1. For 280. 0 mL of a buffer solution that is 0. 225 M in HCHO2 and 0. 300 M in KCHO2, calculate the initial pH and the final pH after adding 0. 028 mol of NaOH. ( Ka(HCHO2)=1. 8×10−4. ) Express your answers to two decimal places. Enter your answers numerically separated by a comma.

2. For 280. 0 mL of a buffer solution that is 0. 295 M in CH3CH2NH2 and 0. 225 M in CH3CH2NH3Cl, calculate the initial pH and the final pH after adding 0. 028 mol of NaOH. ( Kb(CH3CH2NH2)=5. 6×10−4. )

Express your answers to two decimal places. Enter your answers numerically separated by a comma.

ANSWER

The number of moles of Pb(SO4)2 is 1.5 moles

EXPLANATION

Given that;

The mass of Li2SO4 is 330g

Follow the steps below to find the moles of Pb(SO4)2

Step 1; Write the balanced equation of the reaction

Step 2; Find the number of moles of Li2SO4 using the below formula

Recall, that the molar mass of Li2SO4 is 109.94 g/mol

The number of moles of Li2SO4 is 3.00 moles

Step 3; Find the number of moles of Pb(SO4)2 using a stoichiometry ratio

In the above equation of the reaction, 1 mole Pb(SO4)2 reacts to give 2 moles LiSO4

Let the number of moles of Pb(SO4) be x

Therefore, the number of moles of Pb(SO4)2 is 1.5 moles

Answer:

Lead(IV) iodide

Explanation:

Answer:

Plasmid #50548

Explanation:

Explanation: the answer plant seeds

not skin

Yes, electromagnetic waves are characterized by their wavelengths. Wavelength is the distance between two consecutive peaks or troughs of a wave. Electromagnetic waves include radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.

The Each type of electromagnetic wave has a different wavelength and frequency. Radio waves have the longest wavelengths, ranging from hundreds of meters to several kilometers. Microwaves have shorter wavelengths, typically measured in centimeters. Infrared radiation has wavelengths ranging from a few micrometers to several millimeters, while visible light has wavelengths between 400 and 700 nanometers. Ultraviolet radiation has even shorter wavelengths, measured in nanometers, while X-rays and gamma rays have the shortest wavelengths, ranging from a few picometers to a few tenths of an angstrom. The wavelength of an electromagnetic wave determines its properties, such as its energy and the type of interaction it has with matter. For example, longer wavelengths of radio waves can travel long distances and penetrate through walls, while shorter wavelengths of X-rays can penetrate through the body and create images of bones and organs. The study of electromagnetic waves and their wavelengths is important in many fields, including astronomy, telecommunications, medicine, and environmental science.

learn more about radiation here.

https://brainly.com/question/13934832

#SPJ11

A chemical equation is a statement using chemical formulas expresses both the identities and the relative quantities of the reactants and products involved in a chemical or physical change. The correct answer is B.

An expression of the identities and relative quantities of the reactants and products involved in a chemical or physical transformation is called a chemical equation. Chemical equations are statements made using chemical formulas.

In chemical equations, variables like the direction of a reaction and the physical states of the reacting parties are represented by symbols. In 1615, the French chemist Jean Beguin created the first chemical equation.

Chemical equations, such as the one below, can be used to depict chemical reactions on paper (for the reaction between hydrogen gas and oxygen gas to form water).

To know more about chemical equations, click the link given below:

brainly.com/question/19626681

#SPJ4

The reaction : Pb(NO3)₂ + KCl ---->  PbCl₂ + KNO₃ , the specie which will precipitate in the queous solution is the correct option is D)  PbCl₂ .

The complete balanced equation is as :

Pb(NO3)₂(aq) + 2KCl(aq) ---->  PbCl₂(s) + 2KNO₃(aq)

The potassium ion belongs to the 1 group. The 1 group salt are generally soluble salts. Therefore the KCl is soluble in water. Most of the salt containing the nitrates ion are soluble in the salt. Therefore , the Pb(NO3)₂ and KNO₃ are soluble in the aqueous solution. The salts of lead halide are not soluble.

Therefore, the PbCl₂ will form the precipitate in the chemical reaction.

To learn more about precipitate here

https://brainly.com/question/27809742

#SPJ4

Answer:

B) A person activates a cold pack by hitting it against a surface.

C) A rechargeable battery is plugged in to charge.

D) Heat is used to separate a compound into its elements.

Explanation:

Chemical reactions that absorb energy are called endothermic reactions. Endothermic reactions absorb energy in the form of heat, light, or electricity, which causes the temperature of the system to decrease.

