the amino acid serine has a backbone made out of amino group and a carboxyl group. its r group has a hydroxyl group. which of the following better represents the structure of this amino acid at neutral ph?

Answer:

No.

Explanation:

All the elements have the different number of protons .

Answer:

no it is not true because atoms may have the same number of neutrons but they never have the same number of protons

Explanation:

Answer: B

Explanation:

''Muscle tissue is composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts''

The ph of the solution after the addition of 200.0 ml of HNO3 is 3.259.

The steps to calculate the pH of the solution after addition of 200 mL of HNO3 are :

Step 1. Calculate the moles of NH3 and HNO3 in the solution.

Moles of NH3 = (Volume of NH3 solution)(Concentration of NH3 solution) = (100.0 mL)(0.10 M) = 0.01 mol

Moles of HNO3 = (Volume of HNO3 solution)(Concentration of HNO3 solution) = (200.0 mL)(0.10 M) = 0.02 mmol

The limiting reagent is the one with fewer moles. In this case, NH3 is the limiting reagent since it has 0.010 mol, which is less than the 0.020 mol of HNO3.

Step 2. Now, we need to determine the excess moles of HNO3.

Excess moles of HNO3 = Moles of HNO3 - Moles of NH3 = 0.02 mol - 0.01mol = 0.01 mol

Step 3. Finally, we can calculate the pH of the solution by using the Henderson-Hasselbalch equation.

pH = pKa + log([A-]/[HA])

where pKa = -log(Kb) = -log(1.8 × 10-5) = 4.74

[A-] = Concentration of the conjugate base (NH4+) ; [HA] = Concentration of the weak acid (NH3)

pH = 4.74 + log([NH4+]/[NH3])

Since, NH3 is the limiting reagent, we can assume that all of the NH3 has been converted to NH4+.

pH = 4.74 + log([NH4+]/0) = 4.74 + log([NH4+])

Step 4. The concentration of NH4+ can be calculated from the excess moles of HNO3 and the volume of the solution.

[NH4+] = (Excess moles of HNO3)/(Volume of solution) = (0.01 mol)/(300.0 mL) = 0.033 M

Plugging this value into the Henderson-Hasselbalch equation, we get the following pH.

pH = 4.74 + log(0.033)

pH = 3.259

Therefore, the pH of the solution after the addition of 200.0 mL of HNO3 is 3.259

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Answer:

valeric acid

Explanation:

I don't know exactly. But try this one.

Answer:

IUPAC NAME: PENTANOIC ACID

COMMON NAME: VALERIC ACID

BH3 acts as a Lewis acid in this reaction represented by BH3 + H- --> BH4 -.

BH3 acts as which acid ?

BH3 acts as a Lewis acid in this reaction represented by BH3 + H- --> BH4 -.What is a Lewis acid?A Lewis acid is defined as an electron acceptor since it accepts a pair of electrons from a Lewis base to form a coordination complex. A Lewis acid is usually classified as an electron-pair acceptor.Arrhenius acidAn Arrhenius acid is defined as a substance that increases the hydrogen ion concentration (H+) in water when dissolved. Arrhenius acid has specific chemical characteristics that distinguish it from other types of acids.Brønsted-Lowry acidA Brønsted-Lowry acid is a proton donor. It is a substance that gives hydrogen ions, H+, to another substance. The Brønsted-Lowry acid is a more general concept than the Arrhenius acid.Lewis acidA Lewis acid is an electron pair acceptor. It is a substance that accepts a pair of electrons from another substance in order to form a chemical bond.

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Answer:-Fill an oversized 1L graduated cylinder with a set amount 500ml of water and record below. To find the total Volume displaced, subtract Initial Volume and Volume of Object. To calculate Density divide the Mass in grams by the Volume displaced in milliliters. Finally record whether the object floats or sinks.

Measure the volume of water poured into a graduated cylinder, then place the object in the water and remeasure the volume. The difference between the two volume measurements is the volume of the object. Now simply divide the mass by the volume to calculate the density of the object.

