of NaCl = 5118.75 grams

Therefore, the mass of NaCl present is 5118.75 grams

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The balanced equation for the reaction between benzene and chlorine gas is: C6H6 + Cl2 → C6H5Cl + HCl

In this reaction, benzene reacts with chlorine gas to produce chlorobenzene and hydrogen chloride as a byproduct.

This reaction is an example of electrophilic aromatic substitution, where the chlorine molecule acts as an electrophile, or electron-poor species, and the benzene ring acts as a nucleophile, or electron-rich species.

The chlorine molecule is first activated by a catalyst, such as iron or aluminum chloride, to become an electrophile that can react with the benzene ring.

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Chlorobenzene, C6H5Cl, is used in the production of chemicals such as aspirin and dyes. One way that chlorobenzene is prepared is by reacting benzene, C6H6, with chlorine gas according to the following BALANCED equation. C6H6 (l) + Cl2 (g) → C6H5Cl (s) + HCl (g).

a. To calculate the theoretical yield of chlorobenzene, we need to use stoichiometry to determine how many moles of chlorobenzene can be produced from 45.6 g of benzene.

The molar mass of benzene (C6H6) is 78.11 g/mol.

We start by calculating the number of moles of benzene

45.6 g C6H6 x (1 mol C6H6/78.11 g C6H6) = 0.583 mol C6H6

From the balanced equation, we see that 1 mole of benzene reacts with 1 mole of chlorine gas to produce 1 mole of chlorobenzene. Therefore, the number of moles of chlorobenzene produced will be the same as the number of moles of benzene

0.583 mol C6H6 x (1 mol C6H5Cl/1 mol C6H6) = 0.583 mol C6H5Cl

Now, we can calculate the theoretical yield of chlorobenzene

Theoretical yield = number of moles of C6H5Cl x molar mass of C6H5Cl

The molar mass of chlorobenzene (C6H5Cl) is 112.56 g/mol.

Theoretical yield = 0.583 mol C6H5Cl x 112.56 g/mol = 65.6 g C6H5Cl

Therefore, the theoretical yield of chlorobenzene is 65.6 g.

b. The percent yield can be calculated using the formula

Percent yield = (actual yield / theoretical yield) x 100%

Putting in the given values

Percent yield = (63.7 g / 65.6 g) x 100% = 97.1%

Therefore, the percent yield of chlorobenzene is 97.1%.

The given question is incomplete and the complete question is '' Chlorobenzene, C6H5Cl, is used in the production of chemicals such as aspirin and dyes. One way that chlorobenzene is prepared is by reacting benzene, C6H6, with chlorine gas according to the following BALANCED equation. C6H6 (l) + Cl2 (g) → C6H5Cl (s) + HCl (g).

a. What is the theoretical yield if 45.6 g of benzene react?

b. If the actual yield is 63.7 g of chlorobenzene, calculate the percent yield''.

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Answer:

The balanced chemical equation for the decomposition of solid lithium chloride into chlorine gas and solid lithium can be written as:

2LiCl(s) → 2Li(s) + Cl2(g)

This equation shows that for every 2 moles of solid lithium chloride, 2 moles of solid lithium and 1 mole of chlorine gas are produced. The equation is balanced because the number of atoms of each element is the same on both sides of the equation. There are 2 lithium atoms, 2 chlorine atoms, and 0 oxygen atoms on both the reactant and product side of the equation.

The correct option is C. Friction is the force that keeps your tires from sliding around on the road.

Friction is the force exerted by a surface when an object moves across it. It always acts in the opposite direction of the movement of the object. That is it resists the movement of the object and if there's no force acting on the moving object, the frictional force will eventually stop the motion of the object.

In absence of friction the tires of the vehicles and even humans would not have been able to cover a distance without slipping and falling.

Therefore, the correct option is C. Friction is the force that keeps your tires from sliding around on the road.

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The charge on the ions in an ionic compound containing cobalt(III) and fluoride ions is Co³⁺ and F⁻¹ and the formula of the compound is CoF₃.

Ionic compounds are a type of chemical compound where the oppositely-charged ions of a metal and a nonmetal are attracted to each other to form an ionic bond.

The compound formed from the bonded ions will have very different properties from the elements that make up the compound.

