Before using a solution of n a o h as titrant in a titration experiment, you should standardize the solution. Standardization is the process of titrating a solution prepared from.

The Ka value of a protonated base is the acid ionization constant. Which can be calculated from the concentration of H+ ion and the conjugate base. The ka value of protonated urea of the given pH is 7.92 ×10⁻¹⁵.

pH of a solution is the measure of its H+ ion concentration. It is says how much acidic or basic the solution is. If the pH value is 7, then the solution is neutral and if it is less than 7 the solution is acidic. pH value greater than 7 indicates that the solution is basic.

pH of a solution mathematically is the negative logarithm of H+ ion concentration. Given that the pH of urea solution is 7.050. Thus its H+ ion concentration is calculated as follows;

-7.050 = log [H+]

[H+] = antilog (-7.050)

       = 8.9 × 10⁻⁸

Now when the protonated urea say it as HA is dissociated into its ions H+ and A-, then the ka value is written as;

[tex]Ka = \frac{[H+][A-]}{[HA]}[/tex]

Here, the [H+] and A- ion concentrations are equal and concentration of the solution HA is given 1 M.

Thus, Ka value of protonated urea can be calculated as follows:

Ka =  (8.9 × 10⁻⁸)² / (1-[ 8.9 × 10⁻⁸])

    = 7.92 ×10⁻¹⁵

Therefore, the acid ionization constant Ka of 1 M protonated urea with a pH of 7.050 is 7.92 ×10⁻¹⁵.

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Answer:

D. 32.

Explanation:

Remember the formula of atomic mass:

If you go to see the periodic table, you can note that the atomic mass of cobalt is 58.9 amu rounded to 59 amu. Let's solve for '# neutrons' and replace the atomic mass (59) and the atomic number (27) (remember that the number of protons is the same that the atomic number), like this:

The answer would be that the number of neutrons to make a cobalt atom most stable is D. 32.

The incorrect statement is, "reaction rate is the speed at which the reaction proceeds towards equilibrium".

The rate of the reaction is defined as the rate at which the reaction is taking place.

It is true that the rate of reaction is governed by the energy barrier between the reactant and the products.

Enzymes are special compounds which can accelerate the rate of reaction.

The rate of reaction is independent of the rate of temperature of the system. The rate of reaction depends on the concentration of the reactants.

Rate of the reaction is directly proportional to the increase in concentration of products.

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All are correct about two solutions of KCl and [tex] MgCl_{2}[/tex].

Both the compounds KCl and [tex] MgCl_{2}[/tex] are ionic compounds. So, they easily dissociate on contact water with constituent ions. KCl dissociates into one cation [tex] {K}^{+} [/tex] and one anion [tex] {Cl}^{-} [/tex]. [tex] MgCl_{2}[/tex] dissociates into one cation [tex] {Mg}^{2+} [/tex] and two anions [tex] {Cl}^{-} [/tex].

So, the KCl solution produces two ions while the [tex] MgCl_{2}[/tex] solution produces three ions. More number of ions means higher amount of charge can be carried at a time and hence higher conductivity will be seen. Likewise, less number of ions in the solution indicates less capacity to conduct electricity. Thus, [tex] MgCl_{2}[/tex] has higher amount of ions thus higher conductivity. Similarly, KCl has lesser amount of ions in the solution thus it has lower conductivity.

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Answer:

this is Daltons atomic theory

Answer:

this means that energy cannot be created or destroyed

Explanation:

it is because energy can change into many different forms such as heat or nuclear during chemical reactions

Based on the dissociation of each of the given salts, we can calculate that there are b. 51.5 g of chloride ions per liter of the solution.

Each mol of calcium chloride (CaCl₂) dissociates to give 2 moles of chloride ions. The number of moles of chloride ions that comes from calcium chloride is:

2 * 0.200 mol = 0.400 mol

Each mol of magnesium chloride (MgCl₂) dissociates to give 2 moles of chloride ions. The number of moles of chloride ions that comes from magnesium chloride is:

2 * 0.150 mol = 0.300 mol

Each mol of sodium chloride (NaCl) dissociates to give 1 mol of chloride ions. The number of moles of chloride ions that comes from sodium chloride is thus 0.750 mol

The total number of moles (n) of chloride ions in the solution is:

n = 0.400 mol + 0.300 mol + 0.750 mol

n = 1.450 mol

Now, we can use the molar mass of the chloride ion (M = 35.5 g/mol) to calculate the mass (m) of chloride ions in 1 liter of solution:

n = m/M ⇒ m = n*M

m = 1.450 mol * 35.5 g/mol

m = 51.475 g

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An physical properly I believe

Explanation: characteristics such as melting point boiling point color ider colored stuff etc all have physical properties

The two isotopes that can be used for the process of dating are Potassium-41, Potassium-39.