Using a mass balance, mass the container. Pour the liquid into the container and mass them together. Subtract the mass of the container from the mass of the container with the liquid. The difference will be the mass of the liquid alone.

The equation for Beer's law is a straight line with the general form of y = mx +b. where the slope, m, is equal to εl. In this case, use the absorbance found for your unknown, along with the slope of your best fit line, to determine c, the concentration of the unknown solution.

Answer:

its height relative to some reference point, its mass, and the strength of the gravitational field

Explanation:

Gravitational energy is the potential energy associated with gravitational force, such as elevating objects against the Earth’s gravity. The potential energy due to elevated positions is called gravitational potential energy.

The factors that affect an object’s gravitational potential energy are the following; its height relative to some reference point, its mass, and the strength of the gravitational field it is in. For instance, consider a wallet lying on a table, it has less gravitational potential energy than the same wallet lying on top of a taller cupboard, and yet lesser gravitational potential energy than a heavier wallet lying on the same table.

If an object lies at a certain height above the Moon’s surface, it has less gravitational potential energy than the same object lying at the same height above the Earth’s surface because the Moon’s gravitational force is weaker.

Answer:

18,9g de hexano son necesarios

Explanation:

Basados en la ley de Raoult, la presión de vapor ejercida por una solución es:

P = P°*Xsolvente

Donde P es la presión de la solución deseada = 700mmHg, P° la presión de vapor de vapor del benceno = 1atm = 760mmHg y X es la fracción molar del solvente (Benceno).

Reemplazando:

700mm Hg = 760mmHg * X(Benceno)

0.9211 = X(Benceno)

La fracción molar de benceno se define como:

X = Moles benceno / Moles benceno + Moles hexano

Moles benceno -Masa molar: 78g/mol-

200g * (1mol/78g) = 2.5641 moles benceno

X = Moles benceno / Moles benceno + Moles hexano

0.9211 = 2.5641 moles benceno / 2.5641 moles benceno + Moles hexano

0.9211moles Hexano + 2.3618 = 2.5641

0.9211*Moles Hexano = 0.2023

Moles hexano = 0.2023/0.9211 = 0.2196 moles hexano.

Masa Hexano -Masa molar: 86g/mol-

0.2196 moles hexano * (86g/mol) =

La cantidad de hexano (C6H14) que se debe agregar a 200 g de benceno para permitir que la presión de vapor se convierta en 700 mm de Hg sería:

18.9 g

Usando la ley de Raoult, la presión de vapor que libera una solución se encuentra por:

P = P ° × X disolvente  

Donde (P) denota la presión de la solución deseada

P ° denota la presión de vapor del benceno y

X denota la fracción molar del disolvente (benceno).

En el caso dado,

(P) = 700 mmHg,

P° = 1atm = 760mmHg

Fracción molar de benceno = 0,9211           (∵ 700/760)

La fracción molar de benceno (X)  = Moles de benceno/Moles de benceno + Moles de hexano

Moles de benceno - Masa molar: 78g / mol -  200 g × (1 mol / 78 g)

= 2.5641 moles de benceno

X = Moles de benceno/Moles de benceno + Moles de hexano

0.9211 = 2.5641 moles Benceno/2.5641 moles Benceno + Moles de Hexano

⇒ 0,9211 × moles de Hexano + 2,3618 = 2,5641    

⇒ 0.9211 × moles de Hexano = 0.2023

∵ Moles de Hexano = 0.2023/0.9211

\(= 0.2196 moles\)

\(Hexane mass - Molar mass = 86g/mol - 0.2196 mole hexane\) × \((86g/mole)\)

\(= 18.9g\)

Por tanto, 18,9 g es la respuesta correcta.

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The refrigerator would use 180 kilowatt-hours (kWh) of electric energy over the course of 30 days, assuming it runs for 12 hours each day.

