You need to prepare a solution with a specific concentration of Na+Na+ ions; however, someone used the end of the stock solution of NaClNaCl, and there isn’t any NaClNaCl to be found in the lab. You do, however, have some Na2SO4Na2SO4. Can you substitute the same number of grams of Na2SO4Na2SO4 for the NaClNaCl in a solution? Why or why not?

0.5 kg block of aluminum (caluminum=900J/kg⋅∘C) is heated to 200∘C. The block is then quickly placed in an insulated tub of cold water at 0∘C (cwater=4186J/kg⋅∘C) and sealed. At equilibrium, the temperature of the water and block are measured to be 20∘C.

If the original experiment is repeated with a 1.0 kg aluminum block, what is the final temperature of the water and block?

A. less than 20∘C

B. 20∘C

C. greater than 20∘C

Answer:

Option C is correct

Explanation:

Increase in the mass of aluminium block would increase the heat capacity of block isothermaly before immersed in water at 0° so heat available for transfer is higher so equilibrium temperature of system would increase.

Final answer:

The 1 g equivalents using the given prefixes are: mega−: 1 Mg, kilo−: 1 kg, deci−: 1 dg, centi−: 1 cg, milli−: 1 mg, micro−: 1 μg, nano−: 1 ng, pico−: 1 pg.

Explanation:

The 1 g equivalents using the given prefixes are as follows:

(a) mega−: 1 Mg (megagram)
(b) kilo−: 1 kg (kilogram)
(c) deci−: 1 dg (decigram)
(d) centi−: 1 cg (centigram)
(e) milli−: 1 mg (milligram)
(f) micro−: 1 μg (microgram)
(g) nano−: 1 ng (nanogram)
(h) pico−: 1 pg (picogram)

Answer:

The volume of water measured is 10mL

Explanation:

Given;

Mass of mass of beaker and the water = 23.670 g

Mass of empty beaker = 13.712 g

Then, mass of water only = Total mass of of beaker and the water minus Mass of empty beaker

mass of water only = 23.670 g - 13.712 g = 9.958 g

Density = mass/volume

Given density of water = 0.9982071 g/mL

Density of water = Mass of water/ Volume of water

Then, Volume of water =  Mass of water/Density of water

Volume of water = 9.958 g/0.9982071 g/mL

Volume of water = 9.975886 mL ≅ 10mL

Therefore, The volume of water measured is 10mL

Answer:

The bond angle between the p orbital is assumed to be 90 degrees But according to VSEPR theory, as molecular geometry is a little bit bent thus the angle is less than 109.5 degrees.

Explanation:

IN hydrogen sulfide, H_2 S, both hydrogen atoms consist of para-magnetic 1s orbital while sulfur consists of diamagnetic 3s and 2 para magnetic 3p orbital.

The bond angle between the p orbital is assumed to be 90 degrees But according to VSEPR theory, as molecular geometry is a little bit bent thus the angle is less than 109.5 degrees.

In hydrogen sulfide (H2S), the bonding is explained using valence bond theory. The bond angle in H2S is approximately 92 degrees.

In hydrogen sulfide (H2S), the bonding can be explained using valence bond theory. According to this theory, covalent bonds are formed by the overlap of atomic orbitals. In H2S, the sulfur atom forms a covalent bond with each hydrogen atom through overlap of its sp3 hybrid orbital and the hydrogen 1s orbital.

The predicted bond angle in H2S is approximately 92 degrees. This angle is less than the ideal tetrahedral angle of 109.5 degrees due to the presence of two lone pairs of electrons on the sulfur atom, which exert greater repulsion than the bonding pairs. This results in a distorted tetrahedral shape with a smaller bond angle.

