you dissolve of the aminoacid leucine in a solution with . select the structure of the predominant form of the amino acid in solution?

According to the Arrhenius concept, if HNO3 were dissolved in water, it would act as an acid. This is the correct answer.

This is because HNO3 would donate a proton (H+) to the water, increasing the concentration of H+ ions in the solution. The Arrhenius concept is a definition of acids and bases proposed by Svante Arrhenius in 1884.

According to this concept, an acid is a substance that produces hydrogen ions (H+) when dissolved in water, while a base is a substance that produces hydroxide ions (OH-) when dissolved in water.HNO3 is an example of an acid because it produces H+ ions when dissolved in water.

This can be seen from the following equation:

HNO3 + H2O → H3O+ NO3

In this equation, HNO3 donates an H+ ion to the water molecule, forming H3O+.

Therefore, HNO3 acts as an acid when dissolved in water.

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Explanation:

To solve this problem, we first need to calculate the number of moles of NH3 and HCl using the ideal gas law:

n = PV / RT

where:

P = pressure in atmospheres

V = volume in liters

T = temperature in kelvins

R = 0.08206 L atm/mol K (the ideal gas constant)

For NH3:

n(NH3) = (1.02 atm) (4.21 L) / (0.08206 L atm/mol K) (300 K)

n(NH3) = 0.177 mol

For HCl:

n(HCl) = (0.998 atm) (5.35 L) / (0.08206 L atm/mol K) (299 K)

n(HCl) = 0.204 mol

From the balanced equation, we can see that the stoichiometry of NH3 to HCl is 1:1, so NH3 is the limiting reactant since it has fewer moles. The balanced equation also tells us that the ratio of NH3 to NH4Cl is 1:1, so the number of moles of NH4Cl produced is also 0.177 mol.

To calculate the mass of NH4Cl produced, we need to use the molar mass of NH4Cl:

M(NH4Cl) = 14.01 g/mol (N) + 4(1.01 g/mol) (H) + 35.45 g/mol (Cl)

M(NH4Cl) = 53.49 g/mol

mass(NH4Cl) = n(NH4Cl) × M(NH4Cl)

mass(NH4Cl) = 0.177 mol × 53.49 g/mol

mass(NH4Cl) = 9.48 g

Therefore, the mass of NH4Cl produced is 9.48 g.

To determine the excess reactant, we can calculate how much of each reactant is consumed based on the stoichiometry of the reaction. Since NH3 and HCl react in a 1:1 ratio, we can assume that all of the NH3 is consumed, so we need to calculate the amount of HCl that is consumed:

n(HCl) consumed = n(NH3) = 0.177 mol

n(HCl) initially = (0.998 atm) (5.35 L) / (0.08206 L atm/mol K) (299 K)

n(HCl) initially = 0.204 mol

n(HCl) excess = n(HCl) initially - n(HCl) consumed

n(HCl) excess = 0.204 mol - 0.177 mol

n(HCl) excess = 0.027 mol

To convert this to a volume, we can use the ideal gas law:

V(HCl) excess = n(HCl) excess × RT / P

V(HCl) excess = 0.027 mol × (0.08206 L atm/mol K) (299 K) / (0.998 atm)

V(HCl) excess = 0.686 L

Therefore, the excess reactant is HCl, and the limiting reactant is NH3.

The 2 processes in which the particles will lose or gain energy are:

1) Temperature Change Or

2) State Change

A particle losses or gains energy when its Temperature changes i.e. A vessel filled with boiling water (100 degrees C ) cools down at the room temperature OR

when its State changes i.e. A bucket full of ice is kept at a room temperature (state changes from Solid to Liquid)

It is because of the breaking or formation of bonds, which results in loss or gain in energy.

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The reaction rate can be affected by the state of the reactants, the frequency of collisions between particles, and the average kinetic energy of the particles in the reactant mixture. Option B is correct.

The state of the reactants can affect the reaction rate. For example, a solid reactant will typically react more slowly than a liquid or gaseous reactant because the molecules in a solid are typically held together more tightly and have less opportunity to come into contact with one another.

