f the k a of an acid is 1.38 × 10 –7 , what is the p k a? 6.86 1.38 8.68 10.7 7.14

Polyurethane foam (C₂7H₃6N₂O₁₀) is a molecular component that might be utilized in a wall-filling material. As a result, choice (1) is right.

A polymer made of numerous organic units connected by urethane molecules is called polyurethane. Most thermosetting polymers of polyurethane do not melt when heated. Thermoplastic in nature, polyurethanes may be heated, melted, and reshaped.

Due to the polymerization of two different types of monomers, polyurethanes are thought of as alternating copolymers. Each molecule of the polyols and isocyanates, which are both utilized as monomers for polyurethanes, typically has two functional groups.

The end product will be soft and elastic if the polyol chain is long and flexible. The final polyurethane product may be hard and robust if the amount of cross-linking is quite high. Since polyurethane does not melt or soften when heated, this structure may contain characteristics of the thermosetting nature of the polymer.

The usage of polyurethane is to create foams, which are then utilized in a variety of products including textiles, furniture, and refrigerator sheets.

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Answer:

the main aim of balance in an equation is making show that the total number of substances on the reactant side is equal to the total number of substances on the product side

Explanation:

so if we were to balance the equation of water water is a compound containing two molecules of hydrogen and one molecule of oxygen therefore

H+O=H2O

\(H+O_2= H_2O\)

Element | Reactant | Product

H | 1 × 4 | 2×2

O | 2 | 1 × 2

\(4H+O_2= 2H_2O\)

Explanation:

2HCl+2Zn----> 2ZnCl+H2

Explanation:

HCL + Zn= zncl2 + H2

plz mark my answer as brainlist if you find it useful.

The number of mole will be 65.81 mole.

An ideal gas would be one for which both the overall volume of the molecules and even the forces that exist between them are so negligible as to have no influence on the behavior of something like the gas.

Number of ideal gas can be calculated by using the formula:

PV = nRT

where, p is pressure, n is number of mole, R is gas constant and T is temperature.

Given data:

V= 1750 \(dm^{3}\) = 1750 L

P = 125,000 p = 1.2 atm

R = 0.082 L /mole kelvin

T = 273+127 = 400 K

Now, put the value of given data in above equation.

1.23atm x 1750L = n x 0.0820atm x Liter/ mole x kelvin  x 400K

n = 65.81 mole.

Therefore, the number of mole will be 65.81 mole

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The given statement is false . Halley's comet takes 5 years to complete an orbit.

A comet that shines especially brightly is a superb comet. Big comets typically arrive once every ten years, at random, erratic periods.

This translates to a circumference of the solar orbit of around 7.6 billion miles. The gravitational pull of the planets causes the period to change from appearance to appearance.

Because Halley was the first comet to show astronomers that comets might return to our night skies repeatedly, it is frequently referred to as the most famous comet. The comet's appearances have now been connected by astronomers to observations made more than 2,000 years ago.

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The complete question is

Halley's comet takes 5 years to complete an orbit. true or false.

The mole fraction of acetone in this solution is 0.31 to 2 significant digits. The mole fraction of a solute in a solution can be calculated as the number of moles of the solute divided by the total number of moles of both solute and solvent in the solution.

First, we need to calculate the number of moles of acetone and methanol:

moles of acetone = 90 g / (58.08 g/mol) = 1.54 mol

moles of methanol = 108 g / (32.04 g/mol) = 3.36 mol

Next, we add up the moles of both solute and solvent:

total moles = 1.54 mol + 3.36 mol = 4.90 mol

Finally, we can calculate the mole fraction of acetone as follows:

mole fraction of acetone = (1.54 mol of acetone) / (4.90 mol) = 0.31

So the mole fraction of acetone in this solution is 0.31 to 2 significant digits.

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Complete question:

A solution is made by mixing 90. g of acetone ((CH₃)₂CO) and 108. g of methanol (CH₃OH). Calculate the mole fraction of acetone in this solution. Round your answer to 2 significant digits. X?