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Explanation:

Molecular formula of the compound =

The carbon chain in the molecule will look like :

1. [tex]H_2C=CH-CH_2-CH_2-CH_2-OH[/tex]

2. [tex]H_3C-CH=CH-CH_2-CH_2-OH[/tex]

3. [tex]H_3C-CH-CH=CH-CH_2-OH[/tex]

4. [tex]H_3C-CH_2-CH_2-CH=CH-OH[/tex]

No branching is present, so that means the valency of the carbon will be fulfilled by 10 hydrogen atoms and 1 oxygen atom

Answer:

No. of Photons (red) = 7.05 No. of Photons

No. of Photons (blue) = 4.78 No. of Photons

Explanation:

v (red) = 3 x 108/700 x 10-9 = 4.28 x 10 power 15 Hz

v (blue) = 3 x 108/475 x 10-9 = 6.31 x 10 power 15 Hz

(a) No. of Photons (red) = E/hv = 2.0 x 10 power -17 / 6.626 x 10 power -34 x 4.28 x 10 power 15

No. of Photons (red) = 7.05 No. of Photons

(b) No. of Photons (blue) = E/hv = 2.0 x 10 power -17 / 6.626 x 10 power -34 x 6.31 x 10 power 15

No. of Photons (blue) = 4.78 No. of Photons

Answer:

Mass of 22-Na contained in the sample = 0.0599 g

Explanation:

Mass of the isotope mixture = 1.8385g

Isotope mixture has apparent mass of 22.9573 u

23-Na has a relative atomic mass of 22.9898 u

22-Na has a relative atomic mass of 21.9944 u

Let the relative abundance of 23-Na be X

Then the relative abundance of 22-Na would be (1-X)

21.9944 (1-X) + 22.9898 X = 22.9573

21.9944 - 21.9944X + 22.9898X = 22.9573

22.9898X - 21.9944X = 22.9573 - 21.9944

0.9954X = 0.9639

X = 0.9674

Relative abundance of 23-Na = 0.9674

Relative abundance of 22-Na = 1 - 0.9674 = 0.0326

Mass of 22-Na in the 1.8385g of sample is

Relative abundance of 22-Na × Mass of sample = 0.0326 × 1.8385g = 0.0599 g

Answer:

0.2544 moles of water were removed from the sample by the heating process.

Explanation:

Mass of empty evaporating dish = 9.687 g

Mass of evaporating dish and sample of hydrate = 18.407 g

Mass of hydrate  = 18.407 g - 9.687 g = 8.72 g

Mass of the evaporating dish and hydrate after heating = 14.007 g

14.007 g = mass of dish + mass of dehydrate

Mass of dehydrate = 14.007 g - 9.867 g = 4.14 g

Mass of water evaporated = hydrated sample - dehydrated sample

= 8.72 g - 4.14 g = 4.58 g

Moles of water evaporated :

[tex]\frac{4.58 g}{18 g/mol}=0.2544 mol[/tex]

0.2544 moles of water were removed from the sample by the heating process.

The mass of the water removed from the sample by the heating process is determined by subtracting the mass of the evaporating dish and sample after heating from before heating. This mass is then divided by the molar mass of water (18.015 g/mol) to calculate the number of moles of water removed.

To calculate the moles of water removed from the sample by the heating process, first we have to determine the mass of the water removed. This would be equal to the mass of the evaporating dish and sample of hydrate before heating minus the mass after heating, i.e., 18.407 g - 14.007 g = 4.4 g.

Then, we calculate the number of moles, using the molar mass of water as a conversion factor from mass to moles. The molar mass of water is 18.015 g/mol. Therefore, the number of moles of water removed would be 4.4 g / 18.015 g/mol = 0.244 mol.

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Answer:

The molarity of the new solution is 0.72 M

Explanation:

Step 1: Data given

Volume of the original solution = 360 mL =.360 L

Molarity = 0.87 M

We add 75 mL = 0.075 L

Step 2: Calculate moles

Moles = molarity * volume

Moles = 0.87 M * 0.360 L

Moles = 0.3132 moles

Step 3: Calculate new molarity

The number of moles stays constant

Molarity = moles / volume

Molarity = 0.3132 moles / (0.36+0.075)

Molarity = 0.3132 moles / 0.435 L

Molarity = 0.72 M

The molarity of the new solution is 0.72 M

To determine the molarity of the new solution, calculate the amount of acetic acid remaining after dilution and then use the formula Molarity = Moles / Volume.