The more often the reactant molecules collide with each other, the higher the chance of a successful reaction. Therefore, increasing the frequency of collisions between particles can increase the reaction rate. This can be achieved by increasing the concentration or pressure of the reactants or by increasing the temperature of the system.

The average kinetic energy of the particles in the reactant mixture is directly proportional to the temperature of the system. As the temperature increases, the kinetic energy of the particles increases, and the particles move faster, leading to a higher chance of successful collisions and an increased reaction rate. Option B is correct.

The complete question is

Which factors can affect reaction rate?

I. The state of the reactants

II. The frequency of the collisions between particles

III. The average kinetic energy of the particles

Options:

A. I and II only

B. I, II and III

C. II and III only

D. I and III only

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The empirical formula of calcium nitride is Ca₇N₆.

The mass of nitrogen that reacted with calcium can be calculated by subtracting the initial mass of nitrogen from the final mass:

mass of nitrogen reacted = final mass of nitrogen - an initial mass of nitrogen

mass of nitrogen reacted = 0.4670 g - 0 g

mass of nitrogen reacted = 0.4670 g

The mass percent of calcium and nitrogen in the compound can be calculated as follows:

mass percent of calcium = (mass of calcium / total mass of compound) x 100%

mass percent of calcium = (2.004 g / (2.004 g + 0.4670 g)) x 100%

mass percent of calcium = 81.11%

mass percent of nitrogen = (mass of nitrogen / total mass of compound) x 100%

mass percent of nitrogen = (0.4670 g / (2.004 g + 0.4670 g)) x 100%

mass percent of nitrogen = 18.89%

We can convert the mass percent of each element to its corresponding mass in grams:

mass of calcium = 81.11 g/100 g x total mass of compound

mass of calcium = 81.11 g/100 g x (2.004 g + 0.4670 g)

mass of calcium = 1.923 g

mass of nitrogen = 18.89 g/100 g x total mass of compound

mass of nitrogen = 18.89 g/100 g x (2.004 g + 0.4670 g)

mass of nitrogen = 0.5485 g

We can then find the ratio of calcium to nitrogen by dividing the mass of each element by its atomic mass and then dividing by the smaller result:

Ca: (1.923 g / 40.08 g/mol) = 0.0478 mol

N: (0.5485 g / 14.01 g/mol) = 0.0392 mol

Dividing both values by 0.0392 mol gives:

Ca:N = 1.218:1

This ratio can be simplified by multiplying both sides by 6 (to get whole number values):

Ca:N = 7:6

The empirical formula of calcium nitride is Ca₇N₆.

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(a) NH2OH- Nitrogen is a group 5 element and has 5 valence electrons. Oxygen is a group 6 element and has 6 valence electrons. Hydrogen is a group 1 element and has 1 valence electron. Therefore, NH2OH has the formula: NH2OH

(b) AlCl2- Aluminum is a group 3 element and has 3 valence electrons. Chlorine is a group 7 element and has 7 valence electrons. Therefore, AlCl2 has the formula: AlCl2

(c) CF2Cl2- Carbon is a group 4 element and has 4 valence electrons. Fluorine is a group 7 element and has 7 valence electrons. Chlorine is a group 7 element and has 7 valence electrons. Therefore, CF2Cl2 has the formula: CF2Cl2

(d) CH2O- Carbon is a group 4 element and has 4 valence electrons. Oxygen is a group 6 element and has 6 valence electrons. Hydrogen is a group 1 element and has 1 valence electron. Therefore, CH2O has the formula: CH2O

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The conjugate acid of the Brønsted-Lowry base, H₂PO₄⁻, is: H₃PO₄.

Brønsted-Lowry base is any substance that can accept or accept an H+ ion. Bronsted-Lowry acid is a substance that donates or loses an H+ ion. A conjugate acid is an acid that is formed when a base accepts a hydrogen ion. Similarly, a conjugate base is formed when an acid donates a hydrogen ion.