While atoms are neutral because they have an equal number of protons and electrons, ions have a net charge and result when an atom loses or gains electrons.

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Answer:

i going off the top of my head

Explanation

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Answer:

[tex]16.68g ZnCl_2[/tex]

[tex]0.2472g H_2[/tex]

Explanation:

1.)Write equation:

[tex]Zn(aq)+HCl(aq)== > ZnCl_2(aq)+H_2(g)[/tex]

2.)Balance:

[tex]Zn(aq)+2HCl(aq)== > ZnCl_2(aq)+H_2(g)[/tex]

3.)Convert:

[tex]8g Zn/\frac{1mol Zn}{65.380g Zn}/\frac{1mol ZnCl_2}{1mol Zn}/\frac{136.28g ZnCl_2}{1mol ZnCl_2} =16.68g ZnCl_2[/tex]

[tex]8g Zn/\frac{1mol Zn}{65.380g Zn}/\frac{1 molH_2}{1molZn}/\frac{2.02g H_2}{1mol H_2}=0.2472g H_2[/tex]

(This does not include sig figs)

The percentage of yield of K₂PO₄ obtained from the reaction of 49.0 g of H₃PO₄ is 46.2%

We'll begin by obtaining the theoretical yield of K₂PO₄. Details below:

H₃PO₄ + 3KOH -> K₃PO₄ + 3H₂O

From the balanced equation above,

98 g of H₃PO₄ reacted to produce 212 g of K₃PO₄

Therefore,

49 g of H₃PO₄ will react to produce = (49 × 212) / 98 = 106 g of K₃PO₄

Thus, the theoretical yield of K₃PO₄ obtained is 106 g

Now, we shall determine the percentage yield of K₃PO₄. Details below:

Percentage yield = (Actual /Theoretical) × 100

Percentage yield of K₃PO₄ = (49 / 106) × 100

Percentage yield of K₃PO₄ = 46.2%

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Carbon atoms may thus form bonds to as many as four other atoms. For example, in methane (CH 4​start subscript, 4, end subscript), carbon forms covalent bonds with four hydrogen atoms

__________________________________________________________

The  name of the organic compound with structural formula of nine carbons and sixteen hydrogens  depends on different factors

The nomenclature of the organic molecule comprising nine carbons and sixteen hydrogens is determined by the arrangement of its atoms as well as the nature of the chemical bonds linking them together. Cyclononane is a circular formation of nine carbon atoms.

An organic substance belongs to a group of chemicals that have carbon atoms linked to each other and other atoms through covalent bonds, and are present in the biological cells. Organic compounds contain usual elements such as carbon, as well as hydrogen, oxygen, and nitrogen.

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The molecular mass of the gas, given that 2.63 g of the gas occupied 0.98 L at standard conditions of temperature and pressure is 60 g/mol

First, we shall obtain the mole of the gas. Details below:

PV = nRT

1 × 0.98 = n × 0.0821 × 273

0.98 = n × 22.4133

Divide both sides by 22.4133

n = 0.98 / 22.4133

n = 0.0437 mole

Finally, we shall obtain the molecular mass of the gas. This is shown below:

Molar mass = mass / mole

Molar mass of gas = 2.63 / 0.0437  

Molar mass of gas = 60 g/mol

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Answer: 5,266

Explanation:

5,266

Answer:

0.268

Explanation:

If you want to know how much of a radioactive substance is left after some time, you need to use some fancy math and some weird symbols. First, you need to know the decay constant (λ), which tells you how fast the stuff is disappearing. Then, you need to know the half-life (T1/2), which tells you how long it takes for half of the stuff to go poof. The formula to find out how much stuff is left is:

N = N0 ⋅ e − λt

where:

N = the amount of stuff left after time t N0 = the amount of stuff you started with λ = the decay constant t = the time that passed e = some number that nobody knows (just kidding, it's about 2.718)

For example, let's say you have some krypton-85, which is a radioactive gas that glows green. You have 100 grams of it and you want to know how much is left after 25 years. The half-life of krypton-85 is 10.76 years, so you can find the decay constant using this formula:

λ = ln 2 / T1/2

where:

ln 2 = natural log of 2 (about 0.693) T1/2 = half-life

So, you plug in the numbers and get:

λ = ln 2 / 10.76 λ ≈ 0.0644 year−1

Now you can use this value to find out how much krypton-85 is left using the first formula:

N/N0 = e − λt N/N0 = e − (0.0644)(25) N/N0 ≈ 0.268

This means that after 25 years, you have about 26.8% of krypton-85 left, or about 26.8 grams. The rest has turned into something else, probably something boring like argon or oxygen. The answer is 0.268.

