an unknown mineral sample scratches fluorite but cannot scratch apatite. what is the approximate hardness of this mineral?

Carboxylic acids are more acidic than water or ethyl alcohol esters due to their stronger resonance stabilization. Carboxylic acids contain a carboxyl group (COOH) that is able to stabilize the extra electron density of the conjugate base (COO-) through resonance. The more electron-withdrawing atoms in the carboxyl group, the more stable the resonance structure and therefore the stronger the acid. Water and ethyl alcohol esters, on the other hand, have less electron-withdrawing atoms, so their conjugate base is not as stable and their acidity is less than that of carboxylic acids.

Additionally, carboxylic acids tend to have smaller molecules than water or ethyl alcohol esters. This means that their conjugate base will have a stronger interaction with the proton and therefore the acid is stronger. In contrast, water and ethyl alcohol esters are larger molecules and their conjugate base is less capable of stabilizing the proton and thus making the acid less acidic.  

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The degree of polymerization of this polymer if the number-average molecular weight is 500000 g/col is 4000.

The degree of polymerization (DP) is the number of repeat units in a polymer chain. DP is a useful concept that provides information about the size of the molecule and its physical characteristics. DP is defined as the molecular weight of the polymer divided by the molecular weight of the repeating unit, which is usually determined using an average value. It is denoted as “n”.

The number-average molecular weight (Mn) is the average molecular weight of a polymer chain, calculated based on the number of polymer molecules in the sample. Mn is obtained by dividing the total weight of the sample by the total number of molecules in the sample, which is usually determined by light scattering or gel permeation chromatography (GPC). Mn provides information about the average size of a molecule in a sample. It is denoted as “Mn”.

Formula to calculate degree of polymerization

n = molecular weight of the polymer/molecular weight of the repeating unit

Given,

Now we have to find the weight of repeating unit (W) which can be obtained by the formula,

W = Mn / nW = 500000 / nGiven that number-average molecular weight (Mn) = 500000 g/col

Hence, the degree of polymerization of this polymer if the number-average molecular weight is 500000 g/col is 4000.

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The overall equation for the synthesis of isopentyl acetate is:



Acetic Anhydride + Isopentyl Alcohol → Isopentyl Acetate + Water



The mechanism for this reaction is as follows:




Step 1: Protonation of the alcohol by the acetic anhydride



Acetic Anhydride + Isopentyl Alcohol → Isopentyl Acetate + Water



Step 2: Deprotonation of the newly formed acetate by the water, producing isopentyl acetate



Acetic Anhydride + Isopentyl Alcohol + Water → Isopentyl Acetate + Acetic Acid



Therefore, the synthesis of isopentyl acetate involves the reaction between acetic anhydride and isopentyl alcohol, followed by the deprotonation of the acetate by water.
Isopentyl acetate is an ester formed from isopentyl alcohol and acetic acid, which is used as a solvent in the production of essential oils and perfumes. In this reaction, the reaction between isopentyl alcohol and acetic acid is catalyzed by sulfuric acid. The mechanism of the reaction can be explained in terms of the Fischer esterification mechanism. The Fischer esterification mechanism is a chemical reaction that occurs between an alcohol and a carboxylic acid to produce an ester. This mechanism involves the attack of the alcohol's oxygen atom on the carboxylic acid's carbonyl carbon atom. The carbonyl oxygen atom, which is double-bonded to the carbonyl carbon atom, is then deprotonated by the acid catalyst, creating an intermediate. The intermediate then undergoes a proton transfer reaction to produce the final product. The overall equation and mechanism for the synthesis of isopentyl acetate are as follows: CH₃COOH + CH₃CH₂CH(CH₃)OH ⇔CH₃COOCH₂CH(CH3)₂ + H₂OIn this reaction, sulfuric acid is used as a catalyst to speed up the reaction rate. The reaction takes place between isopentyl alcohol and acetic acid to produce isopentyl acetate and water.

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Answer:

A - 9.6 mol.

Explanation:

Took the test.