If a base accepts a hydrogen ion (H+), it will become an acid. And, if an acid donates an H+ ion, it will become a base. A pair of species related through the loss or gain of H+ ion are called conjugate acid-base pairs.

According to the given question, H₂PO₄⁻ is the Brønsted-Lowry base. Now, to determine the conjugate acid, an H+ ion is added to it.

H₂PO₄⁻ + H⁺ → H₃PO₄

Therefore, the conjugate acid of H₂PO₄⁻ is H₃PO₄.

In Brønsted-Lowry theory, a molecule or an ion is considered an acid or base based on its ability to donate or accept H+ ions. Acid can lose H+ ions, and base can gain H+ ions.

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If 0.090 mole of solid NaOH is added to 1.0 liter of 0.180 m [tex]CH_3COOH[/tex]. The pH of the resulting solution is 4.74.

To solve this problem, we need to use the equation for the dissociation of acetic acid:

[tex]CH_3COOH + H_2O[/tex]⇌ [tex]CH_3COO^{-} + H_3O^+[/tex]

The addition of solid NaOH will react with the acetic acid to form sodium acetate and water:

[tex]CH_3COOH + NaOH[/tex] → [tex]CH_3COO^{-} Na^{+} + H_2O[/tex]

To calculate the pH of the resulting solution, we need to determine the new concentrations of [tex]CH_3COOH[/tex]and [tex]CH_3COO^-[/tex]. We can use the initial concentration of [tex]CH_3COOH[/tex]and the amount of NaOH added to calculate the new concentration of [tex]CH_3COOH[/tex]:

moles of [tex]CH_3COOH[/tex]= initial concentration x volume = 0.180 M x 1.0 L = 0.180 moles

moles of NaOH = 0.090 moles

moles of [tex]CH_3COOH[/tex]remaining = 0.180 moles - 0.090 moles = 0.090 moles

volume of solution = 1.0 L + 0.090 L = 1.090 L

new concentration of [tex]CH_3COOH[/tex]= moles / volume = 0.090 moles / 1.090 L = 0.0826 M

Since NaOH is a strong base, it will completely dissociate in water to form [tex]Na^+[/tex] and [tex]OH^-[/tex]. The [tex]OH^-[/tex] ions will react with the remaining [tex]CH_3COOH[/tex]to form [tex]CH_3COO^-[/tex], so the new concentration of [tex]CH_3COO^-[/tex] will be equal to the moles of NaOH added:

new concentration of [tex]CH_3COO^-[/tex] = 0.090 moles / 1.090 L = 0.0826 M

Now we can use the equilibrium expression for the dissociation of acetic acid to calculate the pH of the buffer:

[tex]Ka = [CH_3COO^{-}][H_3O^{+}] / [CH_3COOH]\\[H_3O^{+}] = Ka * [CH_3COOH] / [CH_3COO^{-}]\\[H_3O^{+}] = 1.8 * 10^{-5} * 0.0826 M / 0.0826 M\\[H_3O^{+}] = 1.8 * 10^{-5} M\\pH = -log[H_3O^{+}]\\pH = -log(1.8 * 10^{-5})\\pH = 4.74[/tex]

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To prepare a specific carboxylic acid using the malonic ester synthesis, Identify the desired carboxylic acid structure, Remove the COOH, Add a halogen atom (X), and alkyl halide for the malonic ester synthesis.

you will need an alkyl halide as a reactant. Here is a step-by-step explanation to determine the required alkyl halide:
1. Identify the desired carboxylic acid structure. For this, you should know the target carboxylic acid's molecular structure or its name.
2. Remove the carboxylic acid group (COOH) from the target molecule.
3. Add a halogen atom (X) to the remaining carbon atom where the COOH group was attached. The halogen atom could be chlorine (Cl), bromine (Br), or iodine (I).
4. The resulting molecule is the required alkyl halide for the malonic ester synthesis.
For a more specific answer, please provide the structure or name of the carboxylic acid you wish to prepare.