The term radiometric dating has to do with the process by which the age of a rock can be discovered. We know that rocks that are around us have been around for very many years. As a matter of fact, there are some of the rocks that could be regarded as being as old as the earth could be in itself.

We have to note that one of things that could be regarded as important in the use of any isotope for dating is that isotope must have a long half life. The fact that the isotope has a long half life means that it is able to remain long enough for it to be used in the study of a substance.

We know that most of the rocks are composed of potassium as part of the components of the rock. In that case, if a dating technique would involve the potassium atom then it is likely to be a successful one as it were.

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The molecular formula of diazomethane is CH₂N₂, and the main reason for its instability is precisely the fact that it can very easily evolve nitrogen, as nitrogen's triple bond is one of the strongest covalent bonds in nature, and the energy released in its formation is more than enough to compensate the energy lost in the breaking of C-N bonds. The Lewis structure of diazomethane with the formal charges is attached below.

To obtain the molecular formula of diazomethane, we can imagine that we have 100 g of it. Now we can calculate the number of moles (n) for each of the elements, using their respective masses (m) and molar masses (M = 12 g/mol for carbon, 1 g/mol for hydrogen, and 14 g/mol for nitrogen):

n = m/M

n(C) = 28.57 g / 12 g/mol

n(C) = 2.38 mol

n(H) = 4.80 g / 1 g/mol

n(H) = 4.80 mol

n(N) = 66.64 g / 14 g/mol

n(N) = 4.76 mol

We now divide each of these numbers with the smallest of them (2.38) to calculate the molar ratio of the elements:

carbon: 2.38 / 2.38 = 1

hydrogen: 4.80 / 2.38 = 2

nitrogen: 4.76 / 2.38 = 2

Now we use these numbers to get the empirical formula of diazomethane: CH₂N₂.

The molar mass of the empirical formula is:

12 g/mol + 2 * 1 g/mol + 2 * 14 g/mol = 42 g/mol

Since this value is equal to the molar mass given to us, that means that CH₂N₂ is also the molecular formula of diazomethane.

Answer: protons: 92

electrons: 92

1. neutrons: 234-92 = 142

2. Neutrons- 233-92 = 141

3. Neutrons 232-92= 140

Explanation:

Experimental pH indicates the pH obtained by directly measuring a specific sample with a pH meter.

The main difference between calculated and experimental pH is that calculated pH gives the pH obtained by solving the pH equation whereas experimental pH is measured directly with a pH meter. It is to indicate the value of a particular sample obtained.

Because microorganisms such as bacteria are sensitive to the concentration of hydrogen ions present in the environment, pH results will change over the course of an experiment. pH is affected by larger proteins, including enzymes. pH is a quantitative measure of the acidity or basicity of a solution while acidity is a qualitative measure of the acidic properties of a solution.

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By using the balanced reaction equation of ethane combustion, we can calculate that 12.8 L of carbon dioxide will be produced.

To calculate the answer to this, we need to write the balanced reaction equation:

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

Based on this, we can see that 2 moles of ethane produce 4 moles of carbon dioxide. Now, we need to calculate the number of moles (n) of ethane using its mass (m = 8.00 g) and its molar mass (M = 30.07 g/mol):

n = m/M

n = 8.00 g / 30.07 g/mol

n = 0.266 mol

Based on this, we can conclude that 2 * 0.266 mol = 0.532 mol of carbon dioxide was produced. Assuming that carbon dioxide acts as an ideal gas, we can use the ideal gas equation to calculate its volume:

PV = nRT ⇒ V = nRT/P

V - the volume of the gas

n - number of moles of gas (0.523 mol)

R - universal gas constant (0.08206 L*atm/K*mol)

T - temperature in Kelvins (25 °C = 298.15 K)

P - pressure (1.00 atm)

Now we plug all the known values into the equation:

V = 0.523 mol * 0.08206 L*atm/K*mol * 298.15 K / 1.00 atm

V = 12.8 L

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At 40°C 12.25 g potassium sulfate would be precipitated

Saturated solutions are those in which the maximum amount of solute has been dissolved. The solute precipitates out of the solution as more solute is added.

