Acetic acid has a Ka of 1.8 * 10-5. Three acetic acid/acetate buffer solutions, A, B, and C, were made using varying concentrations: acetic acid ten times greater than acetate, acetate ten times greater than acetic acid, and acetate=acetic acid.
Match each buffer to the expected pH. pH = 3.74 ; pH = 4.74 ; pH = 5.74
Part B: How many grams of dry NH4Cl need to be added to 2.30 L of a 0.600 M solution of ammonia, NH3, to prepare a buffer solution that has a pH of 8.71? Kb for ammonia is 1.8 * 10-5.
Express your answer with the appropriate units.

Answer:

HOFO = (0, 0, +1, -1)

Explanation:

The formal charge (FC) can be calculated using the following equation:

[tex] FC = V - N - \frac{1}{2}B [/tex]

Where:

V: are the valence electrons

N: are the nonbonding electrons

B: are the bonding electrons

The arrange of the atoms in the oxyacid is:

H - O₁ - F - O₂

Hence, the formal charge (FC) on each of the atoms is:

H: FC = 1 - 0 - 1/2*(2) = 0            

O₁: FC = 6 - 4 - 1/2*(4) = 0        

F: FC = 7 - 4 - 1/2*(4) = +1

O₂: FC =  6 - 6 - 1/2*(2) = -1

We can see that the negative charge is in the oxygen instead of the most electronegative element, which is the F. This oxyacid is atypical.  

I hope it helps you!

Answer:

The answer to your question is  131.43 grams of MgBr₂

Explanation:

Data

number of grams = ?

number of atoms = 4.3 x 10²³

Molecule = MgBr₂

Process

1.- Calculate the molar mass of MgBr₂

MgBr₂ = 24.3 + (79.9 x 2) = 24.3 + 159.8 = 184.1 g

2.- Use proportions to calculate the number of atoms

               184.1 g of MgBr₂ -------------- 6.023 x 10²³ atoms

                  x                       -------------- 4.3 x 10²³ atoms

                            x = (4.3 x 10²³ x 184.1) / 6.023 x 10²³

                            x = 7.92 x 10²⁵ / 6.023 x 10²³

                           x = 131.43 grams

Answer:

Explanation:

Glycolysis is the process of breakdown of  glucose into two 3-carbon molecules called pyruvate. The energy released during glycolysis is used to make ATP.

Enolase is the enzyme  which plays very important role in glycolysis. In the 9th step of glycolysis, Enolase converts  2-phosphoglycerate into phosphoenolpyruvate.

This reaction of conversion of  2-phosphoglycerate to phosphoenolpyruvate is a reversible dehydration reaction.

Fluoride inhibits enolase, so when enolase is become non-functional then there is no convertion of 2-phosphoglycerate  to phosphoenolpyruvate, so the concentraion of 2-phosphoglycerate is increases by the addition of fluoride.

1.95  or 2  is the molarity of a 45.3g sample of KNO3 (101g) dissolved in enough water to make a 0.225L solution.

The correct answer is option b

Explanation:

Data given:

mass of KN[tex]O_{3}[/tex] = 45.3 grams

volume = 0.225 litre

molarity =?

atomic mass of KNO3 = 101 grams/mole

molarity is calculated by using the formula:

molarity = [tex]\frac{number of moles}{volume of the solution}[/tex]

first the number of moles present in the given mass is calculated as:

number of moles = [tex]\frac{mass}{atomic mass of 1 mole}[/tex]

number of moles = [tex]\frac{45.3}{101}[/tex]

0.44 moles of KNO3

Putting the values in the equation of molarity:

molarity = [tex]\frac{0.44}{0.225}[/tex]

molarity = 1.95

It can be taken as 2.

The molarity of the potassium nitrate solution is 2.

The Michael drove 648,000 m.

Explanation:

It is given that the time taken by Michael, that is t = 36000 s

Speed is nothing but distance traveled by the time taken in seconds. Its unit is  m/s.

Here we have the speed in km/hr, we have to convert it to m/s as,

1 km = 1000 m

1 hr = 3600 s

So it is converted as,

[tex]$\frac{65 \times 1000}{3600}[/tex]  

= 18 m/s

Now we have the speed in m/s.

