Complete the following operation and then enter your answer as a decimal with the correct number of significant figures. (17.543 + 2.19) × 1.04821 = (17.543+2.19)×1.04821= ?

Final answer:

To determine the volume of a 1:5000 w/v solution that can be made from 125 mL of a 0.2% w/v solution of benzalkonium chloride, we calculate the mass of the solute in the initial solution and divide it by the concentration of the desired dilute solution, giving us 1250 mL.

Explanation:

To calculate the target volume of a 1:5000 w/v solution from a 0.2% w/v solution of benzalkonium chloride, we first need to understand the concentration terms. A 0.2% w/v solution means 0.2 g of solute is present in every 100 mL of solution. For a 1:5000 w/v solution, there is 1 g of solute in 5000 mL of solution, or essentially y, 0.0002 g/mL (1 g / 5000 mL).

We then figure out how much benzalkonium chloride is in the initial 125 mL of the 0.2% solution. Since 0.2% w/v is equivalent to 0.2 g/100 mL, we have 0.2 g in 100 mL, hence in 125 mL, we'll have 0.25 g (since 125 mL is 1.25 times 100 mL).

To work out how much of the 1:5000 solution we can make with 0.25 g, we use the concentration of the 1:5000 solution, which is 0.0002 g/mL. Dividing the total available mass of solute (0.25 g) by the concentration (0.0002 g/mL), we get 1250 mL. Thus, the answer is a. 1250 mL.

Answer:

Confusion is eliminated when the correct measurement is applied

Explanation:

A measurement standard is often described as the reference to which other measurements are judged or based on. Most times, measurement standard are used to determine how accurate an experimental measurement is.

A measurement standard may not eliminate confusion when the correct measurement is applied. If the scientist does not agree with the measurement standard being used, then problem will set in.

The statement 'A standard need not agree with a previously defined size' does not describe a measurement standard because consistency with previously defined sizes is crucial for accuracy. Measurement standards ensure comparability of data across various domains, driving advancements in both science and technology.

The statement that does not describe a measurement standard is 'A standard need not agree with a previously defined size.' Measurement standards must indeed be consistent with previously defined sizes to ensure accuracy and eliminate confusion. Measurement standards are crucial to avoid ambiguity and to make sure that experimental data from different labs can be compared accurately. By having unchanging standards, like for the size of a meter, we ensure that a unit of measure remains constant over time, which is indispensable for consistency in scientific experiments and technology development.

Furthermore, the correct measurement standards are essential for the growth of technology as they allow for precise and reliable data. The relationship between science and technology is symbiotic; they drive each other's advancement. As technology improves, new measurement techniques become possible, leading to more detailed observations and more accurate scientific experiments, which in turn can further advance technology.

Answer:

The volume you need to transfer from the stock solution is 0.145 l

Explanation:

Since the number of moles of lactose in the volume of stock solution that you transfer will be the same as the number of moles of lactose in the final solution, you can use this expression:

number of moles in volume to transfer = number of moles in the final solution

Since number of moles = concentration * volume (if the concentration is expressed in molarity), then:

Ci * Vi = Cf * Vf

where:

Ci = concentration of the stock solution.

Vi = volume of the stock solution to be transferred.

Cf = concentration of the final solution

Vf = volume of the final solution

Then, replacing with the data:

518 mM * Vi = 16.7 mM * 4.5 l

Vi = 16.7 mM * 4.5 l / 518 mM

Vi = 0.145 l or 145 ml

Notice that any concentration unit can be used, as long as the units of the concentration of the stock and final solution are the same.

Answer:

In the second step, the chemist must measure 8.3 ml of concentrated acid

Explanation:

The concentration of the final solution can be obtained using the pH value:

pH = -log[H] = 0.60

[H] = 10^(-0.60) = 0.25 M

Then, the final concentration of HCl will be 0.25 M because HCl is a monoprotic acid, which means that HCl only has one hydrolyzable proton. Therefore: [HCl] = [H].

The number of moles of HCl in the final solution will be equal to the number of moles present in the volume taken from the stock solution:

n° of moles in the volume taken from stock solution = n° moles in the final solution.