The exit gas stream has an average molecular weight of 29.0 g/mol and the amount of leftover Phenanthrene in the reactor is 5377 g.

Start by calculating the stoichiometric amount of air required to burn 10 kg of Phenanthrene. The balanced chemical equation for the combustion of Phenanthrene is:

C₁₄H₁₀ + 19O₂ → 14CO2 + 5H₂O

Therefore, to burn 10 kg (10000 g) of Phenanthrene:

nO₂ = 19 x (10000 g / 178.24 g/mol) = 1065.5 mol

So the actual amount of oxygen supplied will be:

nO₂, supplied = 0.7 x nO₂ = 745.9 mol

The amount of air required to supply this much oxygen can be calculated using the ideal gas law:

PV = nRT

where P = pressure, V = volume, n = number of moles, R = gas constant, and T = temperature.

Assuming standard temperature and pressure (STP):

P = 1 atm = 101.3 kPa

T = 273 K

R = 8.314 J/mol.K

The volume of air required is then:

Vair = nair × RT/P = (nO₂,supplied + nN₂,supplied) × RT/P

where nN₂,supplied = number of moles of nitrogen in the supplied air.

Since air is about 79% nitrogen by volume, assume that the number of moles of nitrogen is proportional to the number of moles of oxygen:

nN₂,supplied = (0.79/0.21) x nO₂,supplied = 2807.2 mol

Therefore,

Vair = (nO₂,supplied + nN₂,supplied) × RT/P

= (745.9 + 2807.2) × 8.314 × 273 / 101.3

= 63106 L

Calculate the average molecular weight of the exit gas stream using the ideal gas law again:

n = PV/RT

where n = number of moles of gas, P = pressure, V = volume, R = gas constant, and T = temperature.

Assuming that the combustion products are at the same temperature and pressure as the supplied air (STP):

nCO₂ = nH₂O = nO₂,supplied = 745.9 mol

nN₂ = nN₂,supplied = 2807.2 mol

The total number of moles of gas in the exit stream is then:

ntotal = nCO₂ + nH₂O + nN₂ = 745.9 + 745.9 + 2807.2 = 4298.0 mol

The volume of the exit stream can be calculated using the ideal gas law:

Vexit = ntotal × RT/P = 4298.0 × 8.314 × 273 / 101.3 = 36534 L

The average molecular weight of the exit gas stream is then:

M = mtotal/ntotal

where mtotal = total mass of gas in the exit stream.

Calculate mtotal by adding up the mass of each component in the exit stream:

mtotal = mCO₂ + mH₂O + mN₂

where mCO₂, mH₂O, and mN₂ = masses of carbon dioxide, water vapor, and nitrogen, respectively.

Calculate these masses using the molecular weights of the compounds and the number of moles:

mCO₂ = nCO₂ × MCO₂ = 745.9 × 44.01 g/mol = 32804 g

mH₂O = nH₂O × MH₂O = 745.9 × 18.02 g/mol = 13419 g

mN₂ = nN₂ × MN₂ = 2807.2 × 28.01 g/mol = 78617 g

Therefore,

mtotal = mCO₂ + mH₂O + mN₂ = 32804 + 13419 + 78617 = 124840 g

Substituting into the equation:

M = mtotal/ntotal = 124840 g/4298.0 mol = 29.0 g/mol

So the exit gas stream has an average molecular weight of 29.0 g/mol.

The leftover Phenanthrene amount can be calculated as follows:

mPhenanthrene,leftover = mPhenanthrene,initial - mCO₂ - mH₂O

where mPhenanthrene,initial = initial mass of Phenanthrene, which is 10 kg (10000 g).

Substitute these values into the equation:

mPhenanthrene,leftover = 10000 - 32804 - 13419 = 5377 g

Therefore, the amount of leftover Phenanthrene in the reactor is 5377 g.