To determine the molarity of the new solution, we need to calculate the amount of acetic acid that remains in the solution after adding water. The number of moles of acetic acid before dilution can be determined using the formula:

Moles = Concentration x Volume

Next, we need to calculate the final volume of the solution by adding the volume of water (75 mL) to the initial volume of the acetic acid solution (360 mL). Using this final volume and the number of moles of acetic acid, we can determine the molarity of the new solution using the formula:

Molarity = Moles / Volume

Substituting the values into the equation, the molarity can be calculated.

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The reaction of 19.3 g of aluminum with 63.2 g of ferric oxide is exothermic, releasing 2395.25 kJ of heat. Aluminum is the limiting reagent in the reaction.

The limiting reagent is the reactant that is used up completely in the reaction. To determine the limiting reagent, compare the ratio of the moles of each reactant to the stoichiometric coefficients in the balanced chemical equation. The reactant with the smaller ratio is the limiting reagent.

1: Calculate the number of moles of each reactant.

Moles of aluminum = 19.3 g / 27 g/mol = 0.715 mol

Moles of ferric oxide = 63.2 g / 231.5 g/mol = 0.272 mol

2: Determine the limiting reagent.

The ratio of moles of aluminum to moles of ferric oxide is 0.715 mol / 0.272 mol = 2.63. The stoichiometric ratio of aluminum to ferric oxide in the balanced chemical equation is 8:3. Since 2.63 is less than 8/3, aluminum is the limiting reagent.

3: Calculate the amount of heat released.

q = -3350 kJ/mol * 0.715 mol = -2395.25 kJ

4: Interpret the answer.

The amount of heat released is -2395.25 kJ. This means that the reaction releases 2395.25 kJ of heat.

The amount of heat released by the reaction of 19.3 g of Al with 63.2 g of Fe_3O_4 is -2395.25 kJ.

Answer:

1. Density = 1.96g/L

2. Molar Mass of the gas = 42.61g/mol

Explanation:

1. Mass = 2.25g

Volume = 1.15L

Density = Mass /volume = 2.25/1.15 = 1.96g/L

2. V = 1.15L

P 1.10atm

R = 0.082atm.L/mol /K

T = 63°C = 63 + 273 = 336K

n =?

PV = nRT

n = PV/RT = ( 1.1 x 1.15)/(0.082 x 336)

n = 0.046mol

Mass = 1.96g

n = Mass /Molar Mass

Molar Mass = Mass / n = 1.96/0.046

Molar Mass = 42.61g/mol

Answer:

16.5 g

Explanation:

When a nonvolatile compound is dissolved in a pure solvent, the freezing point of the solvent is reduced, because the interaction solvent-solute requires more energy to be joined, and so, it freezes. This property is called cryoscopy, and the temperature change (ΔT) can be calculated by:

ΔT = Kc*W*i

Where Kc is the cryoscopy constant of the solute X, W is the molality of the solution, and i is the van't Hoff factor, which determines the percent of the solute that is dissolved. For organic molecules, such as alanine, i = 1.

The molality is the number of moles of the solute divided by the mass (in kg) of the solvent (1200 g = 1.2 kg). The molar mass of alanine is 89.09 g/mol, and the number of moles of it is the mass divided by the molar mass:

n = 45.8/89.09

n = 0.5141 mol

W = 0.5141/1.2 = 0.4284 mol/kg

So, Kc of X is:

4.10 = Kc*0.4284*1

Kc = 9.57 °C.kg/mol

So, if now sodium chloride is added to X, and the variation temperature is the same, and i = 1.82:

4.10 = 9.57*W*1.82

W = 0.2354 mol/kg

The number of moles of the solute is then:

W = n/1.2

0.2354 = n/1.2

n = 0.2825 mol

The molar mass of sodium chloride is 58.44 g/mol, thus the mass is the molar mass multiplied by the number of moles:

m = 58.44*0.2825

m = 16.5 g

Water is able to absorb large amounts of energy and heat because of large amounts of hydrogen bonds between the hydrogen of one water molecule and the oxygen of another water molecule. So the correct option is D.