The number of moles can be calculated as follows:

number of moles = concentration * volume

Then:

Ci * Vi = Cf * Vf

where

Ci = concentration of the stock solution

Vi = volume taken from the stock solution

Cf = concentration of the final solution

Vf = volume of the final solution

Replacing with the data, we can obtain Vi:

6.0 M * Vi = 0.25 M * 200.0 ml

Vi = 8.3 ml

Answer:

I think it would be:

NaCO3 (s)-->Na2O (s) + CO2 (g)

The balanced chemical equation when Sodium carbonate heated to produces sodium oxide and carbon dioxide is as,

[tex]Na_{2} CO_{3} (s)[/tex] → [tex]Na_{2} O (s) + CO_{2} (g)[/tex]

The above reaction is thermal decomposition reaction.

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Explanation:

Relation between molarity and molar mass is as follows.

             Molarity = [tex]\frac{mass}{\text{molar mass}} \times \frac{1000}{V (in ml)}[/tex]

It is given that mass is 1 mg/ml which is also equal to [tex]10^{-3}[/tex] g.

Molecular mass = 58 Da = 58 g/mol

Volume = 1 ml

Therefore, calculate molarity as follows.

         Molarity = [tex]\frac{mass}{\text{molar mass}} \times \frac{1000}{V (in ml)}[/tex]

                       = [tex]\frac{10^{-3}g}{58 g/mol} \times \frac{1000}{1 ml}[/tex]  

                       = 0.0172 molar

It is known that 1 molar equals 1000 millimolar.

So,               0.0172 molar = [tex]0.0172 molar \times \frac{1000 millimolar}{1 molar}[/tex]

                                          = 17.2 millimolar

Thus, we can conclude that the concentration of given solution is 17.2 millimolar.

Answer:

The correct option is: A. H₂SO₄

Explanation:

Acid is a charged or a neutral molecule that is a proton donor and electron pair acceptors.

Acids can be classified into monoprotic acids and polyprotic acids.

Monoprotic acids are the acids that can release only one proton on dissociation.

Whereas, polyprotic acids are the acids that can release more than one proton on dissociation.

Diprotic acid is a type of polyprotic acid that can release two protons on dissociation. Example: H₂SO₄

A diprotic acid is an acid that contains two ionizable hydrogen atoms per molecule. Among the provided options, H2SO4 or sulfuric acid is such a diprotic acid. It ionizes in two stages, forming sulfates and hydrogen sulfates.

The question asks about which of the given substances is a diprotic acid. Diprotic acids are those that contain two ionizable hydrogen atoms per molecule, which can release two protons or hydrogen ions. The ionization (release of protons) occurs in two steps: the first ionization generally takes place to a greater extent than the second.

By examining the chemical formulas of the options provided, we can identify H2SO4 (Sulfuric acid) as a diprotic acid. The ionization process works as following:

A significant attribute of diprotic acids like sulfuric acid is that they form both sulfates (e.g., Na2SO4) and hydrogen sulfates (e.g., NaHSO4).

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Answer:

n = 1.48 mol/s

Explanation:

ideal gas:

⇒ n = PV/RT

∴ T = 1.60 E2 °C = 160°C = 433 K

∴ R = 0.082 atm.L/K.mol

∴ P = 49.3 psig * ( atm/ 14.6959psig ) = 3.35 atm

∴ V = 940 L/min

⇒ n =  (( 3.35 )*( 940 )) / (( 0.082 )*( 433 ))

⇒ n = 88.813 mol/min * ( min / 60s )

⇒ n = 1.48 mol/s

Answer: The mass of proton is [tex]1.67\times 10^{-33}Gg[/tex]

Explanation:

Proton is one of the sub-atomic particle which is present in the nucleus of the atom.