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The correct measure of density is g/cm³ (option A)

Density is a measure of the mass of matter contained by a unit volume. The symbol most often used for density is ρ, although the Latin letter "D" can also be used.

Density is the measurement of how tightly a material is packed together. It is defined as the mass per unit volume.

The formula for density is d = M/V

where;

Density is commonly expressed in units of grams per cubic centimetre (g/cm³).

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The molecular formula is twice the empirical formula which is (NH₂)₂ or N₂H₄.

To determine the molecular formula of the compound, find the empirical formula first. The empirical formula gives the simplest whole number ratio of atoms present in a compound.

Assuming we have 100 g of the compound, then 87.4 g of it is nitrogen and 12.6 g of it is hydrogen:

moles of N = 87.4 g / 14.01 g/mol = 6.24 mol

moles of H = 12.6 g / 1.01 g/mol = 12.5 mol

Find the simplest whole number ratio of moles of nitrogen to moles of hydrogen. To do this, we divide both values by the smaller one (in this case, 6.24 mol):

moles of N / 6.24 = 6.24 mol / 6.24 mol = 1

moles of H / 6.24 = 12.5 mol / 6.24 mol = 2

So the empirical formula is NH₂.

To find the molecular formula, know the molecular mass of the compound

The molecular mass of the compound is given as 32.05 g/mol. The empirical formula mass of NH₂ is:

empirical formula mass = 14.01 g/mol + 2(1.01 g/mol) = 16.03 g/mol

The molecular formula mass is a multiple of the empirical formula mass, divide the molecular mass by the empirical formula mass to find the multiple:

molecular mass / empirical formula mass = 32.05 g/mol / 16.03 g/mol = 2

Therefore, the molecular formula is twice the empirical formula:

(NH₂)₂ or N₂H₄.

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The ideal gas law may be used to determine the volume of oxygen created in the electrolysis that produces 548 litres of hydrogen at STP (Standard Temperature and Pressure). PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature, according to the ideal gas equation.

The pressure is 1 atm, the temperature is 273 K, and the number of moles of hydrogen is 548/22.4 = 24.5 in this example. We may compute the volume of oxygen created by rearranging the ideal gas law: V = nRT/P = 24.5*0.082*273/1 = 483.3 litres.

As a result, the volume of oxygen created in the electrolysis at STP that produces 548 litres of hydrogen is 483.3 litres.

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Answer:

56.96 grams

Explanation:

To find the mass of 1.78 moles of O2, we need to use the molar mass of O2, which is the mass of one mole of O2.

The chemical formula for O2 is O-O or simply O2. The molar mass of O2 is the sum of the atomic masses of two oxygen atoms, which can be found on the periodic table.

The atomic mass of oxygen (O) is approximately 16.00 g/mol. So the molar mass of O2 is:

Molar mass of O2 = 2 x atomic mass of O

= 2 x 16.00 g/mol

= 32.00 g/mol

Therefore, the mass of 1.78 moles of O2 is:

Mass = number of moles × molar mass

= 1.78 mol × 32.00 g/mol

= 56.96 g

So the mass of 1.78 moles of O2 is 56.96 grams.

1. Examples of solids, liquids, and gases found in a home

Solids: books, furniture, toys

Liquids: water, juice, shampoo

Gases: air, natural gas, propane

2. The human body contains solids, liquids, and gases. Solids include bones, muscles, and organs. Liquids include blood, saliva, and urine. Gases include air in the lungs and dissolved gases in the bloodstream. The body is mostly made up of liquids, as they make up a large percentage of its overall volume.

3. If you needed to remove the water from a sample of blood to study the solids that remained, you could use a process such as evaporation or freeze-drying. Evaporation involves heating the sample to allow the water to evaporate, leaving behind the solids. Freeze-drying involves freezing the sample and then removing the water under vacuum, leaving behind a dry solid.

4. Some metals that could be found within the human body include iron, zinc, and copper. These metals are commonly found in foods such as meat, seafood, nuts, and whole grains. Other metals such as calcium, magnesium, and potassium are also important for the body and are found in a variety of foods.

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Sound waves are mechanical waves that travel through a medium such as air, water, or solids. They are characterized by their frequency, wavelength, and amplitude. The correct answer is 4.