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The following statements on solutions, the following are as, 1- false. 2- false. 3- false.

1. The statement "a buffer can not be destroyed by adding too much strong base. it can only be destroyed by adding too much strong acid" is false. While it is true that buffers are most commonly used to resist changes in pH caused by the addition of strong acid, adding too much strong base can also destroy a buffer.

This is because a buffer works by containing both a weak acid and its conjugate base (or a weak base and its conjugate acid). If too much strong base is added to a buffer, it can convert the weak acid to its conjugate base, removing the buffer capacity.

2. The statement "adding 0.1 mol solid naoh to a 1.0 l of 0.2 m hcl solution could prepare a buffer" is false. In order to prepare a buffer, you need to have both a weak acid and its conjugate base (or a weak base and its conjugate acid) present in the solution.

The addition of NaOH to HCl will only create a strong acid-base reaction that will result in the formation of salt and water.

3. The statement "adding a small amount of acid to a buffer increases the ph of the buffer" is also false. When a small amount of acid is added to a buffer, the buffer will resist the change in pH caused by the addition of the acid.

This is because the buffer contains both a weak acid and its conjugate base (or a weak base and its conjugate acid), which can neutralize the added acid. As a result, the pH of the buffer will remain relatively unchanged.

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A gas absorbs 8.2 kJ of heat and does 7.9 kJ of work the change in internal energy of the gas is 0.3 kJ.

According to the first law of thermodynamics:

ΔE = Q - W

ΔE is the change in internal energy of the gas

Q is the heat absorbed by the gas

W is the work done by the gas

Substituting the given values:

ΔE = 8.2 kJ - 7.9 kJ

ΔE = 0.3 kJ

Thermodynamics is the branch of physics that deals with the relationships between heat, energy, and work. It is a fundamental concept in understanding how energy is transferred and transformed in physical systems, from the behavior of atoms and molecules to the macroscopic properties of matter.

Thermodynamics is based on a few fundamental laws, including the first law of thermodynamics (also known as the law of conservation of energy), which states that energy cannot be created or destroyed, only transferred or converted from one form to another. The second law of thermodynamics states that the total entropy of a closed system can only increase over time, and that heat will flow spontaneously from hotter objects to colder ones.

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Tthe reaction that replenishes( NAD+) involves the oxidation of NADH and the reduction of oxygen. The products are( NAD+), water, and ATP, which are then used in various cellular processes.

The reaction that replenishes( NAD+) is called cellular respiration, specifically, the oxidation of NADH back to( NAD+). This process occurs in the electron transport chain, which is a part of cellular respiration. The products are (NAD+), water, and ATP, which are then used in various cellular processes.
In this reaction, NADH is oxidized, meaning it loses electrons, and returns to its original form, (NAD+). This is essential for maintaining the balance of (NAD+ )and NADH in the cell and ensuring that glycolysis, the citric acid cycle, and other cellular processes can continue.
The reactant that gets reduced is oxygen (O2). Oxygen is the final electron acceptor in the electron transport chain and is essential for aerobic respiration. When oxygen accepts electrons, it is reduced to form water ([tex]H2O[/tex]).
The products of this reaction are ([tex]NAD+[/tex]), water, and energy in the form of ATP.( NAD+) is recycled and can be used again in glycolysis and the citric acid cycle to help generate more ATP. Water is a byproduct of the reaction and can be used for various cellular processes or excreted as waste.

The ATP generated is used as a source of energy for various cellular activities, including growth, maintenance, and repair.

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The rate of an SN2 reaction depends on some the concentration of both the nucleophile and the substrate. Here the nucleophile is the hydroxide ion. Substrate is 1-iodopropane.

The rate equation for an SN2,

Rate = k [substrate] [nucleophile]

k ⇒ rate constant.

Suppose the concentration of 1-iodopropane becomes four time. Also the concentration of sodium hydroxide becomes three times. Now the new rate of the reaction is,

New Rate = k [4[substrate]] [3[nucleophile]]

New Rate = k [12[substrate]] [nucleophile]

New Rate = 12k [substrate] [nucleophile]

The new rate of the reaction is 12 times the original rate. So the reaction is 12 times faster when the concentration of 1-iodopropane becomes four times and the concentration of sodium hydroxide becomes three times.