A) Plants use sunlight and atmospheric gases to make food through photosynthesis, which is an endothermic reaction that absorbs energy in the form of light.

B) A person activates a cold pack by hitting it against a surface, which triggers an endothermic reaction that absorbs heat from the surroundings, causing the cold pack to become cold.

C) A rechargeable battery is plugged in to charge, which involves an endothermic reaction that absorbs electrical energy, converting it into chemical energy that is stored in the battery.

D) Heat is used to separate a compound into its elements through heating, which is an endothermic reaction that absorbs heat from the surroundings, causing the temperature of the system to decrease.


ALLEN

Explanation:

Since the starting mass of the rock was 50 grams of the radioactive isotope, and we now have 12.5 grams of the radioactive isotope, we can see that the rock has undergone 2 half-lives.

The amount of time needed for the reactant concentration to drop to half its original value is known as the half-life of a reaction. A first-order reaction's half-life is independent of the reactant's concentration.

The total mass of the rock would be 100 grammes if it initially included 50 grammes of a radioactive isotope and 50 grammes of a non-radioactive element. Let's suppose that the radioactive isotope's half-life is known.

At one half-life, only 25 grammes of the radioactive isotope and 75 grammes of the non-radioactive element would remain after half of the radioactive isotope has decayed.

Following two half-lives, 12.5 grammes of the radioactive isotope and 87.5 grammes of the non-radioactive substance would remain after half of the remaining 25 grammes of the radioactive isotope had decayed.

Since the starting mass of the rock was 50 grams of the radioactive isotope, and we now have 12.5 grams of the radioactive isotope, we can see that the rock has undergone 2 half-lives.

To know more about isotope visit:-

https://brainly.com/question/11904263

#SPJ1

During hyperventilation, the pH of the blood increases (becomes more alkaline), while the carbon dioxide (CO2) level decreases. These changes are consistent with the prediction.

Hyperventilation refers to an increased rate and depth of breathing, leading to the removal of excess carbon dioxide from the body. As a result, the concentration of carbon dioxide in the blood decreases. Carbon dioxide reacts with water to form carbonic acid (H2CO3), which dissociates into bicarbonate ions (HCO3-) and hydrogen ions (H+). By reducing the carbon dioxide level, there is less production of H+ ions, resulting in an increase in blood pH, making it more alkaline.

The observed changes in pH and carbon dioxide levels during hyperventilation are consistent with the predicted response. Increased ventilation causes more carbon dioxide to be expelled from the body, shifting the equilibrium of the carbonic acid-bicarbonate buffer system. As a consequence, the pH of the blood rises, leading to alkalosis. These changes can be confirmed through blood gas analysis or other diagnostic tests.

learn more about carbon dioxide here:

https://brainly.com/question/3049557

#SPJ11

Answer:

1.BaCO3 2.MgBr2 3.aluminum and oxygen 4.Potassium chloride

Explanation:

It represents an amine group.

Answer:

= 2 x 10 ²⁴ sulfur atoms in the compound.

Explanation:

There are 3.6 X 10^20 atoms of iron in the compound

Divide the number of iron atoms by 1.8 X 10^-4 to find the number of sulfur atoms in the compound.​

therefore,

= 3.6 X 10²⁰

  1.8 X 10⁻⁴

= 2 x 10 ²⁴  sulfur atoms in the compound.​

The simplest straight-chain alkynes containing seven to twelve carbons are:

1. Heptyne (7 carbons)

2. Octyne (8 carbons)

3. Nonyne (9 carbons)

4. Decyne (10 carbons)

5. Undecyne (11 carbons)

6. Dodecyne (12 carbons)

Here are the structures and names of the simplest straight-chain alkynes containing seven to twelve carbons:

1. Heptyne:

  Structure: H-C≡C-C≡C-C≡C-C≡C-H

  Name: 1-Heptyne

2. Octyne:

  Structure: H-C≡C-C≡C-C≡C-C≡C-C≡C-H

  Name: 1-Octyne

3. Nonyne:

  Structure: H-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-H

  Name: 1-Nonyne

4. Decyne:

  Structure: H-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-H

  Name: 1-Decyne

5. Undecyne:

  Structure: H-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-H

  Name: 1-Undecyne

6. Dodecyne:

  Structure: H-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-C≡C-H

  Name: 1-Dodecyne

Learn more about alkynes at https://brainly.com/question/27937735

#SPJ11

Answer:

the answer is b

hope this helps you!!

Have a lovely day!

-millie :D

Answer:

300 dm³

Explanation:

According to the information given in this problem, SO₂ is 24 dm³/mol at rtp.