18 m/s = [tex]$\frac{x m}{36000s}[/tex]

We can find the distance x as = 18 m/s ×36000 s = 648,000 m

So the Michael drive 648,000 m.

Answer:

0.0294

Explanation:

Answer:

The answer to your question is 2 moles

Explanation:

Data

mass of H₂O = 36 g

moles of H₂O = ?

Process

1.- Calculate the molar mass of water (H₂O)

H₂O = (1 x 2) + (16 x 1) = 2 + 16 = 18 g

2.- Use proportions and cross multiplication to find the answer.

               18 g of H₂O ---------------- 1 mol

               36 g of H₂O --------------- x

                     x = (36 x 1) / 18

                     x = 36/18

                     x = 2 moles

Answer:

[tex]Q_{iron} = -32730.083\,J[/tex]

Explanation:

By the First Law of Thermodynamics, the piece of iron and water reach thermal equilibrium when both have the same temperature. The heat released by the piece of iron is received by the water. That is to say:

[tex]Q_{iron} = -Q_{w}[/tex]

[tex]Q_{iron} = (93.64\,g)\cdot \left(4.186\,\frac{J}{kg\cdot ^{\textdegree}C} \right)\cdot (7\,^{\textdegree}C-90.5\,^{\textdegree}C)[/tex]

[tex]Q_{iron} = -32730.083\,J[/tex]

Answer:

The elements in__Group_ 0 of the Periodic Table are called the_noble__gases. They are generally __unreactive_. because they have a__full_outer shell of electrons. So they do not need to gain__lose_or share _electrons_ with other atoms.

Pressure is inversely related to volume. Temperature is inversely related to moles. Volume is inversely related to pressure. Moles are inversely related to temperature.

Explanation:

The ideal gas law is represented mathematically as: PV=nRT. P- pressure, V- volume, n-number of moles of gas, R- ideal gas constant, T- temperature.

The ideal gas law is used as a prediction of the behavior of many gases, when subjected to different conditions.

An increase in the pressure or volume, decreases the number of moles and temperature of the gas.

Empirical laws that led to generation of the ideal gas laws, considered two variables and keeping the others constant. This empirical laws include, Boyle's law, Charles's law, Gay Lusaac's law and Avogadro's law.

Answer:

Pressure is

✔ inversely related to volume

.

Temperature is

✔ inversely related to moles

.

Volume is

✔ inversely related to pressure

.

Moles are

✔ inversely related to temperature

.

Identify the ideal gas law equation.

✔ PV=nRT

Explanation:

Answer:

Dynes

Explanation:

Dynes is not a unit of pressure. Dynes is CGS unit of force.

Answer: E. Occurs when methane gas is burned.

Explanation:

A chemical change occurs when matter undergoes a change to form a new substance with different chemical properties, and the reaction is usually not reversible.

In the case of burning methane gas (CH4) ,oxygen and methane are the reactants, while the new substance formed from the reaction are carbondioxide (CO2) and water (H2O) .

A chemical change, involving a chemical reaction and the formation of new substances, occurs when methane gas is burned. Therefore, option e is the correct answer.

In the provided options, the chemical change occurs when methane gas is burned (option e). A chemical change involves a chemical reaction, with the formation of new substances that have different properties from those of the original substances. In the case of burning methane, the chemical reaction can be represented as CH4 + 2O2→ CO2 + 2H2O. As a result of this reaction, methane (CH4) and oxygen (O2) are transformed into carbon dioxide (CO2) and water (H2O), which are completely distinct entities with different properties.

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Tarnished silver ware is cleaned by placing it in an aluminium pan as E°cell is positive.

Explanation:

The tarnish silver due to silver sulphate is removed by placing the tarnished ware in an aluminium pan. Certainly, aluminium is a stronger reducing agent than silver. Hence, it reduces the silver ions(Ag+) to metallic silver. The silvery white white colour will slowly get deposited on the walls of silwer ware and then the tarnish will be removed.

Al(s)+ 3Ag+ (aq)→ Al3+ (aq)+ 3Ag(s)

E° cell = E ° cathode - E° anode

 = (-0.71)- (-1.66) = 0.95 V is positive.