Heat capacity is the ability of a molecule to absorb heat energy. Hydrogen bonds between water molecules are what give water its remarkable thermal conductivity. Hydrogen bonds are disrupted and water molecules may move freely when heat is absorbed.

Hydrogen bonds are created and release a significant quantity of energy as the temperature of water drops. Of all liquids, water has the largest specific heat capacity. The amount of heat that one gram of a substance needs either absorb or lose in order to change its temperature by one degree Celsius is known as specific heat.

This equates to one calorie, or 4.184 Joules, for water. Water, therefore, takes a very long time to heat up and chill down. In actuality, water has a specific heat capacity that is nearly five times more than sand. This explains why land cools more quickly than oceans.

Water is a great habitat because of its resilience to abrupt temperature changes, which enables organisms to exist without being subjected to significant temperature fluctuations. Furthermore, because water makes up the majority of many species, having a large heat capacity enables highly controlled interior body temperatures.

Therefore the correct option is D.

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Answer:

Explanation:

PFR - Plug Flow Rate

The steps and detailed integration and appropriate substitution is as shown in the attached file.

The fractional conversion of chemical A in the PFR under the given conditions is approximately 1, indicating that the conversion is almost complete.

The question pertains to the calculation of the fractional conversion of a reactant, A, in a Plug Flow Reactor (PFR). According to the given conditions, we know that the rate equation is -rA = kCa and the value of k is 45 h⁻¹. Given that the volume of the reactor is 1000 L and the molar flowrate of A is 500 mol/h, we can calculate the residence time τ as V/F = 1000 L / 500 mol/h = 2h.

For a first order irreversible reaction in a PFR, the conversion, X, is given by X = 1 - exp(-k*τ). Plugging in the given value of k and the calculated value of τ, we find that X = 1 - exp(-45 h⁻¹ * 2 h) which gives X approximately equal to 1. Hence, the fractional conversion of A is almost complete.

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To find the molality of the silver nitrate solution, we can use the mass percent and density of the solution. The molality is found to be 2.99 mol/kg.

To find the molality of the silver nitrate solution, we need to first determine the moles of silver nitrate in the solution. We can use the mass percent and density to do this.

First, let's assume we have 100 g of the solution.

This means we have 36 g of silver nitrate in the solution (since it is 36% by mass).

The molar mass of AgNO3 is 169.88 g/mol, so we can convert the mass of the silver nitrate to moles: 36 g / 169.88 g/mol = 0.2124 mol.

The density of the solution is given as 1.41 g/mL, so 100 g of the solution would have a volume of 100 g / 1.41 g/mL = 70.92 mL.

Now, we can calculate the molality using the moles of AgNO3 and the mass of the water:

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

Molality = 0.2124 mol / 0.07092 kg

= 2.99 mol/kg

Answer:

-35,281.5 J

Explanation:

To convert the gaseous ethanol to liquid ethanol, three steps will occur. First, it will lose heat and the temperature will decrease until its boiling point, so from 300.0°C to 78.5°C. Thus, more heat will be lost, but now, with the temperature constant, so the gas will be converted to liquid. And then, the liquid will lose heat to decrease the temperature from 78.5°C to 25.0°C.

The total heat loss is the sum of the heats of each step. Because the heat is being removed from the system, it's negative. The first and last step occurs with a change in temperature, and so the heat is calculated by:

Q = m*c*ΔT

Where m is the mass, c is the specific heat of the gas (first step) or liquid (last step), and ΔT the temperature variation (final - initial). The mass of ethanol is the molar mass 46.07 g/mol multiplied by the number of moles, so:

m = 46.07 * 0.304 = 14.00 g

The second step occurs without a change in temperature, and the heat is then:

Q = -n*ΔH°vap

Where n is the number of moles, ΔH°vap is the heat of vaporization, and the minus signal indicates that the heat is being lost. Then, the heat of each step is:

Q1 = 14.00*1.43*(78.5 - 300,0) = -4434.43 J

Q2 = -0.304*40.5 = -12.312 kJ = -12312 J

Q3 = 14.00*2.45*(25.0 - 78.5) = -1835.05 J

Q = Q1 + Q2 + Q3

Q = -35,281.5 J

Explanation:

San Antonio's climate is more humid than Galveston. More water in the air has more specific heat

capacity i.e. humid air retains more heat at energy. So San Antonio is warmer than Galveston in summer.