We know that:

Mass of proton = [tex]1.67\times 10^{-27}kg[/tex]

To convert this into Giga grams, we use the conversion factor:

[tex]1Gg=1\times 10^6kg[/tex]

Converting the given value into Giga grams, we get:

[tex]\Rightarrow 1.67\times 10^{-27}kg\times \frac{1Gg}{1\times 10^6kg}=1.67\times 10^{-33}Gg[/tex]

Hence, the mass of proton is [tex]1.67\times 10^{-33}Gg[/tex]

Answer:

In the third tube, the concentration is 0.16 ug/mL

Explanation:

In the first step, the solution is diluted by 5. Then, the concentration will be

20 ug/mL / 5 = 4 ug/mL

Then, in the second step this 4 ug / ml solution is diluted by a factor of five again:

4 ug /ml / 5 = 0.8 ug/mL

This solution is then diluted again by 5 and the concentration in the third tube will be then:

0.8 ug/mL / 5 = 0.16 ug/mL

Another way to calculate this is to divide the original concentration by the dilution factor ( 5 in this case) elevated to the number of dilutions. In this case:

Concentration in the third tube = 20 ug/mL / 5³ = 0.16 ug/mL

To solve the equation pH = 4 + log(x) and find the value of x when the hydrogen ion concentration is 0.01 M, rearrange the equation by subtracting 4 from both sides. Substitute the value of pH with its equivalent -log(0.01) and simplify the equation. The value of x is 0.0001.

To solve the equation pH = 4 + log(x) and find the value of x when the hydrogen ion concentration is 0.01 M, we need to rearrange the equation. Subtracting 4 from both sides, we get log(x) = pH - 4. Using the fact that pH = -log[H+], we substitute the value of pH with its equivalent -log(0.01). Simplifying the equation, we have log(x) = -log(0.01) - 4. Taking the antilog (10^x) of both sides, we get x = 10^(-log(0.01) - 4). Evaluating this expression gives us x = 0.0001.

Answer:

Variability of data around the mean is best expressed through the standard deviation.

Explanation:

We have some statistical metrics, and we need to find the best measure of the variability of data around the mean.  

First variable is mode. Mode of a set of data values is the value that appears most often. It means the most frequent data.  

Second variable is Median. The median is a simple measure of central tendency. It is located around 50% of data range.  

Third variable is standard deviation. The standard deviation is found by taking the square root of the average of the squared deviations of the values subtracted from their average value. It means, it will show the dispersion of data around the average value.

According to the definition presents for the three variables, Standard deviation is the most appropriate measure of variability of data around the mean.  

Answer:

Correct answer is: Variability of data around the mean is best expressed through the standard deviation.

Explanation:

Got it correct on Plato Hope This helped :D

Answer:

The balanced equation for the complete oxidation reaction uses 2 moles of butane and 13 moles of Oxygen.

Explanation:

The oxidation of butane is shown in the following picture. As it is a complete combustion, the products of this reaction are carbon dioxide and water.

Butane (C₄H₁₀) combusts in the presence of oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O). The balanced reaction is: 2C₄H₁₀(g) + 13O₂(g) -> 8CO₂(g) + 10H₂O(g). This is a combustion reaction, which is exothermic and releases heat and light.

The question is asking for the balanced combustion reaction of butane, which is burned as a lighter fluid in disposable lighters. In the presence of sufficient oxygen, butane (C₄H₁₀) combusts to produce carbon dioxide (CO₂) and water (H₂O). The reaction can be represented and balanced as follows:

2C₄H₁₀(g) + 13O₂(g) -> 8CO₂(g) + 10H₂O(g)

This reaction is an example of a combustion reaction, where a hydrocarbon, like butane, burns in the air to produce carbon dioxide and water. It's also an exothermic reaction, releasing energy in the form of heat and light, which is what makes butane useful as a lighter fluid.

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Answer : The moles of oxygen gas lost are 2.88 mole

Explanation :

According to the Avogadro's Law, the volume is directly proportional to the number of moles of the gas at constant pressure and temperature.

[tex]V\propto n[/tex]   (At constant temperature and pressure)

or,

[tex]\frac{V_1}{V_2}=\frac{n_1}{n_2}[/tex]

where,

[tex]V_1[/tex] = initial volume of oxygen gas = 12.6 L

[tex]V_2[/tex] = final volume of oxygen gas = 12.1 L

[tex]n_1[/tex] = initial moles of oxygen gas = 3.0 mole

[tex]n_2[/tex] = final moles of oxygen gas = ?