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The ratio between 1 and 2 half lives that have elapsed since the mineral contained 100% parent atoms.

Let us consider that the parent isotope decays into the daughter isotope through a process of radioactive decay with a constant half-life.

we can use the fact of the half life which is the proportion of parent to daughter isotopes which changes over the time. We have to determine that how many half-lives have elapsed since the mineral contained 100% parent atoms.

We have the proportion of parents to daughter isotopes in the mineral is 40% parent and 60% daughter. So the ratio becomes 2:3 parent to daughter isotopes.

Calculating the current ratio of 2:3 is closest to the ratio of 1:3 which occurs after two half-lives of the mineral. So we get the ratio between 1 and 2 half-lives which have elapsed since the mineral contained 100% parent atoms.

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The percent concentration by mass when 7.24 g of barium fluoride are mixed with 51.35 g of distilled water to form a solution is 12.36%.

The percent concentration by mass can be calculated using the formula:

Percent concentration = (mass of solute / mass of solution) x 100

First, we need to find the mass of the solution by adding the mass of barium fluoride (7.24 g) and the mass of distilled water (51.35 g):

Mass of solution = 7.24 g + 51.35 g = 58.59 g

Now, we can calculate the percent concentration:

Percent concentration = (7.24 g / 58.59 g) x 100 ≈ 12.36%

So, the percent concentration by mass of the solution is approximately 12.36%.

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Hence, a 2.20 molal solution of lithium bromide in water has a freezing point that is roughly -0.00409 °C.

In absorption refrigeration systems, the bromide lithium water (LiBr/H2O) solution is frequently employed as the working fluid since it is nonvolatile, nontoxic, and does not deplete the ozone layer.

We can use the following formula to get a solution's freezing point depression: ΔTf = Kf * molality

1.86 °C/m is the freezing point depression constant for water.

Inputting the values provided yields:

molality = 2.20 mol of LiBr / 1000 g of water

molality = 0.00220 mol/g

ΔTf = (1.86°C/m) * (0.00220 mol/g)

ΔTf = 0.00409°C

The freezing point of the solution is:

freezing point = 0°C - ΔTf

freezing point = 0°C - 0.00409°C

freezing point = -0.00409°C

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Metals are good conductor of heat and electricity because of the presence of loose outer electrons in metal atoms. So option A is the correct answer.

Heat conduction occurs due to the collision of the molecules and transfer of the heat energy from one to another. Electricity is conducted when particles are charged and they move in an  organized manner.

In metals there are free held electrons also called as sea of electrons, which are not specific to an individual atoms, but are loosely bound so they can move along the whole metallic frame work. Also all the metals show low resistance.

As the electrons are free to move along the total metallic framework this increases collision between particles and become conductor of heat. As the mobile electrons can move from atom to atom, they are excellent conductors of electricity.

So option A is correct.

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The complete question is

Question 4: Metals are both good heat conductors and good electrical conductors because of

A. The looseness of outer electrons in metal atoms.

B. Similarity between thermal and electrical conductive properties.

C. High elasticity of metals. relatively high densities of metals.

D. Ability of metals to transfer energy easily.

Answer:

When 5.0 mL of chlorine gas is consumed, 1.3 mL of carbon tetrachloride gas is produced.

Explanation:

The balanced chemical equation for the reaction between methane gas and chlorine gas is:

CH4(g) + 4Cl2(g) → 4HCl(g) + CCl4(g)

From this equation, we can see that for every 4 moles of chlorine gas that react, 1 mole of carbon tetrachloride is produced.

To determine the volume of carbon tetrachloride produced when 5.0 mL of chlorine gas is consumed, we need to use the ideal gas law. Assuming standard temperature and pressure (STP), which is 0°C and 1 atm, the volume of one mole of any ideal gas is 22.4 L.