Solubility of potassium sulfate is shown as:

Solubility of potassium sulfate at 40 °C will be 15 g/100 g

It can be understand that at 40 °C 15 g of potassium sulfate would get completely dissolved in 100 of water.

46.0 g of potassium sulfate to 225 g water

Amount of potassium sulfate will get dissolve in 225 g of water at 40 °C will be:

15 g/100g ×225 g = 33.75 g

Amount of potassium sulfate precipitated by the solution can be determined by as follow:

= 39.0 g-33.75 g = 5.25 g

At 40 °C 5.25 g of potassium sulfate will get precipitate out from the solution which means that solution is saturated.

It is given that, the amount of potassium sulfate which is added :
46 g - 33.75 g = 12.25 g.

Therefore, at 40°C 12.25 g potassium sulfate would be precipitated.

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To solve this question, we need to look at the stoichiometric ratio between oxygen and SO₃, which in this case is 1:2

So 1 mole of O2 produces 2 moles of SO3.

Now we can use the rule of 3:

1 mole O2 --- 2 mole SO3

x mole O2 --- 8.46 moles SO3

2x = 1 x 8.46

x = 8.46/2

x = 4.23

Answer: 4.23 moles of O2

The volume of the standardized base used in the titration was 23.43 mL.

When performing titration, the volume of the standardized base titrant used in the burette is read first (this value doesn't have to be 0, as it depends on the titrator filling the burette). In this case, this value is 2.75 mL.

During the titration, the titrant level in the burette goes down, and when the endpoint is reached, this level can be read. In this experiment, the final volume is 26.18 mL.

The volume used in the titration is obtained by subtracting the starting value from the final volume:

26.18 mL - 2.75 mL = 23.43 mL

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Answer:

2.068

Explanation:

D = M/V

3.04 /1.47

= 2.068

The correct answer is that a) covalent bonds need to form between molecules. The process of polymerization to polybutene doesn't require any of the other given transformations.

The polymerization process of 1-butene to polybutene includes the homolytic cleavage of the double bond and the formation of new covalent bonds between the radical formed and another molecule of 1-butene. This means that there is no need for oxidation (option b), formation of additional double bonds (option c, although the resulting molecule could also undergo polymerization, but it would not result in the formation of polybutene), or exchange of hydrogen atoms between the molecules (option d).

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Answer: A. Covalent bonds would need to form between the molecules.

Explanation: Got 100 on edmentum

Once chewed and swallowed, the food will be digested and absorbed nutrients, while the rest of the food will be excreted through the body's feces. This digestion process can take about 24-72 hours.

The process of digestion of food in humans can be divided into two types, namely mechanical digestion and chemical (enzymatic) digestion. Mechanical digestion is the process of changing food from a large or coarse form to a smaller or finer form. The process takes place in the mouth with the help of teeth and tongue. The mechanical digestion process also occurs in the stomach with the help of peristaltic motion of the stomach wall, so that food is like being stirred. While the chemical digestion process is the process of converting food substances from complex forms into simpler forms with the help of digestive enzymes.

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Answer:

Option B is the right answer.

Option C is correct. reduce reactant concentrations. shorten the time the reaction is allowed to proceed.

The reaction rate normally increases as the temperature rises. With rising temperature, the average kinetic energy of the reactant molecules rises. The minimum energy needed for an effective collision will therefore be present in a higher percentage of molecules. With rising temperatures, molecules' kinetic energy rises. The possibility of a reaction rises as molecules move more quickly and collide more frequently. This speeds up the reaction. The average kinetic energy of the individual particles of the system increases with increasing temperature. Particles move faster and collide more often per unit time as the average kinetic energy increases, and they have more energy when they collide. Both of these factors speed up the reaction.

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Answer:

Its weight changes based on location, but its mass stays the same.

Explanation:

See attached worksheet.

Since warm water has more energy than cold water, its molecules move more quickly than those in cold water. Gradually both the water will have same temperature according to Principle of calorimetry.

Heat lost by the hot body = heat gained by the cold body

What is principle of calorimetry?

In a calorimeter, two different types of matter are in contact with one another, ideally a liquid and a solid. Both bodies are also at various temperatures. A higher-temperature object can transfer heat energy to a lower-temperature object thanks to this setup.

Heat transfer does not stop, nevertheless, until there is a state of thermal equilibrium between the bodies. The "rule of conservation of energy," which is represented by the principle of calorimetry, states that the total amount of heat absorbed by the cold object and the total amount of heat released by the hot object are equal.