San Antonio has far more heat hot springs that elevate the temperature, San Antonio's

humidity is higher, water in the air absorbs heat and makes people feel hotter.

Final answer:

Water has higher specific heat than other materials, which leads to higher summer temperatures in San Antonio compared to Galveston due to the molecular properties of water.

Explanation:

Water has higher specific heat than other materials, which means it absorbs or releases more heat for the same change in temperature. The temperature in San Antonio is hotter in the summer than in Galveston because of the molecular properties of water. The bodies of water surrounding San Antonio, such as rivers or lakes, have a larger heat capacity compared to the ocean surrounding Galveston. This means that it takes more energy to raise the temperature of the bodies of water in San Antonio, resulting in higher summer temperatures.

Answer:

3.9

Explanation:

Let's consider the following reaction at equilibrium.

CO(g) + Cl₂(g) ↔ COCl₂(g)

We can find the pressures at equilibrium using an ICE chart.

       CO(g) + Cl₂(g) ↔ COCl₂(g)

I       0.96       1.15            0

C        -x           -x            +x

E    0.96-x    1.15-x           x

The sum of the partial pressures is equal to the total pressure.

pCO + pCl₂ + pCOCl₂ = 1.47

(0.96-x) + (1.15-x) + x = 1.47

2.11 - x = 1.47

x = 0.64

The pressures at equilibrium are:

pCO = 0.96 - x = 0.32 atm

pCl₂ = 1.15 - x = 0.51 atm

pCOCl₂ = x = 0.64 atm

The pressure equilibrium constant (Kp) is:

Kp = pCOCl₂ / pCO × pCl₂

Kp = 0.64 / 0.32 × 0.51

Kp = 3.9

Final answer:

The equilibrium constant, Kp, for the formation of phosgene from carbon monoxide and chlorine is calculated to be 2.94 atm⁻¹.

Explanation:

In this reaction, the formation of phosgene from carbon monoxide and chlorine is represented as:

CO(g) + Cl₂(g) → COCl₂(g)

The equilibrium constant, Kp, can be calculated using the changes in pressures of the reactants and products at equilibrium:

Change in pressure for CO: -0.46 atm

Change in pressure for Cl2: -0.15 atm

Pressure of CO at equilibrium: 0.50 atm

Pressure of Cl₂ at equilibrium: 1.00 atm

Therefore, the expression for Kp would be: Kp = (PCOCl₂) / (PCO × PCl₂) = (1.47) / (0.50 × 1.00) = 2.94 atm⁻¹

Final answer:

To find the concentration of the Ba(OH)₂ solution that neutralizes HCOOH, calculate the moles of HCOOH used and apply these to the volume of Ba(OH)₂ solution. The concentration is found to be 2.157 M.

Explanation:

The question asks about calculating the concentration of a Ba(OH)₂ solution used to neutralize a known volume and concentration of HCOOH. The balanced chemical equation for the reaction between formic acid (HCOOH) and barium hydroxide (Ba(OH)₂) is:

HCOOH + Ba(OH)₂ → BaCO₃ + 2H₂O

First, calculate the moles of HCOOH used in the titration:

Therefore, the concentration of the Ba(OH)₂ solution is 2.157 M.

The concentration of the [tex]Ba(OH)\(_2\)[/tex]solution is approximately 1.078 M, when rounded to four decimal places.