The mass of the platinum metal is approximately 195 grams.

The mass of the platinum metal can be calculated using the formula:

mass = density x volume

Substituting the given values, we get:

mass = 24.9 g/cm3 x 7.85 cm3

mass = 195.465 g

Rounding this answer to the nearest gram, we get:

mass ≈ 195 g

Therefore, the mass of the platinum metal is approximately 195 grams.

It's important to note that density is a physical property of matter that describes the relationship between the mass of an object and its volume. In this case, the density of platinum is quite high, which is why it's often used in applications that require a high degree of durability and resistance to wear and tear.

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The molar composition of the stack gas on a dry basis and the mole ratio of water to dry stack gas is 0.1143.

the equation is,

C2H6 + 7/202 → 2CO2 + 3H2O

1mol      3.5mol    2mol      3mol

for 100 mol GHG, & required = 100×3.5 mol

                           O2 required = 350 mol

                                    O₂ fed = 1.5×350 mol

                                    O₂ fed =525 mol

N2 fed = 0.79/0.21 X 525 mol

N2 fed =1975mol

Mole ratio of water to dry stack gas = Moles of water/Moles of dry stack

                                                                                          gas Without water                                  

                                                            =270 mol / 2362.5 mol

                                                            = 0.1143

Mole ratio water to of dry stack gas = 0.1143

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The reaction between pottasium metal and chlorine gas is an example of combination reaction and the balanced equation is as follows: 2K + Cl₂ → 2KCl

A chemical equation is a symbolic representation of a chemical reaction where reactants are represented on the left, and products on the right.

A chemical equation is said to be balanced when the number of atoms of each element on both sides of the equation are the same.

According to this question, potassium metal reacts with chlorine gas to form solid potassium chloride. The balanced equation is as follows:

2K + Cl₂ → 2KCl

Based on the above equation, pottasium combines with chlorine chemically to form pottasium chloride compound, hence, it is an example of combination reaction.

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Fluorescence involves the emission of light by molecules due to electronic transitions and intermolecular interactions.

Fluorescence is a phenomenon observed in certain molecules where they absorb light energy and re-emit it at a longer wavelength. In the context of quantum mechanics, fluorescence involves electronic transitions between energy levels within the molecule.

When a molecule absorbs a photon, it promotes an electron to a higher energy state. The excited electron then undergoes a non-radiative relaxation process, releasing excess energy as heat.

However, in fluorescence, the excited electron returns to the ground state via a radiative transition, emitting a photon with lower energy (longer wavelength) than the absorbed photon.

This emission of light is facilitated by intermolecular interactions, such as dipole-dipole interactions or energy transfer processes. Overall, fluorescence is a result of the quantum mechanical behavior of electrons and the interactions between molecules.

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To analyze the world around us on a daily basis, it means we must keep a record of data of the phenomena that we wish to observe. In doing so we are able to track any changes and make informed judgments in relation to same.

One can decide to keep track of the rate of change of forest size on a global scale. Thanks to satellites and other research institutions, this is now possible.

One can also decide to keep track of health-related data on a global scale.

Other factors are:

It is to be noted that World System Analysis emphasizes world-systems rather than nation-states, the importance of considering historical processes as they unfold over long periods of time, and the integration of bodies of knowledge that are typically viewed as distinct from one another, such as history, political science, economics, and sociology, within a single analytical framework.

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The speed of the race car in kilometers per minute is approximately 2.66 km/min.

To convert miles per hour to kilometers per hour, we can use the conversion factor;

1 mile = 1.61 kilometers

So, multiplying both sides by 1.61 gives;

1 mile/hour = 1.61 kilometers/hour

Therefore, we can convert 99 miles/hour to kilometers/hour as follows:

99 miles/hour × 1.61 kilometers/mile = 159.39 kilometers/hour

So, the speed of the race car in kilometers per hour is 159.39 km/h.