First, we need to calculate the number of moles of chlorine gas consumed:

n(Cl2) = V(Cl2) / Vm(Cl2)

n(Cl2) = 5.0 mL / 22.4 L/mol

n(Cl2) = 0.00022321 mol

According to the balanced equation, 4 moles of chlorine gas react to produce 1 mole of carbon tetrachloride. Therefore, the number of moles of carbon tetrachloride produced is:

n(CCl4) = n(Cl2) / 4

n(CCl4) = 0.00022321 mol / 4

n(CCl4) = 5.58025 x 10^-5 mol

Finally, we can calculate the volume of carbon tetrachloride produced using the ideal gas law:

V(CCl4) = n(CCl4) x Vm(CCl4)

V(CCl4) = 5.58025 x 10^-5 mol x 22.4 L/mol

V(CCl4) = 0.001251 L

Rounding to the correct number of significant digits, the volume of carbon tetrachloride produced is 0.0013 L or 1.3 mL.

Therefore, when 5.0 mL of chlorine gas is consumed, 1.3 mL of carbon tetrachloride gas is produced.

The correct answer is option B. Strong bases are molecules that can release hydroxide ions (OH-) into a solution when dissolved in water.

These molecules can neutralise other molecules with lower pHs (acids) and raise the concentration of hydroxide ions in the solution because of their relatively high pH.

Hydroxide ions can react with both acids and bases to create water molecules because they are the conjugate base of water and are amphoteric.

By aggressively releasing hydroxide ions and neutralising any present acids, strong bases effectively raise the concentration of hydroxide ions in the solution.

Strong bases are typically the best option when attempting to raise the concentration of hydroxide ions in a solution due to their characteristics.

Complete Question:

Which species would increase the concentration of hydroxide in solution the most? select the correct answer below:

A. weak base

B. strong base

C. weak acid

D. strong acid

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The gas with the slowest average molecular speed at a particular temperature is chlorine, or Cl2. The right answer is 5.

The formula for the typical molecular speed is:

The atomic speed is 1/M.

Where,

The molecular mass is M.

N2 has a molecular weight of 28.01 g/mol.

F2 has a molecular weight of 37.99 g/mol.

Carbon monoxide has a molecular weight of 28.01 g/mol.

Cl2 has a molecular weight of 70.90 g/mol.

The average molecular speed decreases with increasing molecule mass. The average molecular speed increases with decreasing molecular weight.

The chlorine has the slowest average molecular speed as a result.

The substance with the slowest average molecular speed is chlorine, or Cl2. Hence option 5 is correct.

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The correct student with scientific reasoning is the first student who states that the percent error could be caused by the salt not completely dissolving, which would result in a lower measured change in heat per mole. This is a valid scientific reasoning as the dissolving of the salt is an important factor that affects the change in heat during the reaction.

The percent error could be caused by the salt not completely dissolving, therefore the change in heat per mole would be accidentally low. The percent error could be caused by mixing the reaction too quickly, the friction caused by mixing would increase the change in heat measured. The percent error could be caused by the change in pH of the solution, this would decrease the change in heat accidentally.

The second student's statement that the percent error could be caused by mixing the reaction too quickly is not a valid scientific reasoning, as mixing does not affect the change in heat produced by the reaction.

The third student's statement that the percent error could be caused by the change in pH of the solution decreasing the change in heat is also not a valid scientific reasoning, as a change in pH would not affect the change in heat produced by the reaction.

Therefore, the first student provides the correct scientific reasoning for the possible cause of the percent error in the lab.

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It is important to be concise and not provide extraneous amounts of detail.

When answering questions on the Brainly platform, you should always aim to be factually accurate, professional, and friendly. Additionally,You should also use the following terms in your answer if they are relevant to the question being asked

g enter your experimental data into columns d-g.

2. use your temperature data and equation 7.1 to determine the calories of heat released (column h) for each sample combustion. enter the calculation of q using equation 7.1 into the cells of column h with the appropriate mass of water for m. the specific heat of water for c and at

= column g entry - column f entry. report your results to the proper number of significant figures.