6-step synthesis of a carboxylic acid.

This question requires a 6-step synthesis of a carboxylic acid from ethyne using the reagents provided. Here is the solution:

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When you mix baking soda and vinegar, a chemical reaction occurs that produces carbon dioxide gas, water, and a type of salt called sodium acetate.

Before: Before mixing baking soda and vinegar, they are both in their separate states. Baking soda is a white powder, and vinegar is a clear liquid.

During: When you mix the baking soda and vinegar, the baking soda (sodium bicarbonate) reacts with the vinegar (acetic acid) to produce carbon dioxide gas (CO2), water (H2O), and sodium acetate (NaC2H3O2).

After: After the chemical reaction has taken place, you will see bubbles of carbon dioxide gas being released. The solution will also become cloudy as the sodium acetate precipitates out. The resulting mixture may feel warmer due to the exothermic nature of the reaction (meaning it releases heat).

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The result of mixing equal volumes of 1 M aluminum chloride, 2 M magnesium chloride, and 1 M potassium chloride solution is a colorless and odorless solution that contains six ions in equal amounts.

The AlCl3 dissociates into three ions, one Al3+, and three Cl-.The MgCl2 dissociates into three ions, one Mg2+ and two Cl-.The KCl dissociates into two ions, one K+, and one Cl-.As a result, when the aluminum chloride, magnesium chloride, and potassium chloride solutions are mixed in equal volumes, a total of six ions are present, consisting of one Al3+, one Mg2+, one K+, and three Cl- ions. The composition of the solution, which has six ions in equal amounts, is as follows:

Al3+ (aq) + Mg2+ (aq) + K+ (aq) + 3Cl- (aq) → colorless, odorless solution.

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From the balanced equation, we know that 3 moles of H₂ produces 2 moles of NH₃.Therefore, to find the moles of NH₃ produced from 4.8 moles of H₂, we can set up a proportion 3 moles H₂ / 2 moles NH₃ = x moles H₂ / 4.8 moles H₂.

In chemistry, mole is a unit of measurement used to express amounts of a chemical substance. It is defined as the amount of a substance that contains the same number of entities (such as atoms, molecules, or ions) as there are in 12 grams of pure carbon-12, which is approximately 6.022 x 10^23 entities. This number is known as Avogadro's number, and it is a fundamental constant in chemistry.

Moles are used to quantify chemical reactions and calculate the amount of reactants needed to produce a certain amount of product, or the amount of product that can be obtained from a given amount of reactants.

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Answer: To obtain a 0.113 M HNO3 solution, you need to dilute 49 mL of 12 M HNO3 solution to a final volume of 5220 mL (or 5.22 L) by adding enough water to make up the difference.

Explanation: The stock HNO3 solution is 12 M and has a volume of 49 ml.

To get a 0.113 m HNO3 solution, we must dilute it to a certain volume. The volume to which it must be diluted is a mystery.

Let the final volume be V liters. The stock HNO3 solution's volume is 49 mL, which equals 0.049 L.

HNO3's molarity is 12 M.

We must use the formula to calculate the required volume of diluted solution, C1V1 = C2V2

where C1 is the concentration of the stock solution, V1 is the volume of the stock solution used, C2 is the desired concentration of the diluted solution, and V2 is the final volume of the diluted solution.

In this case, we have:

C1 = 12 M

V1 = 49 mL

C2 = 0.113 M

V2 = unknown

Let's do some math.

12 M x 49 mL = 0.113 M x V2

(12 x 0.049) / 0.113 = 5.22 L

The diluted volume is 5.22 L.

The stock HNO3 solution of 49 ml must be diluted to a volume of 5.22 L to obtain a 0.113 m HNO3 solution.

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The aluminum chloride and sodium chloride are dissolved in water as aqueous solutions

Why aluminum and sodium chloride react with each other?

The balanced equation for the single displacement reaction between sodium and aluminum chloride is as follows:

Na(s) + AlCl3(aq) → Al(s) + NaCl(aq)

This is a single displacement reaction because sodium is displacing aluminum from its compound aluminum chloride. The products of the reaction are aluminum and sodium chloride.