To find the concentration of the [tex]Ba(OH)\(_2\)[/tex] solution, we need to use the concept of molarity and the stoichiometry of the neutralization reaction. The balanced chemical equation for the reaction between formic acid (HCOOH) and barium hydroxide [tex](Ba(OH)\(_2\))[/tex] is:

[tex]\[ 2HCOOH + Ba(OH)_2 \rightarrow Ba(HCOO)_2 + 2H_2O \][/tex]

From the equation, we see that 2 moles of HCOOH react with 1 mole of [tex]Ba(OH)\(_2\).[/tex]

First, we calculate the number of moles of HCOOH that reacted:

[tex][ \text{moles of HCOOH} = \text{volume of HCOOH} \times \text{concentration of HCOOH} \][/tex]

[tex]\[ \text{moles of HCOOH} = 31.4 \text{ mL} \times \frac{1 \text{ L}}{1000 \text{ mL}} \times 1.120 \text{ M} \][/tex]

[tex]\[ \text{moles of HCOOH} = 0.0314 \text{ L} \times 1.120 \text{ M} \][/tex]

[tex]\[ \text{moles of HCOOH} = 0.035128 \text{ moles} \][/tex]

Now, using the stoichiometry of the reaction (2 moles of HCOOH to 1 mole of [tex]Ba(OH)\(_2\)[/tex] we find the moles of [tex]Ba(OH)\(_2\)[/tex] that reacted:

[tex]\[ \text{moles of Ba(OH)}_2 = \frac{1}{2} \times \text{moles of HCOOH} \][/tex]

[tex]\[ \text{moles of Ba(OH)}_2 = \frac{1}{2} \times 0.035128 \text{ moles} \][/tex]

[tex]\[ \text{moles of Ba(OH)}_2 = 0.017564 \text{ moles} \][/tex]

Next, we calculate the concentration of [tex]Ba(OH)\(_2\)[/tex] using the definition of molarity:

[tex]\[ \text{concentration of Ba(OH)}_2 = \frac{\text{moles of Ba(OH)}_2}{\text{volume of Ba(OH)}_2 \text{ solution in liters}} \][/tex]

[tex]\[ \text{concentration of Ba(OH)}_2 = \frac{0.017564 \text{ moles}}{16.3 \text{ mL} \times \frac{1 \text{ L}}{1000 \text{ mL}}} \][/tex]

[tex]\[ \text{concentration of Ba(OH)}_2 = \frac{0.017564 \text{ moles}}{0.0163 \text{ L}} \][/tex]

[tex]\[ \text{concentration of Ba(OH)}_2 = 1.0775 \text{ M} \][/tex]

Therefore, the concentration of the [tex]Ba(OH)\(_2\)[/tex]solution is approximately 1.078 M, when rounded to four decimal places.

The correct answer is: [tex]\[ \boxed{1.078 \text{ M}} \][/tex]

Answer:

Answer in explanation

Explanation:

a. Carbon, atomic number 6

Helium has 2 electrons. We add this to the other 4 to make 6

Other group elements: Silicon Si, Germanium Ge , Tin Sn , lead Pb , Flerovium Fl

b. Vanadium, atomic number 23

Argon has 18 electrons, we add 5 to the 18 to make 23

Other group members are: Niobium Nb, Tantalum Ta , Dubnium Db

c. Phosphorus, atomic number 15

Neon has atomic number of 10

Other group members are: Nitrogen N , Phosphorus P , Arsenic As , Antimony Sb , Bismuth Bi and Moscovium Mc

The structure of  the bromite ion , obeying the octet rule is attached below.

An ion is defined as an atom or a molecule which has a net electrical charge. There are 2 types of ions :1) cation 2) anion . The cation is the positively charged ion and anion is the negatively charged ion . As they are oppositely charged they attract each resulting in the formation of ionic bond.

Ions consisting of single atom are mono-atomic ions while which consists of two or more ions are called as poly-atomic ions . They are created by chemical interactions . They are very reactive in their gaseous state and rapidly react with oppositely charged ions resulting in neutral molecules.

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In the given gases, HF should have the largest van der Waals constant a because of its stronger intermolecular forces, and Cl2 should have the largest van der Waals constant b due to its larger molecular size.

The van der Waals constants (a) and (b) are indicative of the strength of the forces between molecules, and the physical size of the molecules in a given gas, respectively.