To convert kilometers per hour to kilometers per minute, we can use the fact that there are 60 minutes in an hour. So;

159.39 kilometers/hour ÷ 60 minutes/hour

= 2.66 kilometers/minute

Therefore, the speed of the car is 2.66 km/min.

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The element that we can be able to use for the experiment in place of potassium is sodium.

We know that the elements that can be found in the same group does react in the same way. Now we know that we have to look about among the options so that we would be able to know element that is in the same group as potassium.

Given that both sodium and potassium are members of group 1, we have to look out for the element that element thus we have to select sodium.

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The mass of potassium chloride produced when potassium chlorate decomposes in this instance is 178.92 g.

The balanced chemical equation is:

2KClO3(s) → 2KCl(s) + 3O2(g)

From the equation, we can see that 2 moles of KClO3 produce 2 moles of KCl. Therefore, 1 mole of KClO3 produces 1 mole of KCl.

Given that 2.4 moles of KClO3 decompose, the amount of KCl produced will also be 2.4 moles.

Now, we need to find the mass of KCl produced, using the molar mass of KCl:

KCl: K = 39.10 g/mol, Cl = 35.45 g/mol

Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol

Mass of KCl produced = number of moles x molar mass

Mass of KCl produced = 2.4 moles x 74.55 g/mol = 178.92 g

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At 1 atm, the amount of  energy is required to heat 79.0 g \(H_2O_{(s)\) at −22.0° C to \(H_2O_{(g)\) at 139.0° C is 228.66 kJ.

To calculate the energy required to heat water from -22.0 °C to 139.0 °C, we need to consider two steps:

Heating the solid water (ice) from -22.0 °C to 0 °C.

Heating the liquid water from 0 °C to 139.0 °C and then vaporizing it to steam.

First, let's calculate the energy required to heat the solid water:

q1 = m * \(C_{solid\) * ΔT1

where

m = mass of water = 79.0 g

\(C_{solid\) = specific heat capacity of ice = 2.09 J/g°C (from the provided table)

ΔT1 = change in temperature = 0 °C - (-22.0 °C) = 22.0 °C

q1 = 79.0 g * 2.09 J/g°C * 22.0 °C

q1 = 3665.24 J

Next, let's calculate the energy required to heat the liquid water and vaporize it:

q2 = m * \(C_{liquid\)* ΔT2 + m * Δ\(H_{vaporization\)

where

\(C_{liquid\)= specific heat capacity of liquid water = 4.18 J/g°C (from the provided table)

ΔT2 = change in temperature = 139.0 °C - 0 °C = 139.0 °C

Δ\(H_{vaporization\) = enthalpy of vaporization of water = 40.7 kJ/mol = 40.7 kJ/18.015 g (from the provided table)

q2 = 79.0 g * 4.18 J/g°C * 139.0 °C + 79.0 g * (40.7 kJ/18.015 g)

q2 = 45130.86 J + 178.86 kJ

q2 = 224991.86 J

Now, we can calculate the total energy required:

q = q1 + q2

q = 3665.24 J + 224991.86 J

q ≈ 228657.10 J

Therefore, approximately 228,657.10 J (or 228.66 kJ) of energy is required to heat 79.0 g of solid water at -22.0 °C to water vapor at 139.0 °C at 1 atm.

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Answer:

14.9 g Sb

Explanation:

The mass of Sb produced can be calculated using the conversion:

Molar Mass (g/mol) = mass (g) / moles

Antimony (Sb) has the molar mass 121.76 g/mol. This value is found on the periodic table. You have been given the moles produced. Therefore, you can find the mass of Sb by plugging these values into the formula and simplifying.