Now put all the given values in the above formula, we get the final moles of oxygen gas.

[tex]\frac{12.6L}{12.1L}=\frac{3.0mole}{n_2}[/tex]

[tex]n_2=2.88mole[/tex]

Therefore, the moles of oxygen gas lost are 2.88 mole

1.Concentration of acetic acid is 89.99 mM. Concentration of sodium acetate is 160.0 mM . 2.0.180 moles of acetic acid. 0.32 moles of sodium acetate. 3. Mass of acetic acid in 2 L solution is 10.81 g. Mass of sodium acetate in 2 L solution is 26.25 g.

The amount of matter in an item is indicated by its mass, which is a fundamental physical attribute of matter. It is a scalar quantity that is typically measured in kilogrammes (kg) or grammes (g). Mass is separate from weight, which is the gravitational force exerted on an object and can change depending on the strength of the gravitational field.

1.pH = pKa + log [Sodium acetate] / [Acetic acid]

5.0 = 4.75 + log [Sodium acetate] / [Acetic acid]

log [Sodium acetate] / [Acetic acid] = 5.0 - 4.75

                                                          = 0.25

[Sodium acetate] = 1.778 x [Acetic acid]

[Sodium acetate] + [Acetic acid] = 250 mM

1.778 x [Acetic acid] +  [Acetic acid] = 250 mM

2.778 x [Acetic acid] = 250 mM

[Acetic acid] = 250 mM  / 2.778

                     = 89.99 mM

[Sodium acetate] = 1.778 x [Acetic acid]

                              = 1.778 x 89.99 mM

                              = 160.0 mM

2.Concentration of acetic acid = 89.99 mM

                                                  = 0.08999 M  

Concentration of sodium acetate = 160.0 mM

                                                      = 0.16 M

2 x 0.08999 = 0.180 moles of acetic acid.

2 x 0.16 = 0.32 moles of sodium acetate.

3.Mass of acetic acid = no of moles x molar mass

                                   = 0.180 mol x 60.05 g /mol

                                   = 10.81 g

Mass of sodium acetate = no of moles x molar mass

                                       = 0.32 mol x 82.03 g /mol

                                       = 26.25 g

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Final answer:

Using the Henderson-Hasselbalch equation, the concentrations of acetic acid and sodium acetate in the buffer solution are calculated to be approximately 89 mM and 161 mM, respectively. When considering a 2 L volume of this buffer, there would be approximately 0.178 moles of acetic acid and 0.322 moles of sodium acetate, which translates to 10.69 grams of acetic acid and 26.25 grams of sodium acetate.

Explanation:

To calculate the concentrations of acetic acid and sodium acetate in the buffer, we use the Henderson-Hasselbalch equation:
pH = pKa + log([A-]/[HA])

Given:

Let's calculate [A-] and [HA] (where [A-] is the concentration of sodium acetate and [HA] is the concentration of acetic acid):
5.0 = 4.75 + log([A-]/[HA])
=> log([A-]/[HA]) = 0.25
=> [A-]/[HA] = 10^0.25
=> [A-]/[HA] ≈ 1.78

Since [A-] + [HA] = 250 mM, we can set up a system of equations:
[A-] = 1.78[HA]
[A-] + [HA] = 250 mM

Solving for [HA] and [A-] gives us:
[HA] ≈ 89 mM
[A-] ≈ 161 mM

Next, we calculate the amount of acetic acid and sodium acetate in 2 L of the buffer:
amount of acetic acid = [HA] × 2 L = 0.089 mol/L × 2 L = 0.178 mol
amount of sodium acetate = [A-] × 2 L = 0.161 mol/L × 2 L = 0.322 mol

Finally, to calculate the mass of acetic acid and sodium acetate in 2 L of the buffer, we use their molar masses:
mass of acetic acid = 0.178 mol × 60.05 g/mol = 10.69 g
mass of sodium acetate = 0.322 mol × 82.03 g/mol = 26.25 g

Answer:

The final diameter of the balloon is 20.84 cm.