To calculate the kilowatt-hours (kWh) of electric energy used by the refrigerator in 30 days, we need to multiply the power rating by the total running time.

Given:

Power rating of the refrigerator = 500 W

Running time per day = 12 hours

Number of days = 30

First, we need to convert the power rating from watts to kilowatts:

Power rating = 500 W / 1000 = 0.5 kW

Next, we calculate the total energy used in kilowatt-hours (kWh) over the 30-day period:

Energy used = Power rating × Running time × Number of days

Energy used = 0.5 kW × 12 hours/day × 30 days

Energy used = 180 kWh

Therefore, the refrigerator would use 180 kilowatt-hours (kWh) of electric energy over the course of 30 days, assuming it runs for 12 hours each day.

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Answer:

The answer is "Ammonium nitrate is the reactant of this chemical reaction".

Explanation:

The Ammonium nitrate (NH4NO3)  is an ammonium and nitrate ionic crystalline solid. In water and hygroscopic as a strong, it's also highly soluble, although it does not form hydrates.

It uses as a nutrient for generating medications as well as leaven fertilizers and explosive materials. Nitrate in ammonium is sodium bicarbonate ammonium chloride. It is incendiary, an oxidizing agent, and a fertilizer.

The disproportionation reaction of the radicals produced by the most energetically favored homolytic bond cleavage in the molecule CH3-CH2-CH-CH2-CH3 would form the alkane-alkene pair CH4 and (CH3)2C=C(CH3)2.                                  

The most energetically favored homolytic bond cleavage in the given molecule would be the one between the two carbon atoms in the middle of the chain, resulting in two radicals - one with a methyl group and the other with a propyl group. To form an alkene, these radicals need to combine in a way that would lead to the formation of a double bond. Among the given options, only option C has two radicals that can combine to form a double bond between the second and third carbon atoms, resulting in the alkene CH2=CH-CH=CH-CH3. Therefore, the answer is (C) CH3CH2CH2 and CH2=C(CH3)CH=CH2.
The primary carbon radical formed after cleavage will react with a secondary carbon radical, leading to the formation of methane (CH4) and the alkene, 2,3-dimethyl-2-butene [(CH3)2C=C(CH3)2].

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The interaction strength of mixed states is stronger when the solubility of substance 'a' in substance 'b' does not change with temperature. So, option(d) is right one.

According to Le Chatelier's principle is used to predict the effect of a change in conditions on chemical equilibrium. This principle states that when any system is at equilibrium and if we change in concentration, temperature, or pressure, the system changes to a new equilibrium to cancel the change. In the given solvation process as the temperature increases the solubility decreases.

According to Le Chatelier's principle, we can say that the solvation process is an exothermic process. The solvation process will be exothermic if the interactions in the unmixed state are weaker than the interactions in the mixed state. In the mixed state strong bonds are formed, thus the heat will be released and the process will be exothermic.

Hence, Interactions are strogner in the mixed state.

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Complete question:

if the solubility of substance a in substance b does not change when temperature increases, what can you conclude about the relative interaction strengths in the mixed (M) and unmixed (UM) states? Unmixed state interactions: A---A and B B Mixed state interactions:

A --- B

a) Mixed and unmixed state have equally strong interactions

b)More information is necessary to decide c)Interactions are stronger in the unmixed state

d) Interactions are stronger in the mixed state

Empirical formula mass

Molecular fornula mass:-180g/mol

Molecular formula:-

Answer:

its bar graph

Explanation:

Answer:

overflow the top edge of the filter paper

The Executive Office of the President is a set of permanent agencies and is responsible for checking presidential power. lobbying the president on behalf of interest groups. performing defined management tasks for the president. deciding which bills the president will veto. The statement is incorrect.