(a) In the selection of H2, HF, F2, we would expect the molecule with the strongest intermolecular forces to have the largest van der Waals constant a. That would be HF because when comparing these gases, HF has permanent dipole-dipole interaction which is stronger than the London dispersion forces in H2 and F2.

(b) For the gases H2, HCl, Cl2, we would expect the molecule with the largest physical size to have the largest van der Waals constant b. In this case, Cl2 is the largest molecule and thus would have the largest van der Waals constant b under normal conditions.

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Answer:

1.13 M

Explanation:

Given data

The molarity of the stock solution of luminol is:

M = mass of solute / molar mass of solute × liters of solution

M = 15.0 g / 177.16 g/mol × 0.0750 L

M = 1.13 M

To calculate the molarity of the stock solution of luminol, convert the mass of luminol to moles, convert the volume of the solution to liters, and divide the moles by the volume. The molarity is found to be 1.13 M.

The question concerns the calculation of the molarity of a stock solution of luminol. To determine the molarity, you need the amount of solute in moles and the volume of solution in liters. First, calculate the number of moles of luminol by dividing the weight (15.0 g) by the molar mass of luminol (177.16 g/mol). Then, convert the volume of the solution from milliliters to liters by dividing by 1000. Finally, divide the number of moles of luminol by the volume of the solution in liters to find the molarity.

Here's the calculation in detail:

Therefore, the molarity of the stock solution of luminol is 1.13 moles per liter, or 1.13 M.

Answer:

73140 kJ.

Explanation:

Equation of the hydrogenation reaction:

C2H4 + H2 --> C2H6

Molar mass = (2*12) + (6*1)

= 30 g/mol

Mass of C2H4 = 15.9 kg

= 15900 g

Number of moles = mass/molar mass

= 15900/30

= 530 mol of C2H6

By stoichiometry, 1 mole of C2H4 is hydrogenated to give 1 mole of C2H6

Number of moles of C2H4 = 530 mole

Q = n * q

= 530 * 138 kJ

= 73140 kJ.

Final answer:

To calculate the total heat released when 15.9 kg of ethane (C₂H₆) is formed, we convert the mass of C₂H₆ to moles and multiply by the heat released per mole of ethene (C₂H₄). The total heat released is 73015 kJ.

Explanation:

The student is asking about the heat released during a hydrogenation reaction where ethene (C₂H₄) and hydrogen gas (H2) are converted into ethane (C₂H₆). The reaction is exothermic, meaning that heat is released when it occurs. Given that 138 kJ is released per mole of C₂H₄ reacting, to find the total heat released when 15.9 kg of C₂H₆ is formed, we need to follow these steps:

Here's the calculation:

Therefore, the total heat released when 15.9 kg of ethane is formed is 73015 kJ (to zero decimal places).

Answer:

5.9 x 10^-9 N.

Explanation:

Below is an attachment containing the solution.

The force of attraction between a Ca2+ and an O2- ion can be calculated using Coulomb's Law. Coulomb's Law states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

The force of attraction between a Ca2+ and an O2- ion can be calculated using Coulomb's Law. Coulomb's Law states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. The equation is given as:

[tex]F = (k * q1 * q2) / r^2[/tex]

Where F is the force of attraction, k is the proportionality constant[tex](2.31 × 10^16 J pm),[/tex] q1 and q2 are the charges of the ions, and r is the distance between their centers.

In this case, Ca2+ has a charge of +2 and O2- has a charge of -2. The distance between their centers is 1.25 nm, which is equivalent to 1250 pm. Plugging in the values:

[tex]F = (2.31 × 10^16 J pm * 2 * -2) / (1250 pm)^2[/tex]

Simplifying the equation:

[tex]F = -1.48 x 10^10 N[/tex]

Therefore, the force of attraction between the Ca2+ and O2- ions is[tex]-1.48 x 10^10 N (attractive force).[/tex]

Answer:

To synthesize cis-2-methylcyclopentyl from methycyclopentanol, you need to replace the acetate hydroxyl group with acetate by inverting the configuration.  