Explanation:

To answer this problem, because both the number of moles (because no air was lost or added to the balloon) and the pressure remain constant, we can use Charles' law, or the law of volumes:

V₁T₂=V₂T₁

Where V is Volume (in L) and T is temperature (in K). The subscripts 1 and 2 refer to different states of the gas: for this problem, let's say that ₁ refers to the state of the gas at 7:00 am and that ₂ refers to the state 6 hours later.

To calculate the volume occupied by the gas we use the formula for the volume of a sphere:

[tex]V=\frac{4}{3}*\pi  (\frac{d}{2})^{3}[/tex]

Thus the volume of the balloon at 7:00 am is 4188.79 cm³

Then we convert °F into K:

Now we use Charles' law to calculate V₂:

V₂=V₁T₂/T₁

V₂= [tex]\frac{4188.79cm^{3}*310.93K}{274.82 K}=4739.18cm^{3}[/tex]

Lastly we calculate the final diameter of the balloon:

[tex]4739.18cm^{3}=\frac{4}{3}*\pi  (\frac{d}{2})^{3}\\3554.38cm^{3}=\pi  (\frac{d}{2})^{3}\\1131.40cm^{3}=(\frac{d}{2})^{3}\\10.42cm=\frac{d}{2}\\20.84=d[/tex]

Answer:

5x10^3 L

Explanation:

Charle's Law states that the volume of a fixed amount of gas maintained at constant pressure is directly proportional to the absolute temperature of the gas, for a constant amount of gas we can write:

[tex]\frac{V1}{T1}=\frac{V2}{T2}[/tex]

As the pressure of the balloon doesn't change, we can use Charle's Law to solve the problem. Firs we change the given temperatures to absolute temperature units ( °K), using the following relations:

°K=273,15+°C

Therefore:

V1=4.6 x 10^3 L, T1=273,15+31=304,15°K

V2=?,                   T2=273,15+56=329,15°K

[tex]V2=\frac{V1T2}{T1}=\frac{4.6*10^3*329,15}{304,15}=4978,1L=5*10^3L[/tex]

The new volume of the balloon is 5x10^3 L.

The volume of a helium-filled balloon at 56°C under constant pressure can be calculated using Charles's Law by converting temperatures to Kelvins and using the volume-temperature direct proportionality relationship.

The subject of this question involves the relationship between volume and temperature of a gas under constant pressure, described by Charles's Law. This law states that the volume of an ideal gas is directly proportional to its temperature (in Kelvins) when pressure is held constant. To use Charles's Law for calculating the new volume of a balloon, first, convert the temperatures from Celsius to Kelvins (K = °C + 273.15). The initial temperature is 31°C, which is 304.15K, and the final temperature is 56°C, which is 329.15K.

Apply Charles's Law using the formula V1/T1 = V2/T2. Let V1 be the initial volume (4.6 x 10³ L), T1 be the initial temperature (304.15K), V2 be the final volume, and T2 be the final temperature (329.15K). Solving for V2 gives:

V2 = (V1 x T2) / T1 = (4.6 x 10³ L x 329.15K) / 304.15K

Calculating this will give us the new volume V2 which we express in scientific notation.

Answer:

The easiest way to make these solutions is preparing serial dilutions with dilution factor of 10.

Explanation:

In chemistry, a dilution is the way to reducing the concentration of a chemical adding more solvent.

To prepare the first 0,100 M NaCl from 1,00 M NaCl:

You must take an aliquot of 25,0 mL of 1,00 M NaCl and dilute until 250,0 mL.  Thus, the concentration will decrease ten times until the expected concentration. The dilution factor is 10.

To prepare the second 0,0100 M of NaCl:

From 0,100 M NaCl take an aliquot of 25 mL an dilute until 250,0 mL. Thus, the concentration will decrease ten times.

So, to prepare each solution you must take the last one and dilute it in a dilution factor of 10.

I hope it helps!

Answer : The final temperature will be, 292 K

Explanation :

In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.