We are trying to find the volume of 12.5 moles of SO₂, so we can do the following math to solve:

12.5 mol SO₂ × 24 dm³/mol ⇒ mol cancels out, leaving us with dm³

300 dm³

Therefore, the volume occupied is 300 dm³

Answer:

1240 mmHg

Explanation:

Since volume is being held constant, we can use the following variation of the Ideal Gas Law to find the new pressure.

\(\frac{P_1}{T_1N_1}=\frac{P_2}{T_2N_2}\)

In the equation, "P₁", "T₁", and "N₁" represent the initial pressure, temperature, and moles. "P₂", "T₂", and "N₂" represent the final pressure, temperature, and moles. Your answer should have 3 sig figs to match the sig figs of the given values.

P₁ = 825 mmHg                            P₂ = ? mmHg

T₁ = 303 K                                     T₂ = 273 K

N₁ = 1.50 moles                             N₂ = 1.50 + 1.00 = 2.50 moles

\(\frac{P_1}{T_1N_1}=\frac{P_2}{T_2N_2}\)                                                     <----- Formula

\(\frac{825 mmHg}{(303K)(1.50 moles)}=\frac{P_2}{(273 K)(2.50 moles)}\)                   <----- Insert values

\(\frac{825 mmHg}{454.5}=\frac{P_2}{682.5}\)                                               <----- Simplify denominators

\(1.815=\frac{P_2}{682.5}\)                                                     <----- Simplify left side

\(1238.86 mmHg={P_2}\)                                          <----- Multiply both sides by 682.5

\(1240 mmHg={P_2}\)                                              <----- Apply sig figs

Answer:1240

Explanation:

Answer:

The reactivity order reflects both the strength of the C-X bond and the stability of X(-) as a leaving group and leads to the general conclusion that alkyl iodides are the most reactive members of this functional class

The concentration of ammonia gas at equilibrium is 0.30 mM.

To calculate the concentration of ammonia gas (\(NH_3\)) at equilibrium, we can use the equilibrium constant (K) and the partial pressure of \(H_2S\) gas (\(PH_2S\)).

The balanced equation for the reaction is:

\(NH_4HS\)(s) + \(NH_3\)(g) + \(H_2S\)(g) ⇌ \(NH_4HS\)(s) + \(H_2S\)(g)

The equilibrium constant expression is given by:

K = ([\(NH_4HS\)] * [\(NH_3\)] * [\(H_2S\)]) / ([\(NH_4HS\)] * [\(H_2S\)])

Since NH4HS is a solid, its concentration remains constant and does not affect the equilibrium expression. Therefore, we can simplify the equation to:

K = [\(NH_3\)] * [\(H_2S\)] / [\(H_2S\)]

Given that K = 3.0x\(10^{(-4)\) and \(PH_2S\) = 0.370 atm, we can substitute these values into the equation:

3.0x\(10^{(-4)\) = [\(NH_3\)] * 0.370 / 0.370

Simplifying further:

[\(NH_3\)] = 3.0x\(10^{(-4)\) mol/L

To express the concentration in millimolar (mM), we multiply by 1000:

[\(NH_3\)] = 3.0x10\(^{(-1)\) mM

For more such questions on ammonia, click on:

https://brainly.com/question/14854495

#SPJ11

Answer: ^_^

Explanation:

its because during day time the ball becomes heated up and the air inside it try to come out as the heat air always try to go up swelling up the ball,

so in the evening when the air cools down the ball too cools down and air inside it also cools down making the ball feel soft,

Therefore, a football feels hard on a hot day but feels softer in the evening​

Hope it helped u,

pls mark as the brainliest

^_^

Answer:

its because during day time the ball becomes heated up and the air inside it try to come out as the heat air always try to go up swelling up the ball,

so in the evening when the air cools down the ball too cools down and air inside it also cools down making the ball feel soft,

Therefore, a football feels hard on a hot day but feels softer in the evening​

Hope it helped u,

pls mark as the brainliest

Explanation:

Number of protons number of electrons neutral atom cation anion neutral atom cation anion neutral atom cation anion number of proton is 7 So, atomic number is 7 atomic number is 7 for N charge.

Number of proton is 7 So, atomic number is 7 atomic number is 7 for N charge = number of proton - number of electron  = 7 - 10  = -3 So, this is anion A .

Protons are the positively charged particles that are inside the nucleus of an atom. The protons are pushed apart by the electromagnetic force but pulled together by the strong force, which is stronger over short distances .

Cations are positively-charged ions (atoms or groups of atoms that have more protons than electrons due to having lost one or more electrons). Anions are negatively-charged ions (meaning they have more electrons than protons due to having gained one or more electrons).