3. use the initial sample mass to determine the cal/g (column 1) you measured for each sample. if you used different sizes of sample and got very different results for a particular food, which value is likely to be more reliable? explain why.

4. use the mass lost in the burning (column e entry - column d entry) to determine the salg lost (column j) for each sample.

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Answer: 8.98 (rounded to two significant figures)

Explanation:  

Answer:

9

Explanation:

8.97998 to the nearest significant figure.

The mass percent of CaCO₃(s) in the eggshell sample is closest to 136%.

The number of moles of carbon dioxide produced in the reaction can be calculated from the change in pressure of the gas:

ΔP = P₂ - P₁ = 0.870 atm - 0.800 atm = 0.070 atm

n = (ΔP * V) / (R * T)

Assuming the volume of the gas is the same as the volume of the acid, we can use the initial pressure and volume of the acid to calculate the number of moles of carbon dioxide:

n = (0.070 atm * 0.100 L) / (0.0821 L atm/mol K * 298 K) = 0.00272 mol CO₂

From the balanced equation, we know that one mole of calcium carbonate produces one mole of carbon dioxide:

CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + CO₂(g) + H₂O(l)

Therefore, the number of moles of calcium carbonate in the eggshell sample is also 0.00272 mol.

The mass percent of calcium carbonate in the eggshell sample can be calculated as follows:

mass percent = (mass of CaCO₃ / mass of sample) x 100%

mass of CaCO₃ = n x molar mass of CaCO₃

The molar mass of CaCO₃ is 100.09 g/mol.

mass of CaCO₃ = 0.00272 mol x 100.09 g/mol = 0.272 g

mass percent = (0.272 g / 0.200 g) x 100% = 136%

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Answer:

The answer is 1.30

Explanation:

The equation to calculate the pH of a strong acid solution is pH = -log[H+], where [H+] is the concentration of hydrogen ions in the solution.

For a 0.050 M HBr solution, the concentration of H+ ions is also 0.050 M since HBr is a strong acid and dissociates completely in water. Therefore, the pH can be calculated as follows:

pH = -log[H+] =

ph=-log(0.050) = 1.30

So the pH of a 0.050 M HBr solution is 1.30.

The pH of a 0.050 M HBr solution is 1.30. The correct option is (a) 1.30.

What is pH?

The negative of the logarithm to base 10 of the hydrogen ion concentration (expressed in mol/L) is referred to as pH. pH can be defined using the following equation:

pH = - log [H+]

Where [H+] is the concentration of hydrogen ions in moles per liter. It ranges from 0 to 14. A pH of 7.0 is neutral. If the pH is below 7, the solution is acidic, and if it is above 7, the solution is alkaline (basic).

HBr is the chemical formula for hydrogen bromide, a diatomic molecule consisting of hydrogen and bromine. It is a colorless gas with a strong odor that fumes in moist air. It is a potent acid that reacts vigorously with water to form hydrobromic acid.

In an aqueous solution, hydrobromic acid is the resulting acid. For a 0.050 M HBr solution, we can use the equation:

pH = - log [H+]

pH = - log [0.050]

pH = 1.30

Therefore, the pH of a 0.050 M HBr solution is 1.30.

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The decrease in temperature when 8.5 L at 25.0 °C is compressed to 4.00 L is 86.7 °C.

This is a problem involving the ideal gas law, which relates pressure (P), volume (V), number of moles (n), and temperature (T) of a gas:

PV = nRT

where R is the gas constant. Assuming the number of moles is constant, we can write:

P₁V₁/T₁ = P₂V₂/T₂

where the subscripts 1 and 2 refer to the initial and final states of the gas, respectively.

We can use this equation to solve for the final temperature (T₂), given the initial conditions (P₁ = 1 atm, V₁ = 8.5 L, and T₁ = 25.0 °C) and the final volume (V₂ = 4.00 L):

P₁V₁/T₁ = P₂V₂/T₂

T₂ = (P₂V₂/T₁) * [tex](P₁V₁)^-1[/tex]

The pressure (P) is not given, but we can assume that it remains constant during the compression process, which is a reasonable assumption if the compression is slow and controlled. Let's assume a pressure of 1 atm.