[tex]q_1=-q_2[/tex]

[tex]m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)[/tex]

where,

[tex]c_1[/tex] = specific heat of ice = [tex]2.05J/g.K[/tex]

[tex]c_2[/tex] = specific heat of beer = [tex]4.2J/g.K[/tex]

[tex]m_1[/tex] = mass of ice = 50 g

[tex]m_2[/tex] = mass of beer = 450 g

[tex]T_f[/tex] = final temperature = ?

[tex]T_1[/tex] = initial temperature of ice = [tex]0^oC=273+0=273K[/tex]

[tex]T_2[/tex] = initial temperature of beer = [tex]20^oC=273+20=293K[/tex]

Now put all the given values in the above formula, we get:

[tex]50g\times 2.05J/g.K\times (T_f-273)K=-450g\times 4.2J/g.K\times (T_f-293)K[/tex]

[tex]T_f=291.971K\approx 292K[/tex]

Therefore, the final temperature will be, 292 K

Answer:

Quantum mechanical atomic model.

Explanation:

The first model of electronic configuration was given by Bohr's model.

The most accurate model of electronic configuration is the quantum mechanical atomic model.

Bohr's model has various limitations:

1. It does not explain the Zeeman effect and stark effect.

2. It is not valid for multi-electron system.

3. Heisenberg uncertainty principle is not followed by this model

The quantum mechanical atomic model explains all the four quantum numbers for the electronic configuration of an atom in the periodic table.

The quantum mechanical atomic model considered the Heisenberg uncertainty principle.

Answer:

Quantum mechanical atomic model.

Explanation:

The atom model given by quantum mechanics is the most modern, precise and complex, based on the mathematical form of the atomic structure.

Quantum theory states that matter has properties associated with waves, which is why the atom model was based on this theory. The so-called “Uncertainty Principle” states that the electron has no exact position in the electrosphere, no definite speed and direction. This is why the Bohr atom, with electrons spinning in circular orbits, is surpassed by the quantum model.

Answer:

The density of the metal is 21.675 g/mL.

The volume of metal with mass of 64.9 grams is 2.994 mL.

Explanation:

Density is defined as mass present in unit volume of the substance.

[tex]Density=\frac{Mass}{Volume}[/tex]

Mass of unknown metal = m = 427.0 g

Volume of the unknown metal = v = 19.7 mL

Density of the unknown metal = d

[tex]d=\frac{m}{v}=\frac{427.0 g}{19.7 mL}=21.675 g/mL[/tex]

Mass of the same unknown metal = M = 64.9 g

Volume of same unknown metal with mass M = V

Density of the metal  = d = 21.675 g/mL

[tex]21.675 g/ mL=\frac{64.9 g}{V}[/tex]

V = 2.994 mL

Answer: 20.1 kg.

Explanation:

To calculate mass of a substance, we use the equation:

[tex]\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}[/tex]

We are given:

Density of gasoline = [tex]0.737kg/L[/tex]

Volume of gasoline = [tex]7.2gallons=7.2\times 3.785L=27.252L[/tex]     (Conversion factor: [tex]1gal=3.785L[/tex] )

Putting values in above equation, we get:

[tex]0.737kg/L=\frac{\text{Mass of gasoline}}{27.252L}\\\\\text{Mass of gasoline}=20.084kg[/tex]

The rule apply for multiplication and division is :

The least precise number present after the decimal point determines the number of significant figures in the answer, thus the answer musty have three significant digits.

Hence, the mass added is 20.1 kg.

Answer:

27,397.23 L would be needed for a successful trip.

Explanation:

The problem gives us the density (ρ) of the fuel, by telling us that there are 803 g of fuel in 1 L, in which case:

ρ=[tex]\frac{mass}{Volume}=\frac{803g}{1L}  =803\frac{g}{L}[/tex]

The required mass of fuel is 2.2 * 10⁴ kg, we can convert this value into g:

2.2 * 10⁴ kg * [tex]\frac{1000g}{1kg}[/tex] = 2.2 * 10⁷ g

We calculate the required volume (V), using the mass and density:

[tex]803 g/L = \frac{2.2*10^{7}g }{V} \\V=\frac{2.2*10^{7}g }{803g/L}\\ V=27397.26 L[/tex]

Thus 27,397.23 L would be needed for a successful trip.