Hence, the reaction is feasible and the tarnish will be removed.

The electrochemical principle behind the procedure is aluminum is a strong reducing agent.

Electrochemical reaction is the reaction in which the electrons flow between a solid electrode.

The reaction is [tex]Ag^2S (s) + 2e- 2Ag (s) + S-2 (aq) is -0.71 V[/tex]

E° cell = E ° cathode - E° anode

(-0.71)- (-1.66) = 0.95 V is positive.

Thus, the  electrochemical principle behind the procedure is aluminum is a strong reducing agent.

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Answer:

When heating, the temperature is increased, therefore, the average kinetic energy is increased so the molecules will start moving more rapidly.

Explanation:

Hello,

Kinetic molecular theory is based on a series of specific statements:

- Gases are constituted by a raft of particles that are considered as both hard and spherical bodies under a state of constant and random movement.

- The particles are constantly moving in a straight line until they collide to each other or against walls of the container.

- There is no force of attraction nor repulsion among gas particles or among the particles and the walls of the container.

- Collisions are said to be perfectly elastic.

- The average kinetic energy of a raft of gas particles is temperature-dependent only.

- The higher the temperature the higher the average kinetic energy of the gas and the other way around.

In such a way, considering the last two statements, when heating, the temperature is increased, therefore, the average kinetic energy is increased so the molecules will start moving more rapidly in comparison to the initial state.

Best regards.

Answer:

C-18

Explanation:

Step one follow order of operations

Add and subtract from left to right(-5)+(7)=2-(-4)+(12)

STEP 2

Apply negative Rule -(-4)=+4=2+4+(12)

then add 2+4+12=18

Answer:

The answer to your question is below

Explanation:

The information given is not important to determine if the bond is ionic.

An ionic bond is when a metal and a nonmetal combine or when the electronegativity of the elements is higher than 1.7.

In this example, lithium is a metal and fluorine is a nonmetal so they will form an ionic compound.

Lithium is in group lA so it has 1 electron in its outermost shell.

Fluorine is in group VIIA so it has 7 electrons in its outermost shell.

Lithium donates one electron to fluorine so they become stable.

Answer:

The answer to your question is 9.034 x 10²³ molecules

Explanation:

Data

number of molecules = ?

number of moles = 1.50

Process

To solve this problem, use Avogadro's number. This number relates 1 mol of a substance to 6.023 x 10²³ molecules.

                          1 mol of CO₂ ---------------  6.023 x 10 ²³ molecules

                          1.5 moles of CO₂ ----------   x

                                x = (1.5 x 6.023 x 10²³) / 1

                                x = 9.034 x 10²³ molecules

The gases eventually reach the Earth's surface through rain. Hence option A is correct.

Volcanic eruption is defined as when a volcano erupts, sometimes violently spewing lava and gas into the air. Volcanoes erupt with a powerfully destructive mixture of ash, lava, hot, toxic gases, and rock. Explosions from volcanoes have claimed lives. Volcanic eruptions can bring forth additional health risks such wildfires, floods, mudslides, electricity outages, and contaminated drinking water.

During a volcanic eruption, water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide make up 90% of the gas molecules released (SO2). The remaining one percent is made up of trace amounts of hydrogen sulfide, carbon monoxide, hydrogen chloride, hydrogen fluoride, and other small gas species.

Thus, the gases eventually reach the Earth's surface through rain. Hence option A is correct.

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Answer:

The correct option is;

S is more nucleophiclic than O because S is larger than O therefore S is less well solvated than O

Explanation:

Here we have

As the size of atoms increases, the basicity increases and the nucleophilicity increases. Therefore since S is larger than O it is more nucleophilic than O.

Also we have smaller nucleophiles are more solvated than larger nucleophiles therefore S is less well solvated than O.

Which gives the correct answer as;

S is more nucleophiclic than O because S is larger than O therefore S is less well solvated than O.

A nucleophile is a molecule or ion that donates an electron pair to form a new covalent bond, while an electrophile accepts an electron pair to form a new covalent bond.