Molar Mass = mass / moles

121.76 g/mol = mass / 0.122 moles

14.9 = mass

Answer:

because space is near-perfect vacuum - meaning it has exceedingly few particles- there is virtually nothing in the space between stars and planets to scatter light to our eyes

Answer:

1. D 2.. A 3. C 4. B

Explanation:

just took the quiz

We can classify each rock as intrusive or extrusive and basaltic or granitic as follows; Rock A - Extrusive, Basaltic, Rock B - Intrusive, Granitic, Rock C - Extrusive, Basaltic, and Rock D - Extrusive, Basaltic.

Rock A - Extrusive, Basaltic

Rock A is described as having dark-colored large grains, which indicates a fine-grained texture, typical of extrusive rocks. The presence of dark-colored large grains suggests a basaltic composition.

Rock B - Intrusive, Granitic

Rock B is described as having large crystals and a high percentage of silica, which suggests a coarse-grained texture, typical of intrusive rocks. The high silica content and large crystals indicate a granitic composition.

Rock C - Extrusive, Basaltic

Rock C is described as having a fine-grained texture and being light-colored, which are characteristic features of extrusive rocks. The fine-grained texture suggests a rapid cooling, typical of extrusive rocks, and the light color is indicative of a basaltic composition.

Rock D - Extrusive, Basaltic

Rock D is described as being from the Hawaiian volcano area and having no visible crystals. This indicates a glassy texture, typical of rapidly cooled extrusive rocks. The origin from a volcanic area and glassy texture suggest a basaltic composition.

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Answer:

it is C. take it to the local automotive parts store to be recycled

Explanation:

hope this helped have a nice day!

Answer:

exposure to radiation i think

Explanation:

Answer:

KNO3 (Potassium Nitrate)

Explanation:

I just know.

Solids, liquids, and gases differ in terms of packaging of the atoms in its constituent atomic level.

Solids, liquids, and gases are the three main states of matter. They differ in the way their atoms or molecules are arranged and how they interact with one another. Solids have a definite shape and a definite volume. The atoms or molecules in a solid are tightly packed together and are not free to move around. Solids also have a low compressibility and a high density. Liquids have a definite volume but no definite shape. They take the shape of their container. The atoms or molecules in a liquid are close together but are free to move around. Liquids have a low compressibility and a lower density than solids. Gases have no definite shape or volume. They expand to fill their container. The atoms or molecules in a gas are widely spaced and are free to move around. Gases have a high compressibility and a low density. Examples of gases include air, oxygen, and natural gas. In summary, Solids have a fixed shape and volume, liquids take the shape of their container, have a definite volume and gases have no fixed shape or volume and expand to fill their container.

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We are asked to convert 1 quart from grams/liters to pounds/grams. Given that 1 gallon is equal to 4 quarts, we can start by determining the equivalent value of 1 gallon.

To do this, we multiply 4 quarts by the conversion factor of 946.27 grams/liter as follows:  

1 gallon = 4 quarts

1 gallon = 4 x 946.27 g/l

1 gallon = 3,784.08 g/l

Next, we can convert this value from grams/liter to pounds/grams. To do this, we need to use the conversion factor of 0.00220462 pounds/gram.

Therefore: 1 gallon = 3,784.08 g/l

1 gallon = 3,784.08 x 0.00220462 lbs/g

1 gallon = 8.3454 lbs

Therefore, 1 gallon is equal to 8.3454 pounds.

Now, we can determine the equivalent value of 1 quart by dividing 1 gallon by 4.1 quart = 1/4 gallon1 quart

= 1/4 x 8.3454 lbs

1 quart = 2.08635 lbs

Finally, we can convert this value from pounds to grams using the conversion factor of 453.592 grams/pound.

1 quart = 2.08635 lbs

1 quart = 2.08635 x 453.592 g/l

1 quart = 944.19 g

Therefore, 1 quart is equal to 944.19 grams.

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Answer:

A pure substance consists only of one element or one compound and a mixture consists of two or more different substances, not chemically joined together.

So, a mixture is like mixing - let's say - sugar and rice together (dry BTW), but you can clearly see both substance are not chemically mixed together, if that makes sense. Thus, you can easily separate them out.