Explanation:

1 Pascal = 1 N/m²

To convert Pa to lbf/ft²

So, the conversion of N to pound force (lbf) is shown below as:

1 N = 0.224809 pound force (lbf)

The conversion of m² to ft² is shown below:

1 m² = 10.7639 ft²

So,

[tex]1\ Pa=\frac {1\ N}{1\ m^2}=\frac {0.224809\ lbf}{10.7639\ ft^2}

1 Pa = 0.02089 lbf / ft²

Hence proved.

Answer: The correct answer is Option  d.

Explanation:

To calculate the molarity of base, we use the equation given by neutralization reaction:

[tex]n_1M_1V_1=n_2M_2V_2[/tex]

where,

[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]H_2SO_4[/tex]

[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is KOH

We are given:

[tex]n_1=2\\M_1=0.543M\\V_1=72.1mL\\n_2=1\\M_2=?M\\V_2=39.0mL[/tex]

Putting values in above equation, we get:

[tex]2\times 0.543\times 72.1=1\times M_2\times 39.0\\\\M_2=2.01M[/tex]

Hence, the correct answer is Option d.

The concentration of the base is 2.01 M

A neutralization reaction is a reaction that occurs between an acid and a base to yield salt and water only;

This reaction occurs as follows; H2SO4 + 2KOH ----->K2SO4 + H2O

From the titration formula;

concentration of acid CA =  0.543 M

volume of acid VA = 72.1 mL

concentration of baseCB = ?

volume of base VB= 39.0 mL

Number of moles of acid = 1

Number of moles of base = 2

Given that;

CAVA/CBVB = NA/NB

CAVANB = CBVBNA

CB = 0.543 M * 72.1 mL * 2/39.0 mL * 1

CB = 2.01 M

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Answer:

The answer is 0.005097 mL.

Explanation:

Significant figures : The figures in a number which express the value of the magnitude of a quantity to a specific degree of an accuracy is known as significant digits.

Given :

[tex]x=\frac{(1.145 x 109 g/mol)\times (0.0035 mol)}{(8.57 x 10 g/mL)}[/tex]

[tex]x=\frac{0.4368 g}{8.57\times 10 g/mL}=0.005097053 mL[/tex]

[tex]x=0.005097053 mL\approx 0.005097 mL[/tex]

Answer:

b) Counter current

Explanation:

In mechanical, chemical, nuclear and other systems, it happens that heat must be transferred from one place to another or from one fluid to another. Heat exchangers are the devices that allow you to perform this task  the types of exchangers are presented  of heat as a function of flow: parallel flow; counterflow; cross flow.

Among the main reasons why exchangers are used

Heat are as follows:

• Heat a cold fluid using a fluid with a higher temperature.

• Reduce the temperature of a fluid by means of a fluid with a lower temperature.

• Bring the fluid to the boiling point using a fluid with a higher temperature.

• Condense a fluid in a gaseous state by means of a cold fluid

A backflow occurs when the two fluids flow in the same direction but in  opposite way. Each of the fluids enters the exchanger through different ends Since the fluid with less  temperature goes backflow from the heat exchanger at the end where the fluid enters with higher temperature,  the temperature of the coldest fluid will approach the temperature of the inlet fluid.

This type of exchanger  turns out to be more efficient than the other two types mentioned above. In contract with the exchanger  parallel flow heat, the counterflow exchanger may have the highest temperature in the cold fluid and the  lower temperature in the hot fluid after heat transfer in the exchanger.

Be careful with turbulent that it is not a type of exchanger but a system in which a fluid is found.

Answer:

a) Analyte: lead. Sample: paint.

b) Analyte: nitrate. Sample: soil.

c) Analyte: citric acid. Sample: Lime

1) Lead: Analyte.

2) Paint chips: Sample.

3) Soil: Sample.

4) Nitrate: Analyte.

5) Lime wedge: Sample.

6) Citric acid: Analyte.

Explanation:

A sample is a portion of material selected from a larger quantity of material while an analyte is the chemical of the system that will be analysed.