Since warm water has more energy than cold water, its molecules move more quickly than those in cold water. Gradually both the water will have same temperature

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First, let's write the balanced chemical reaction:

2 H2O2 ---MnO2--> 2 H2O + O2

This reaction is a b. Decomposition Reaction of hydrogen peroxide.

Step 1. Let's transform 2.11 mg of H2O2 into moles using the following equation mole = mass / molar mass

Step 2. We are going to use the equation proportion to calculate the quantity in moles of each compound.

Step 3. We are going to transform moles into grams of each compound using the following equation: mass = mole x molar mass

Step 1.

We need to transform 2.11 mg to g. We just need to divide by 1000,

So: 2.11 x 10^-3 g of H2O

mole = 2.11 x 10^-3/34.02

mole = 6.20 x 10^-5 moles

Step 2.

2 moles of H2O2 ---- 2 moles of H2O

6.20 x 10^-5 moles ---- x moles of H2O

x = 6.20 x 10^-5 moles of H2O

2 moles of H2O2 ---- 1 moles of O2

6.20 x 10^-5 moles ---- x moles of O2

x = 3.10 x 10^-5 moles of O2

Step 3.

molar mass of O2 : 32 g/mol

molar mass of H2O: 18 g/mol

mass of H2O = 6.20 x 10^-5 x 18 = 1.12 x 10^-3 g

mass of O2 = 3.10 x 10^-5 x 32 = 9.92 x 10^-4 g

Answer:

freezing points hope it helps u

Distillation is a process used to separate a mixture of liquids based on different freezing points. Therefore, option C is correct.

Distillation is the process of turning a liquid into a vapor, which is then condensed back into a liquid state. The simplest illustration of it is when steam from a kettle condenses into drops of distilled water that are left on a cold surface.

In general, distillation is the process of vaporizing a liquid to its boiling point, then condensing it back into a liquid to separate it from impurities or other solutes.

Among the many industrial uses of distillation are the production of alcoholic drinks, water purification, and oil refining. Distillation is a physical procedure that removes desired pure compounds from an initial source using heat and other techniques.

Thus, option C is correct.

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Answer: Physical - Color, density, boiling/melting point, magnetism, texture, and odor

Chemical - reactivity, combustibility, color change, and temperature change

Explanation:

Physical properties are changes to a substance that can be reversed and refer to its state at the time. Chemical properties are properties that are observable during or after a chemical reaction and cannot be reversed since the reaction has changed the state of the substance.

The heat released by metal and added to water is the same which is 1039.83 joule.

The equilibrium condition of the system depends on the heat released from both gold and water. The total heat received by the system will equal to total heat released by objects. It should follow

Q released = Q received

The heat can be defined by

Q = m . c . ΔT

where Q is heat, m is mass, c is the specific heat constant and ΔT is the change in temperature.

The given parameters are

m = 17.27 g = 0.01727 kf

T1 = 92 ⁰C

T2 = 25.1 ⁰C

c = 900 J/kg⁰C

By substituting the given parameters, we can calculate the heat

Q = m . c . ΔT

Q = 0.01727 . 900 . (92 - 25.1)

Q = 1039.83 joule

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Answer:

see the explanation

Explanation:

1. IV

2. VI

3. II

4. IV

5. II

6. VI

7. IV

8. III

9. II

10. I

11. I

12. V

13. VII

14. III

15. I

16. III

17. V

18. IV

19. V

20. III

21. IV

22. III

23. IV

24. VII

25. II

26. II

27. III

Answer

%Yield = 87.2%

Explanation

Given:

mass of NH3 reacted = 73 g

mass of H2O produced = 101 g

We know:

molar mass of NH3 = 17,031 g/mol

molar mass of water = 18.01528 g/mol

Required: % Yield

Solution:

The formula used to calculate the percentage yield is:

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

The actual yield of H2O produced = 101 g

Now lets calculate the theoretical yield first.

First find the number of moles of NH3, and use stoichiometry to find the theoretical mass of water.

n = m/M n is the moles, m is the mass and M is the molar mass.

n = 73/17,031 g/mol

n = 4.29 mol

Using the stoichiometry, there molar ratio between NH3 and H2O is 4:6

Therefore the moles of H2O = 4.29 x (6/4)

n of H2O = 6.43 mol

The theoretical mass can then be calculated:

m = n x M

m = 6.43 mol x 18.01528 g/mol

m = 115.83 g

%Yield = (101 g/115.83)*100

%Yield = 87.2%

Answer:

Therefore the number of oxygen atoms will be. 033 × 10 23 atoms.