The equation balanced is because there are equal numbers of atoms each element on both sides of the equation. The coefficients in front of each molecule indicate the number of molecules of each compound or element that are involved in the reaction.

Na(s) + AlCl3(aq) → Al(s) + NaCl(aq) Phases are optional in the equation, but they can be included to indicate the physical state of each substance.

In this equation,

(s) indicates that sodium is a solid,

(aq) indicates that aluminum chloride and sodium chloride are dissolved in water as aqueous solutions,

and (s) indicates that aluminum is also a solid.

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When starch is treated with iodine solution, its color changes to Blue-black. Option c is correct.

This reaction is used as a test for the presence of starch in a sample. Iodine reacts with the helical amylose component of starch to form a dark blue complex, while amylopectin, which has a branched structure, forms a less intense blue color. This color change occurs due to the formation of an iodine-starch complex, which has a characteristic blue-black color. Therefore, the intensity of the color indicates the amount of starch present in the sample. Hence, option c is correct choice.

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--The complete question is, When starch is treated with iodine solution, its color changes to

(A) Yellow

(B) Red

(C) Blue-black

(D) Green--

To determine the volume of a 5% acetic acid by mass solution necessary to neutralize 25.0 ml of 0.10 m is 300 mL

To calculate the volume of the acetic acid solution necessary to neutralize, you will use the formula:

M₁V₁ = M₂V₂

Where,

M₁ = molarity of acetic acid

V₁ = volume of acetic acid

M₂ = molarity of sodium hydroxide

V₂ = volume of sodium hydroxideInitially

You need to calculate the moles of NaOH in 25 ml of 0.10 M NaOH;

Molarity (M) = 0.10 M

Moles (n) = M × Vn = 0.10 × 25/1000n = 0.0025 mol of NaOH

To neutralize NaOH, you need the same number of moles of acetic acid;

1 mol of NaOH reacts with 1 mol of acetic acid0.0025 mol NaOH reacts with 0.0025 mol acetic acid

Concentration of acetic acid = 5%

Mass of acetic acid in 100 ml of solution = 5 g

Density of solution = 1.0 g/ml

Therefore, volume of acetic acid solution that is necessary to neutralize 25.0 ml of 0.10 m

V = (0.0025 mol acetic acid) x (60.05 g acetic acid/1 mol acetic acid) x (1/5 g acetic acid in 100 ml of solution) x (1000 ml/1 L) x (1/1.0 g/ml)

V = 0.30 L of acetic acid solution

V = 300 mL of acetic acid solution (3 significant figures)

Hence, the volume of the acetic acid solution necessary to neutralize 25.0 ml of 0.10 m is 300 mL.

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Answer: Hot Rocks

Explanation:

a) The total pressure of the mixture is 434 torr

b) The mass of each gas is, N₂ = 40.56 g, O₂ = 21.76 g, He = 3.20 g

a) The total pressure of the mixture is calculated by adding all the values of partial pressures of the N₂, O₂, and He

215 torrs of N₂ + 102 torr of O₂ + 117 torr of He

= 434 torr

Thus, the total pressure of the mixture is 434 torr

b) The mass of each gas in the 1.35 L sample of the mixture at 25.0 C can be calculated using the ideal gas law: PV = nRT.

The amount of each gas present is equal to the total moles of gas, n, in the sample.

n = (PV)/(RT)

where P is the partial pressure of the gas in the mixture,

V is the volume of the sample (1.35 L),

R is the ideal gas constant (0.08206 L atm mol⁻¹ K⁻¹), and

T is the temperature in Kelvin (298.15 K).