The Executive Office of the President (EOP) is not responsible for checking presidential power, lobbying the president on behalf of interest groups, or deciding which bills the president will veto.  The EOP is a group of permanent agencies and offices that provide administrative support and policy advice to the president. Its primary function is to assist the president in carrying out their duties and responsibilities effectively. The EOP includes agencies such as the Office of Management and Budget (OMB), the National Security Council (NSC), the Council of Economic Advisers (CEA), and the Office of the United States Trade Representative (USTR), among others. While the EOP plays a crucial role in supporting the president, checking presidential power is primarily the responsibility of the other branches of government, such as Congress and the judiciary. Lobbying the president on behalf of interest groups is typically conducted by external organizations, such as advocacy groups or lobbyists. The decision of which bills the president will veto is ultimately up to the president themselves, guided by their administration's policy priorities and advice from various advisors.

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The mass of HNO3 obtained is 12.46 g from the given reaction.

The chemical reaction is :

Potassium Nitrate + Sulphuric acid ------> Potassium Bisulphate + Nitric acid.

The above reaction is basically used for the making of nitric acid.

Less than 200 degree celcius the Nitric acid if more than 200 degree celcius then it will form Potassium Sulphate.

Now,

1 mol of KNO3 reacts with1 mol of concentrated H2SO4 to give 1 mol HNO3

Molar Mass of KNO3 = 101.1 g

Molar mass of H2SO4 = 98.07 g

Mass of H2SO4 that can react with 20 g of KNO3 = (20 g* 98.07 g )/ 101.1 g

= 19.4 g

Molar mass of nitric acid= 63.01 g

Hence mass of nitric acid  produced by 20 g of KNO3 = (20 g * 63.01 g ) / 101.1 g = 12.46 g

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Formula

\(\ell=\frac{n h}{2 \pi}\)

\(\ell = angular \: momentum\)

\(n = principal quantum number \\ h = Planck's constant \\ \pi = pi\)

When working with strong acids and bases, it is important to take certain precautions to ensure your safety. The correct answer to this question is d) Always wear goggles and gloves.

Acids and bases can be very corrosive and can cause damage to your skin and eyes. Wearing goggles and gloves can help protect you from any accidental spills or splashes. It is also important to only perform work in the fume hood (option b) to ensure that any harmful fumes are properly ventilated. It is not necessary to keep a Bunsen burner switched on nearby (option a) or to only use plastic lab equipment (option c) when working with acids and bases.

In summary, when working with strong acids and bases, it is important to always wear goggles and gloves, and to perform work in the fume hood. These precautions can help protect you from any potential harm.

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According to the information of the graph we can infer that if the water were cooled to 5°C the reaction time would be close to 30 seconds.

To establish what would the reaction time be if the water were cooled to 5°C we have to analyze the information of the graph specially the trend. In this case, we have to take into account where are located the point that relate time and temperature.

In this case, the trend is more time with less temperature. So if the water were colled to 5°C, the time would be close to 30 seconds.

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Answer: The new temperature is \(63^{o}C\).

Explanation:

Given: \(V_{1}\) = 1.90 L,    \(T_{1} = 21.0^{o}C\)

\(V_{2}\) = 5.70 L,         \(T_{2} = ?\\\)

Formula used to calculate new temperature is as follows.

\(\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}\)

Substitute the values into above formula as follows.

\(\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}\\\frac{1.90 L}{21.0^{o}C} = \frac{5.70 L}{T_{2}}\\T_{2} = 63^{o}C\)

Thus, we can conclude that the new temperature is \(63^{o}C\).

Answer: Ka = 5.71x10^-7

Explanation:

Let HA be the weak acidHA ==> H^+ + A^-

Ka = [H+][A-]/[HA]

Since pH = 3.25, this means [H+] = 1x10^-3.5 = 3.16x10^-4 = [A-] also.

Ka = (3.16x10^-4)(3.16x10^-4)/0.175

Ka = 5.71x10^-7

The value of Ka for the weak acid is as follows:Ka = [H+][A-] / [HA]⇒Ka = (0.009917)2 / (0.165)⇒Ka = 5.92 × 10^-5

Given information:

pH of weak acid = 3.25pH = - log[H+][H+] = antilog (-pH)= antilog (-3.25)= 5.62 x 10^(-4).