Thus:

a) Analyte is lead while you must take a sample of paint to analyze this lead.

b) Analyte is the nitrate while sample must be soil.

c) Analyte is citric acid and lime is the sample

1) Lead: Analyte.

2) Paint chips: Sample.

3) Soil: Sample.

4) Nitrate: Analyte.

5) Lime wedge: Sample.

6) Citric acid: Analyte.

Final answer:

In scenarios (a) to (c), the samples are paint chips, soil, and lime wedge, respectively, and the analytes are lead, nitrate, and citric acid, respectively. Item identifications are lead and nitrate as analytes, and paint chips, soil, and lime wedge as samples.

Explanation:

In analytical chemistry, the analyte is the substance whose chemical content is being measured or analyzed, and the sample is the material or product that contains the analyte. Here are the identifications for each scenario:

To clarify, here are the identifications for each item listed:

Answer: The molar solubility of carbon dioxide gas is 0.002 M

Explanation:

Henry's law states that the amount of gas dissolved or molar solubility of gas is directly proportional to the partial pressure of the liquid.

To calculate the molar solubility, we use the equation given by Henry's law, which is:

[tex]C_{CO_2}=K_H\times p_{liquid}[/tex]

where,

[tex]K_H[/tex] = Henry's constant = [tex]3.7\times 10^{-2}mol/L.atm[/tex]

[tex]p_{CO_2}[/tex] = partial pressure of carbonated drink = 0.51atm

Putting values in above equation, we get:

[tex]C_{CO_2}=3.7\times 10^{-2}mol/L.atm\times 0.51atm\\\\C_{CO_2}=1.887\times 10^{-2}mol/L=0.002M[/tex]

Hence, the molar solubility of carbon dioxide gas is 0.002 M

Answer:

0.019 mol/L

Explanation:

Given data

According to Henry's law, the solubility of a gas in a liquid is proportional to its partial pressure.

C = k × P

C = (3.7 × 10⁻² mol/L . atm) × 0.51 atm

C = 0.019 mol/L

Answer:

(a) 282 kJ

(b) 67.4 Calories

Explanation:

(a) The molar enthalpy, ΔH = −2802.5 kJ/mol, means that the heat produced by the reaction is 2802.5 kJ per mol of glucose.

We can multiply the enthalpy by the number of moles of glucose to get the heat produced by the metabolism. Grams of glucose will be converted to moles using the molar mass of glucose (180.156 g/mol):

(18.1 g)(mol/180.156g)(2802.5 kJ/mol) = 282 kJ

(b) Using the result we obtained above, kJ will be converted to Calories using the conversion factor of 4.184J = 1 cal. Calorie with a capital C is the same as a kilocalorie.

(282 kJ)(1 cal/4.184J) = 67.4 kcal = 67.4 Calories

Answer:

For a: The amount of heat produced for given amount of glucose is -283.05 kJ

For b: The amount of heat produced for given amount of glucose is -67648.9 Cal

Explanation:

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Given mass of glucose = 18.1 g

Molar mass of glucose = 180.16 g/mol

Putting values in above equation, we get:

[tex]\text{Moles of glucose}=\frac{18.1g}{180.16g/mol}=0.101mol[/tex]

The given chemical reaction follows:

[tex]C_6H_{12}O_6(s)+6O_2(g)\rightarrow 6CO_2(g)+6H_2O(l);\Delta H=-2802.5kJ/mol[/tex]

By Stoichiometry of the reaction:

When 1 mole of glucose is reacted, the amount of heat released is 2802.5 kJ

So, when 0.101 moles of glucose is reacted, the amount of heat released is [tex]\frac{2802.5}{1}\times 0.101=283.05kJ[/tex]

Hence, the amount of heat produced for given amount of glucose is -283.05 kJ

To convert the heat produced in kilo joules to calories, we use the conversion factor:

1 kJ = 239 Cal

So, [tex]-283.05kJ\times (\frac{239Cal}{1kJ})=-67648.9Cal[/tex]

Hence, the amount of heat produced for given amount of glucose is -67648.9 Cal