For N₂: n = (215 torr x 1.35 L)/(0.08206 L atm mol⁻¹ K⁻¹ x 298.15 K) = 1.45 moles
For O₂: n = (102 torr x 1.35 L)/(0.08206 L atm mol⁻¹ K⁻¹ x 298.15 K) = 0.68 moles
For He: n = (117 torr x 1.35 L)/(0.08206 L atm mol⁻¹ K⁻¹ x 298.15 K) = 0.80 moles

The mass of each gas is equal to the moles multiplied by the molar mass of the gas:

For N₂: 1.45 moles x 28.01 g/mol = 40.56 g
For O₂: 0.68 moles x 32.00 g/mol = 21.76 g
For He: 0.80 moles x 4.00 g/mol = 3.20 g

Thus, the mass of each gas is, N₂ = 40.56 g, O₂ = 21.76 g, He = 3.20 g.

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Answer:

chelated zinc is more easily absorbed than zinc on it's own.

Answer:

43.1gramms

Explanation:

change the temperatures to kelvin

90--363

40--313

50grams of water are saturated at 90 degree celcius.

then,

50___363

x_____313

then cross multiply

363x=15650

divide both sides by 363

x=43.1gramms

The molarity of the solution is 1.0 m

The first step is to convert the mass of KCl to moles:

Number of moles of KCl = 74.5 g / 74.5 g/mol = 1.0 mol

Next, we need to calculate the mass of water in kilograms:

Mass of water = 1000 mL x 1 L/1000 mL x 1 kg/L = 1 kg

Now we can calculate the molality of the solution:

Molality = moles of solute / mass of solvent (in kg)

Molality = 1.0 mol / 1 kg = 1.0 m

Therefore, the molality of the solution is 1.0 m.

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Methane and carbon dioxide are both greenhouse gases that are crucial in controlling the temperature of Earth's atmosphere.

Both natural processes like respiration and volcanic eruptions, as well as human activity like burning fossil fuels, emit carbon dioxide (CO2) into the atmosphere. It aids in keeping the planet warm enough to support life by retaining heat in the atmosphere. Carbon dioxide levels that are too high, however, can exacerbate climate change and global warming.

Methane (CH4) is another greenhouse gas that is emitted into the atmosphere as a result of human activity such as cattle husbandry and natural gas production as well as natural processes such as decomposition. Even though it decomposes more quickly in the atmosphere than carbon dioxide, it is even more efficient at trapping heat.

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The lewis structure for ammonia NH₃ is:

    H
      |
   : N - H
      |
     H

And there are no formal charges.

To draw the Lewis structure for NH₃, follow these steps:

1. Determine the total number of valence electrons: Nitrogen (N) has 5 valence electrons, and each Hydrogen (H) atom has 1 valence electron. Since there are 3 Hydrogen atoms, the total valence electrons are 5 + (3 * 1) = 8.

2. Identify the central atom: Nitrogen is the central atom because it has the highest bonding capacity (it can form 3 bonds).

3. Place the central atom and surround it with Hydrogen atoms: Write the symbol for Nitrogen and place the 3 Hydrogen atoms around it in a trigonal planar arrangement.

     H
      |
H - N - H

4. Connect the atoms with single bonds: Create a single bond between Nitrogen and each Hydrogen atom by placing a pair of electrons (a line) between them. This uses 6 valence electrons (2 for each bond).

5. Distribute the remaining valence electrons: We have used 6 valence electrons so far, and there are 2 more left. Place the remaining 2 electrons as a lone pair on the central Nitrogen atom.

     H
      |
   : N - H
      |
     H

6. Check the octet rule: Each Hydrogen atom has 2 electrons (1 bond), and Nitrogen has 8 electrons (3 bonds and 1 lone pair). All atoms satisfy the octet rule.

7. Determine formal charges: In NH₃, there are no formal charges, as each atom has the same number of valence electrons as in its neutral state.

The Lewis structure for NH₃ is now complete.

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Dream car: 2022 Tesla Model S; Second car: 2022 Toyota Camry

To calculate the amount spent on gas in one year for each car, we need to multiply the number of gallons of gas used in one year by the price per gallon.

For the dream car: 426.9 gallons x $3.00/gallon = $1280.70 spent on gas in one year.

For the second car: 500 gallons x $3.00/gallon = $1500 spent on gas in one year.