Frequency refers to the number of cycles of the wave that occur per unit of time and is measured in hertz (Hz). Wavelength is the distance between two adjacent points of a wave with the same phase. Amplitude is the maximum displacement of the particles in the medium from their rest position as the wave passes through it. Density, on the other hand, is a property of matter and not a characteristic of a sound wave. It refers to the mass per unit volume of a substance. Correct answer: 4.

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--The complete Question is, Which of these is not a property of a sound wave:

1. frequency,

2. wavelength,

3. amplitude,

4. density --

Answer:

The process by which nitrogen is obtained from air on a large scale is called the cryogenic distillation of air. This process involves cooling the air to very low temperatures (-183°C) to liquefy it. The air is then fed into a distillation column, which separates it into its components, including nitrogen and oxygen. Since nitrogen has a slightly lower boiling point than oxygen, it can be separated from oxygen by taking advantage of this difference in boiling points.

In the distillation column, the air is separated into its components by fractionation. The cold liquid air is fed into the column, where it is heated and allowed to boil. The nitrogen and oxygen gases that are formed are then separated and collected at different points along the column. The collected gases are then further purified to remove any remaining impurities before being compressed and stored for use.

This process is highly efficient and cost-effective, making it the most common method for obtaining nitrogen on a large scale. Nitrogen obtained through this process is used in a wide range of industrial applications, including chemical manufacturing, food packaging, and electronics production.

Answer:

D.) State the question, form a hypothesis, conduct an experiment

Explanation:

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The expression of the Ksp is Ksp =  [Ca²+] [2OH-]^2

In the balanced chemical equation for the solute's dissolution, Ksp is defined as the product of the ion concentrations in a saturated solution, each concentration being raised to the power of its stoichiometric coefficient.

Ksp is temperature-dependent and varies with different compounds. It is used to predict the maximum amount of a compound that can dissolve in a given solvent under specific conditions.

We know that we can be able to use the expression that has been given in the problem to arrive at the fact that;

Ksp =  [Ca²+] [2OH-]^2

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The concentration of NaCl (salt) when 4.9 moles are dissolved in 7 liters of water is 34.3M

Molarity is a unit of concentration measuring the number of moles of a solute per litre of solution.

Chemists primarily need the concentration of solutions to be expressed in a way that accounts for the number of particles that react according to a particular chemical equation. Since percentage measurements are based on either mass or volume, they are generally not useful for chemical reactions. A concentration unit based on moles is preferable.

Given,

Moles of NaCl = 4.9 moles

Volume = 7 L

Concentration = moles × volume (L)

= 34.3 M

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Answer:

Independent Variable: Number of Coils Wrapped Around

Dependent Variable: Number of Paperclips Magnet Picks Up

Possible Research Question: How does the number of wire wraps affect the strength of an electromagnet?

Trends noticed in the data: As the number of wire wraps (coils) around the nail increases, the magnetic strength of the electromagnet also increases. There is a positive correlation between the number of wire wraps and the number of paper clips the magnet picks up.

Claim based on the data: The magnetic strength of an electromagnet increases as the number of wire wraps (coils) around the nail increases.

Evidence from the chart or graph supporting the claim: The graph shows that as the number of wire wraps increases from 4 to 12, the number of paper clips the magnet picks up also increases from 6 to 25. This suggests a positive correlation between the two variables.

Adding a catalyst will not cause the equilibrium of the reaction to shift towards the products.

A catalyst is a substance that speeds up the rate of a chemical reaction without being consumed in the reaction. It does not affect the position of the equilibrium or the relative amounts of reactants and products at equilibrium.

In the given reaction, Si(s) + 2Cl₂(g) + heat ↔ SiCl₄(g), the forward reaction is exothermic, which means it releases heat. According to Le Chatelier's principle, an increase in temperature will shift the equilibrium towards the reactants side in order to counteract the increase in heat. Therefore, increasing the temperature will shift the equilibrium towards the left, reducing the yield of silicon tetrachloride.

Increasing the pressure of the system will also shift the equilibrium towards the side with fewer gas molecules, which is the products side. In this case, increasing the pressure will shift the equilibrium towards the products, increasing the yield of silicon tetrachloride.

Increasing the mass of both reactants and products by 20% will not affect the position of the equilibrium either, as it does not change the ratio of the concentrations of the reactants and products.

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