Now, 0.175 M solution of a weak acid is given.

Let’s assume that the acid is represented by the chemical formula HA.[H+] = [A-] = x (Since it is a weak acid, we can assume that it dissociates very little, so the concentration of H+ and A- ions can be taken as x).

Now, the concentration of HA can be assumed to be (0.175 - x)M.

We can apply the formula for the acid dissociation constant (Ka) of weak acids here, i.e., Ka = [H+][A-] / [HA]Ka = x2 / (0.175 - x), Ka = 5.62 × 10^-4.

Therefore, 5.62 × 10^-4 = x2 / (0.175 - x), The value of x is very small compared to 0.175.

Hence we can neglect x in comparison with 0.175.

Therefore,0.175 - x = 0.175∴5.62 × 10^-4 = x2 / (0.175)⇒x2 = 0.175 × 5.62 × 10^-4⇒x2 = 9.835 × 10^-5⇒x = √(9.835 × 10^-5)⇒x = 0.009917 mol/L

Now, [HA] = 0.175 - x = 0.175 - 0.009917 = 0.165 M

Therefore, the value of Ka for the weak acid is as follows: Ka = [H+][A-] / [HA]⇒Ka = (0.009917)2 / (0.165)⇒Ka = 5.92 × 10^-5

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Answer:

See explanation

Explanation:

The major difference between distance and displacement is that distance is a scalar quantity while displacement is a vector quantity. Scalar quantities have magnitude without direction while vector quantities have both magnitude and direction.

The distance covered by Benjamina in both cases just refer to the difference in her position at each time without reference to the direction in which she changed her position.

Her displacement will clearly mention the direction in which she moved both when she walked to the front door of her apartment and when she walked to a friend's apartment.

Answer:

The state with the lowest possible energy consistent with the state of maximum disorder

so letter A

If a system is left to change spontaneously then, the state with the lowest possible energy is consistent with the state of maximum disorder. option A is correct.

A spontaneous change may be so fast or rapid or in a fraction of time that it is essentially instantaneous or fast or so slow that it cannot be observed over any practical time of  period.

A is the spontaneous change is one in which the system happening into which the  A an increase or boost  in internal energy B lowering  decline in entropy C lowering in energy D no energy change Medium.

The time-evolution  or change of a system in which it releases free energy and it moves to a lower, or decreased more thermodynamically stable energy state, closer to  attend the thermodynamic equilibrium.

Therefore, the system is left to change spontaneously then, and the state with the lowest possible energy is consistent with the state of maximum disorder. option A is correct.

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Answer:

On bullets, the class characteristics are the rifling specifications of the barrel from which the bullet was fired. ... In a barrel, the individual characteristics are produced by the random imperfections and irregularities of the tool or tools used to produce the lands and grooves, and by use, corrosion, or damage.

Explanation:

Answer:

its 210

Explanation:

Just add all atomic mass used in the formula together: 2*(14+16*3)+88= 2*62+88=124+88=210

Hope this was helpful

The relative formula mass of strontium nitrate Sr(NO₃)₂ is 210

The relative atomic masses of N, O and Sr are 14,16 and 88 respectively.

In calculating the relative atomic mass of an element with isotopes, the relative mass and proportion of each is taken into account. Adding the atomic masses together gives the relative formula mass of a compound

So, relative atomic mass of Sr(NO₃)₂ is calculated as

88+ 2(14+16×3) = 210

The atomic mass constant (symbol: mu) is defined as being 1/12 th of the mass of a carbon-12 atom. Since both quantities in the ratio are masses, the resulting value is dimensionless; hence the value is said to be relative atomic mass.

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option (B) KOH is the correct answer

KOH is the substance that, when added to the solution, is most likely to raise the pH .

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