The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

Electron, proton, neutron are subatomic particles which build the atom. The atom consists of a central nucleus containing neutron and proton. Electrons revolve around the nucleus. Electrons are negatively charged, proton is positively charged and neutron is neutral.

Learn more about protons here:-

brainly.com/question/1252435

#SPJ4

Answer:

37.1 calories.

Approximately, 37.1 = 40 calories.

Explanation:

So, without mincing words let's dive straight into the solution to the question above.

We are given the following parameters which are going to help in solving this particular Question.

The mass of broccoli = 86g of broccoli, mass of carbohydrates present = 6g of carbohydrates, the mass of protein present = 2.6g of protein and the mass of fat present = 0.3g of fat.

Therefore, the nutritional energy content (in Calories) = (6 × 4) + (2.6 × 4) + (0.3 × 9) = 10.4 + 24 + 2.7 = 37.1

Hence, the nutritional energy content (in Calories) = 37.1 calories.

Approximately, 37.1 = 40 calories.

To find the number of moles represented by a certain number of particles, you can use Avogadro's number and the concept of molar mass.

Avogadro's number (symbolized as N_A) is a fundamental constant that represents the number of particles (atoms, molecules, ions, etc.) in one mole of a substance. It is approximately equal to 6.022 × 10²³ particles/mole.

Molar mass is the mass of one mole of a substance and is expressed in grams/mole. It represents the sum of the atomic masses or molecular masses of the constituent particles in a substance.

To calculate the number of moles, you can follow these steps;

Determine the number of particles you have (atoms, molecules, ions, etc.).

Identify the molar mass of the substance or the average molar mass if it's a mixture.

Divide the number of particles by Avogadro's number to convert them into moles. The formula is:

Moles = Number of Particles / Avogadro's number

Moles = Number of Particles / (6.022 ×10²³ particles/mole)

The result will give you the number of moles represented by the given number of particles.

To know more about Avogadro's number here

https://brainly.com/question/24175158

#SPJ4

--The given question is incorrect, the correct question is

"Explain how you would find the number of moles that are represented by a certain number of representative particles."--

The balanced equation of the given chemical reaction is as follows: NO(g) + O₂(g) ⟶ N₂O₃(g). The rate of formation of N₂O₃ is given as 0.472 M/s.

To find out the rate at which NO is decreasing, we need to determine the rate of the consumption of NO.

We know that NO is one of the reactants, and it is being used up in the chemical reaction.

Thus, the rate of decrease in the concentration of NO can be calculated by multiplying the rate of formation of N₂O₃ by the stoichiometric coefficient of NO from the balanced equation.

The stoichiometric coefficient of NO in the balanced chemical equation is 1. Therefore, the rate of decrease in the concentration of NO is given as follows:

Rate of decrease in the concentration of NO = rate of formation of N₂O₃ × Stoichiometric coefficient of NO= 0.472 M/s × 1= 0.472 M/s.

Therefore, the rate of decrease in the concentration of NO is 0.472 M/s.

Learn more about the rate:
https://brainly.com/question/17206790

#SPJ11

The order of solubility from most to least can be given as carbonate>sulfate>iodate>chloride. Carbonates are the most soluble.

The maximum amount of a material that may dissolve in another is known as its solubility. A saturated solution is created when a solvent can dissolve its maximum quantity of solute before reaching equilibrium. A supersaturated solution results when extra solutes are dissolved past its equilibrium solubility point under specific circumstances.

Dissolution is the action of disintegrating. In contrast to the speed of solution, which specifies how rapidly a molecule dissolves in a solvent, solubility is not a feature of matter. The order of solubility from most to least can be given as carbonate>sulfate>iodate>chloride.

Therefore,  the order of solubility from most to least can be given as carbonate>sulfate>iodate>chloride.

To know more about solubility, here:

https://brainly.com/question/14366471

#SPJ1

If the volume of occupied by the gas molecules s were doubled, then the pressure exerted by gas molecules will be doubled. So, correct answer is option (c).

Boyle's Law: As the pressure of a gas increases, the volume of gases decreases because the gases are forced closer together. Conversely, as the pressure of the gas decreases, the volume of the gas increases because the gas can now travel farther. The empirical relation asserts that the pressure (P) of a given quantity of gas changes inversely with its volume (V) at constant temperature; i.e., PV = k,

where, k --> constant. Now, we have,

volume is doubled. Using above relation as if volume is doubled the pressure also doubled.

For more information about Boyle's law, refer:

https://brainly.com/question/12817429

#SPJ4

Answer:

jjijjĵjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjhh

Explanation:

ju8uhtyù

An exothermic process is one that gives off heat.

Explanation:

This heat is transferred to the surroundings. An endothermic process is one in which heat has to be supplied to the system from the surroundings.