T₂ = (1 atm * 4.00 L / (25.0 °C + 273.15)) *[tex](1 atm * 8.5 L)^-1[/tex]

T₂ = 211.5 K

The final temperature of the compressed gas is 211.5 K. To calculate the decrease in temperature, we need to find the change in temperature from the initial temperature of 25.0 °C:

ΔT = T₂ - T₁

ΔT = 211.5 K - (25.0 °C + 273.15)

ΔT = -86.7 °C.

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An equilibrium is reached when the concentrations of the reactants and products do not change, and the rate of the forward reaction is equal to the rate of the reverse reaction.

Based on this definition, the following statements apply to an equilibrium:

1. The concentrations of the reactants and the products do not change.

2. The rate of the reverse reaction does not change.

The third statement, "the rate of the forward reaction is twice as fast as the rate of the reverse reaction," does not apply to an equilibrium. This is because, in equilibrium, the rate of the forward reaction must be equal to the rate of the reverse reaction for the concentrations to remain constant. If the forward reaction was faster, it would cause the concentrations to change, and the system would not be in equilibrium.

In summary, a system is at equilibrium when the concentrations of reactants and products do not change, and the rates of the forward and reverse reactions are equal. The first two statements apply to an equilibrium, while the third statement does not.

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The pH at the equivalence point for a weak acid-strong base titration is affected by the dissociation constant of the weak acid and the hydrolysis of the resulting salt, leading to a pH above 7 at the equivalence point.

The pH at the equivalence point for a weak acid-strong base titration is affected by two main factors: the dissociation constant (Ka) of the weak acid and the hydrolysis of the resulting salt.
1. Dissociation constant (Ka) of the weak acid: The Ka represents the extent to which the weak acid ionizes in water. A smaller Ka value indicates a weaker acid, which means it ionizes less in solution. Since the equivalence point occurs when equal amounts of H+ and OH- ions have reacted, the degree of ionization of the weak acid will influence the pH of the solution.
2. Hydrolysis of the resulting salt: When a weak acid reacts with a strong base, a salt and water are formed. The anion of the salt, which is a conjugate base of the weak acid, can undergo hydrolysis, reacting with water to form a small amount of the weak acid and hydroxide ions (OH-). This hydrolysis increases the concentration of OH- ions in the solution, leading to a pH above 7 at the equivalence point.

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The maximum mass of H2O that can be produced from 51.7 g of NH3 and O2 is approximately 34.9 g.

The balanced equation for the reaction between ammonia and oxygen gas to produce nitric oxide and water is:

4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g)

According to the balanced equation, 4 moles of NH3 reacts with 5 moles of O2 to produce 6 moles of H2O. Therefore, the mole ratio of NH3 to H2O is 4:6, or 2:3.

If the ratio of NH3 to O2 is smaller than the actual ratio, then NH3 is limiting and vice versa.

Let's first calculate the number of moles of NH3 and O2 present in the reaction mixture:

moles of NH3 = 51.7 g / 17.03 g/mol = 3.03 mol

moles of O2 = 51.7 g / 32.00 g/mol = 1.62 mol

Now let's calculate the ratio of NH3 to O2:

NH3/O2 = 3.03 mol / 1.62 mol = 1.87

The actual ratio of NH3 to O2 is larger than the mole ratio of 2:1, which means that O2 is limiting.

The mole ratio of O2 to H2O is 5:6, which means that 5 moles of O2 react with 6 moles of H2O. Therefore, the maximum number of moles of H2O that can be produced from 1.62 mol of O2 is:

moles of H2O = (6/5) x 1.62 mol = 1.94 mol

Finally, we can calculate the maximum mass of H2O produced using its molar mass:

mass of H2O = 1.94 mol x 18.02 g/mol = 34.9 g

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