The hazardous substance in automobile exhaust that is also present in high concentration in tobacco smoke is acrolein.

Substance that tobacco smoke and the exhaust of automobiles contains a has it is substance called acrolein in very very high concentration.

Inhaling acrolein can give rise to several breathing problems like shortness in breathing and also irritation in lungs.

Acrolein is formed when the fats are overheated apart from automobiles and tobacco a very low amount of acrolein is also found in over used cooking oil.

To reduce acrolein from the automobile exhaust lead based adsorption substances are preferred to be used in automobile exhaust.

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The ΔHvap of ethyl acetate in the given conditions is 35.08 kJ/mol.

Enthalpy of vaporization:

To find the ΔHvap (enthalpy of vaporization) of ethyl acetate in kJ/mol, you can use the Clausius-Clapeyron equation, which is:

ln(P1/P2) = (ΔHvap/R) * (1/T2 - 1/T1)

Given:
Normal boiling point (T2) = 77°C = 350.15 K (converting to Kelvin by adding 273.15)
Vapor pressure at 20°C (P1) = 73 Torr
Temperature at P1 (T1) = 20°C = 293.15 K (converting to Kelvin)
P2 = 760 Torr (normal atmospheric pressure at boiling point)
R = 8.314 J/(mol*K) (universal gas constant)

First, plug the values into the equation:

ln(73/760) = (ΔHvap/8.314) * (1/350.15 - 1/293.15)

Now, solve for ΔHvap:

ΔHvap = 8.314 * (ln(73/760) / (1/350.15 - 1/293.15))

ΔHvap ≈ 35079 J/mol (rounded to the nearest whole number)

Finally, convert ΔHvap to kJ/mol:

ΔHvap ≈ 35.08 kJ/mol (rounded to two decimal places)

So, the ΔHvap of ethyl acetate is approximately 35.08 kJ/mol.

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Answer:

MRCORRECT has answered the question

Explanation:

13 electrons

So... for the element of ALUMINUM, you already know that the atomic number tells you the number of electrons. That means there are 13 electrons in a aluminum atom. you can see there are two electrons in shell one, eight in shell two, and three in shell three.

7 electrons

So... for the element of NITROGEN, you already know that the atomic number tells you the number of electrons. That means there are 7 electrons in a nitrogen atom. Looking at the picture, you can see there are two electrons in shell one and five in shell two.

Molar mass, which is measured in grammes per mole units, is the mass of one mole of a substance. The unknown compound's molar mass is 226.2 g/mol plus the molar masses of any additional elements it may contain.

We can first calculate the mass of the oxygen in one mole of the chemical to obtain the molar mass of the unknown compound: The chemical has 35.53 g of oxygen per mole. Oxygen has an atomic mass of 16.00 g/mol. As a result, there are 2.2206 moles of oxygen in a mole of the molecule, or 35.53 g / 16.00 g/mol. As there are 4 atoms per molecule, the following formula can be used to determine the molar mass of the unknown compound: Molar mass = (35.53 g + molar mass of other elements) / 2.2206 mol * 4 atoms/molecule. Molar mass = (35.53 g / 2.2206 mol * 4) + molar mass of other elements is the result of solving for the molar mass of the unidentified substance. Molar mass is equal to 226.2 g/mol plus the molar mass of other elements. Therefore, The unknown compound's molar mass is 226.2 g/mol plus the molar masses of any additional elements it may contain.

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Answer:

I think it's D, cicada.

According to Oxford, a Hemipteran is "an insect of the order Hemiptera, such as an aphid, cicada, or leafhopper."

Hope this helps! I also hope it's not wrong, but I do not think it is.

Also please let me know if this is correct.

Answer:

B

Explanation:

The answer is sunlight solar cells directly convert the sunlight into electricity

Answer:

B

Explanation:

Sunlight, or solar energy is the type of energy which is not used by a turbine to generate electricity.