A nucleophile is a molecule or ion that donates an electron pair to form a new covalent bond. An electrophile is a molecule or ion that accepts an electron pair to form a new covalent bond. Nucleophiles are typically more nucleophilic than electrophiles due to the presence of a lone pair of electrons. The nucleophilicity of a nucleophile can be influenced by factors such as electronegativity and steric hindrance.

For example, in a reaction between a nucleophile and an electrophile, the nucleophile attacks the electrophilic center, forming a new bond and displacing a leaving group. The nucleophile is usually a lone pair donor, such as an anion or a molecule with a lone pair of electrons, while the electrophile is typically an atom or molecule with a partially positive charge.

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Answer:

Doctors began to use sterilized medical

instruments; European and American

hospitals developed a standard of

cleanliness.

Explanation:

Medical advancements were pivotal in allowing Europeans to sustain imperial control in tropical regions by preventing diseases that previously hindered colonization. Additionally, medical superiority was used to justify imperialism and perpetuate colonial domination, although it often led to health disparities favoring the colonial elite.

Medical advances played a critical role in facilitating European imperial expansion into regions such as Africa, the Middle East, and Asia. The improvements in healthcare and the ability to manage and prevent tropical diseases allowed European soldiers and administrators to survive in environments that were previously inhospitable due to diseases like malaria. The global homogenization of disease also meant that European powers brought infectious diseases to colonized areas, which often had devastating effects on the local populations.

Technology afforded Europeans with advanced weapons and transportation, but medical technology specifically enabled them to maintain their imperial presence overseas. This, along with ideologies like Social Darwinism, justified their actions and supported the spread of imperialism. It also resulted in the unequal improvement of healthcare systems in colonized regions, favoring the urban elite over the rural poor.

Moreover, European dominance in medicine was used to demonstrate their supposed superior science. While European medical practices sometimes improved health outcomes for colonized populations, they also exploited these populations for research and reinforced colonial domination. Infrastructure, such as railroads and irrigation canals, while beneficial for the imperial powers' economic interests, also contributed to the spread of disease. In some cases, the introduction of diseases by Europeans led to high mortality rates among indigenous peoples, weakening resistance to imperial control.

0.405M is the molarity of a solution made from 275 g of CuSO[tex]_4[/tex] dissolved in enough water to make 4.25 L.

The amount of moles of solute multiplied by the amount of liters of solutions is the definition of molarity, a concentration unit in chemistry. It is crucial to comprehend how it is calculated as well as when to employ it in comparison to other units because it ranks among the most widely used concentration units.

A chemical solution's concentration is measured in molarity (M). It refers to the moles of solvent /100 liters of solution. To be clear, this is not the same as the liters of solvents (a common mistake).

molarity = moles of solute/ volume of solution

=(275 /159.6)1/4.25

= 0.405M

Therefore, 0.405M is the molarity of a solution made from 275 g of CuSO[tex]_4[/tex] dissolved in enough water to make 4.25 L.

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Final answer:

To calculate the molarity of a CuSO₄solution, first find the moles ofCuSO₄ by dividing its mass by the molar mass, then divide by the volume of the solution thats molarity is 0.0073225M.

Explanation:

To find the molarity of a solution made from 275 g oF CuSO₄ dissolved in enough water to make 4.25 L, follow these steps:

Calculate the number of moles of CuSO₄. Using the molar mass of CuSO₄ (159.61 g/mol), divide the mass of the solute by its molar mass:
moles ofCuSO₄= 275 g / 159.61 g/mol.

Divide the number of moles of CuSO₄ by the volume of the solution (in liters) to find the molarity:
Molarity (M) = moles of CuSO₄ / 4.25 L.