Therefore, you would spend $1280.70 on gas for the dream car and $1500 on gas for the second car in one year.

The Tesla Model S is an electric car, so it does not have miles per gallon on the highway.

The Toyota Camry has a highway mpg of 39.

Balanced equation for the combustion of octane: 2C8H18 + 25O2 → 16CO2 + 18H2O

The first car (Tesla Model S) uses no gasoline, so it does not use any gallons of gas in one year.

Converting 1 gallon to mL: 1 gallon = 3785.4 mL

Assuming you drive the Toyota Camry 15,000 miles in one year and get 39 mpg on the highway: 15,000 miles ÷ 39 miles per gallon = 384.6 gallons

Converting gallons to mL: 384.6 gallons x 3785.4 mL/gallon = 1,455,047.64 mL

The second car (Toyota Camry) uses 384.6 gallons of gas in one year.

Converting gallons to mL for the second car: 384.6 gallons x 3785.4 mL/gallon = 1,455,047.64 mL

The Tesla Model S is more efficient in terms of gas use since it uses no gasoline.

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A closely packed mineralized matrix, which comprises hydroxyapatite, collagen fibres, and osteocytes as well as trace quantities of other proteins and minerals, makes up the majority of compact bone.

Compact bone is one of the two types of osseous tissue that makes up bones in vertebrates. It forms the outer layer of bone and provides strength and support to the skeleton. The structure of compact bone is composed of a tightly packed mineralized matrix, which is made up of hydroxyapatite crystals and collagen fibers. The hydroxyapatite crystals provide hardness and rigidity to the bone while the collagen fibers give it flexibility and resilience. Osteocytes, or bone cells, are also found in the mineralized matrix, which are responsible for maintaining the bone tissue. Additionally, small amounts of other proteins and minerals are present in the matrix, including calcium, phosphate, and magnesium. Together, these components create a strong and durable structure that is able to support the body's weight and withstand stress and strain.

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The metal that will respond to the added temperature by increasing is metal A because it has the lowest heat capacity.

The metal with the smallest heat capacity will have the largest increase in temperature if the same amount of heat is added to each of their systems. This is because metals with smaller heat capacities require less heat energy to increase their temperature compared to those with larger heat capacities.

Therefore, metal A with the heat capacity of 0.3 J/g°C will have the largest increase in temperature if the same amount of heat is added to each of their systems, followed by metal B with 0.4 J/g°C and metal C with 0.5 J/g°C.

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Answer:

Explanation:

A lever is a simple machine that can be used to increase the force or distance of an applied effort. The three main parts of a lever are the fulcrum, resistance arm, and effort arm.

The mechanical advantage of a lever depends on the ratio of the length of the effort arm to the length of the resistance arm. A longer effort arm will require less force to lift a load, but will require more distance to be moved. Conversely, a shorter effort arm will require more force to lift a load, but will require less distance to be moved.

The helium nucleus with two protons and two neutrons has the greatest mass. This is because protons and neutrons have much greater mass than electrons. The nucleus of a helium atom is made up of two protons and two neutrons, so it has a greater mass than four individual protons.
Out of the given groups of particles, a helium nucleus with two protons and two neutrons has the greatest mass.What is a nucleus?

A nucleus is the center of an atom, containing positively charged protons and uncharged neutrons. It's where almost all of an atom's mass is located. Electrons, which are negatively charged particles that orbit the nucleus in shells, are also present in an atom. The mass of an atom is largely determined by the mass of its nucleus, which is made up of positively charged protons and uncharged neutrons. Since the helium nucleus is composed of two protons and two neutrons, it is the group of particles with the greatest mass. Thus, out of the given groups of particles, a helium nucleus with two protons and two neutrons has the greatest mass.

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At 31.52° Celsius temperature will argon have a density of 10.3 g/L and a pressure of 6.43 atm . This is given by ideal gas law.