Answer:

The answer to your question is 34 g of H₂O₂    

Explanation:

Data

mass of H₂O₂ = ?

mass of O₂ = 32 g

Process

1.- Write the balanced chemical reaction

                   H₂O₂  ⇒   H₂  +  O₂

2.- Calculate the molar mass of H₂O₂ and O₂

Molar mass H₂O₂ = (1 x 2) + (16 x 2) = 34 g

Molar mass of O₂ = 2 x 16 = 32 g

3.- Use proportions to calculate the mass of O₂

                    34g of H₂O₂ -------------- 32g of O₂

                     x                   -------------- 32g of O₂

                          x = (32 x 34) / 32

                          x = 34 g of H₂O₂                                

Answer:

[tex]\boxed{\text{4 m $\cdot$ s$^{-2}$}}[/tex]

Explanation:

F = ma

[tex]a = \dfrac{F}{m} = \dfrac{\text{20 N}}{\text{5 kg}} \times \dfrac{\text{1 kg$\cdot$ m $\cdot$ s$^{-2}$}}{\text{1 N}} = \text{4 m $\cdot$ s$^{-2}$}\\\\\text{The acceleration of the object is } \boxed{\textbf{4 m $\cdot$ s$^{\mathbf{-2}}$}}[/tex]

Answer:

waxing crescent phase

Answer:

Waxing crescent

Explanation:

because i got the question right

Answer:

decrease

Explanation:

If the surface area of a substance increases, the rate of dissolving will increase due to more frequent and effective collisions between the solvent molecules and solute particles.

This effect happens because dissolution is a surface phenomenon, where solvent molecules must collide with the outer surface of the solute. More surface area means more opportunities for these collisions. For instance, powdered CaCO₃ will react faster with HCI than a lump of CaCO₃ because the increased surface area allows more particles to be in contact with the acid, leading to more frequent collisions. Furthermore, an effervescent tablet will dissolve more rapidly when broken into smaller pieces since the available surface area for reaction is increased.

Additionally, the rate of dissolution is influenced by factors such as agitation and temperature. Stirring or shaking a solution can facilitate solute particles contact with solvent, thus increasing dissolution rate. Similarly, dissolving a substance in a warmer solvent can lead to faster dissolution due to increased molecule's kinetic energy.

Answer:Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic. exothermicA description of a chemical reaction that releases heat energy to its surroundings.

Answer:

a

Explanation:

The reaction in question is a combustion reaction involving butane and oxygen, producing carbon dioxide and water; it is not a double replacement reaction.

The equation 2 C4H10 + 13 O2 → 8 CO2 + 10 H2O represents a combustion reaction, not a double replacement reaction. In a double replacement reaction, two compounds exchange parts to form two new compounds. However, in the given reaction, butane (C4H10) reacts with oxygen (O2) in a combustion process to produce carbon dioxide (CO2) and water (H2O), which is typical for hydrocarbons burning in an oxygen-rich environment.

For example, a double replacement reaction is demonstrated by the equation Ca(NO3)2 + KBr → CaBr2 + 2 KNO3, where the cations Ca^2+ and K+ switch places between the anions NO3^- and Br^-, forming two new compounds: calcium bromide and potassium nitrate.

Answer:

Halogens are better oxidizing agents than their alkali metal counterparts within the same period

Halogens have a higher first ionization energy than their alkali metal counterparts within the same period.

Halogens have a higher electron affinity than their alkali metal counterparts within the same period.

Halogens have a higher effective nuclear charge than their alkali metal counterparts within the same period

Explanation:

Effective nuclear charge increases across a period and accounts for increase in ionization energy across a period. This explains why halogens in the same period with alkali metals have higher effective bucket charge as well as ionization energy than the alkali metals.

Similarly, electron affinity increased across a period, halogens have greater ekctron affinity than corresponding alkali metals in the same period.

Answer:49.3

Explanation:4.1j/g c * 25g * (t2-45c)=455j

T2-45c = 455j/4.1j/g c * 25g

455/104.6

45+4.3= 49.3 celsius

The final temperature of water if 455 J of heat is transferred to 25.0g of water at 45.0 degrees Celsius is 63.2°C.

The final temperature of water can be calculated using the following formula:

Q = m × c × ∆T

Where;

According to this question, 455 J of heat is transferred to 25.0g of water at 45.0 degrees Celsius.

455 = 25 × (T - 45)

455 = 25T - 1125

25T = 1580

T = 63.2°C

Therefore, the final temperature of water if 455 J of heat is transferred to 25.0g of water at 45.0 degrees Celsius is 63.2°C.

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