An ideal gas is a theoretical gas composed of many randomly moving point particles that do not interact with one another. The ideal gas concept is useful because it obeys the ideal gas law, which is a simplified equation of state, and is amenable to statistical mechanics analysis. The requirement of zero interaction is frequently relaxed if the interaction is perfectly elastic or regarded as point-like collisions, for example. When intermolecular forces and molecular size become important, the ideal gas model tends to fail at lower temperatures or higher pressures. It also fails for most heavy gases, including many refrigerants,[2] as well as gases with strong intermolecular forces, most notably water vapor. At high pressures, the volume of a real gas is frequently much larger than that of a pure gas.

using the formula

P × M = d × R × T

Where P = pressure = 6.43 atm

m= molar mass = 40 g

d = density = 10.3 g/L

T = temperature

R = 0.082057 L atm K⁻¹ mol⁻¹

solving for T ,

T = 31.52°C

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According to the given options, option "II only" will increase the pH of an H2CO3/HCO+3 buffer solution.

Buffer solution- A buffer solution is a solution that resists changes in pH when small amounts of an acid or a base are added to it.

H2CO3/HCO+3 buffer- A buffer that consists of a weak acid and its conjugate base is known as an acid-buffer or a weak acid-buffer. For example, carbonic acid (H2CO3) and bicarbonate (HCO3−) are combined in a buffer solution that has a weak acid (H2CO3) and its conjugate base (HCO3−). Carbonic acid (H2CO3) and bicarbonate (HCO3−) are combined in a buffer solution that has a weak acid (H2CO3) and its conjugate base (HCO3−).

The chemical equation for the carbonic acid-bicarbonate buffer is:

H2CO3 ⇌ H+ + HCO3−

This reaction shows that the buffer solution contains both carbonic acid (H2CO3) and bicarbonate (HCO3−) ions. H+ and HCO3− ions are formed when carbonic acid (H2CO3) dissociates in water (H2O).

Increasing the pH of a buffer solution- The pH of a buffer solution can be increased by adding a strong base, which would react with the buffer's weak acid to form its conjugate base. In this scenario, sodium bicarbonate (NaHCO3) is a strong base.

Therefore, option "II only" is the correct answer.

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The total volume (in ml) of the titrant that has been dispensed from the burette is 13.75 ml.

A burette is a laboratory apparatus that is used in analytical chemistry to dispense a liquid reagent in a precise and controlled volume to conduct experiments. It consists of a graduated glass tube with a stopcock at the bottom and a funnel at the top that is attached to a burette stand.

Titrant refers to a solution of known concentration that is slowly added to a solution of unknown concentration until a reaction has been completed. When the reaction has been completed, the amount of titrant that has been added is calculated from the burette readings and used to determine the concentration of the unknown solution given that the reaction equation is known.

Here, initial burette reading (Vi) = 3.50 ml, final burette reading (Vf) after first addition = 12.75 ml

Volume of titrant used in the first addition = Vf - Vi = 12.75 ml - 3.50 ml = 9.25 ml

Final burette reading (Vf) after second addition = 15.60 ml

Volume of titrant used in the second addition = Vf - Vi = 15.60 ml - 12.75 ml = 2.85 ml

Final burette reading (Vf) after third addition = 17.25 ml

Volume of titrant used in the third addition = Vf - Vi = 17.25 ml - 15.60 ml = 1.65 ml

The total volume of titrant that has been dispensed from the burette is the sum of the volume of titrant used in all three additions. Therefore, Total volume of titrant = Volume of titrant in first addition + Volume of titrant in second addition + Volume of titrant in third addition= 9.25 ml + 2.85 ml + 1.65 ml= 13.75 ml

Hence, the total ml of titrant that has been dispensed from the burette is 13.75 ml.

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Answer:

Because if we changed the subscript number we will change the identity of the compound and we Well creat a new compound  or substance different than what they gave us to balance also the law of conservation of mass states that the mass cannot be created nor destroyed.

Explanation:

The answer that best defends Meika's position that there is a systematic error associated with the experiment where you qualitatively observed reactions and recorded observations is option C: your work needs to be of higher quality than you have previously demonstrated.

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