Explanation:

To understand the process, you need to understand the nucleophilic mechanism taking place in the process. This is the first stage of the process. Hydroxide is a poor leaving group, to it must be converted to a good leaving group. To effect the change, it is necessary to use p-toluenesuphate.

p-toluenesuphate is favored because this can be prepared by a reaction that alters none of the bonds attached to the stereogenic center.

The reaction of p-toluensulfonate with potassium acetate in acetic acid effects the conversion to give the final product: cis-2-methylcyclopentyl.  

Final answer:

The question involves synthesizing cis-2-methylcyclopentyl acetate from trans-2-methylcyclopentanol, requiring a reaction sequence that includes the use of a tosylate intermediate and control of the stereochemistry to retain the cis configuration.

Explanation:

The question asks how to synthesize cis-2-methylcyclopentyl acetate from trans-2-methylcyclopentanol. To achieve the transformation from trans to cis stereochemistry, one might need to carry out a series of reactions, including esterification and the use of a tosylate intermediate to facilitate inversion of stereocenter or through other stereospecific mechanisms. An appropriate synthetic route could potentially involve the protection of hydroxyl group, formation of the tosylate, followed by a nucleophilic substitution that inverts the stereochemistry, and concluding with the esterification to yield the desired acetate.

It is important to note that the 'tosylate intermediate' is a common intermediate in organic synthesis allowing for an alcohol to be converted into a better leaving group for subsequent substitution reactions. Stereoselectivity is crucial as the goal is to preserve the cis stereochemistry in the final product.

Answer:

The relation between the shielding and effective nuclear charge is given as

[tex]Z_{eff} = Z -S[/tex]

where s denote shielding

z_{eff} denote effective nuclear charge

Z - atomic number

Explanation:

shielding is referred to as the repulsion of an outermost electron to the pull of electron from valence shell.  Higher the electron in valence shell higher will be the shielding effects.  

Effective nuclear charge is the amount of net positive charge that valence electron has.

The relation between the shielding and the effective nuclear charge is given as  

[tex]Z_{eff} = Z -S[/tex]

wheres denote shielding

z_{eff} denote effective nuclear charge  

Z - atomic number

Answer: The molality of perchloric acid in the solution is 14.95 m

Explanation:

We are given:

Molarity of perchloric acid solution = 9.2 M

This means that 9.2 moles of perchloric acid are contained in 1 L or 1000 mL of solution

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

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

Moles of perchloric acid = 9.2 moles

Molar mass of perchloric acid = 100.5 g/mol

Putting values in above equation, we get:

[tex]9.2mol=\frac{\text{Mass of perchloric acid}}{100.5g/mol}\\\\\text{Mass of perchloric acid}=(9.2mol\times 100.5g/mol)=924.6g[/tex]

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]

Density of solution = 1.54 g/mL

Volume of solution = 1 L = 1000 mL

Putting values in above equation, we get:

[tex]1.54 g/mL=\frac{\text{Mass of solution}}{1000mL}\\\\\text{Mass of solution}=(1.54g/mL\times 1000mL)=1540g[/tex]

We are given:

Mass of solute (perchloric acid) = 924.6 grams

Mass of solution = 1540 grams

Mass of solvent = Mass of solution - mass of solute = [1540 - 924.6] g = 615.4 g

To calculate the molality of solution, we use the equation:

[tex]\text{Molality}=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}[/tex]

Where,

[tex]m_{solute}[/tex] = Given mass of solute (perchloric acid) = 924.6 g

[tex]M_{solute}[/tex] = Molar mass of solute (perchloric acid) = 100.5 g/mol

[tex]W_{solvent}[/tex] = Mass of solvent = 615.4 g

Putting values in above equation, we get:

[tex]\text{Molality of perchloric acid}=\frac{924.6\times 1000}{100.5\times 615.4}\\\\\text{Molality of perchloric acid}=14.95m[/tex]

Hence, the molality of perchloric acid in the solution is 14.95 m

Considering the definition of molality, the molality of a 9.2 M solution of perchloric acid is  14.95 [tex]\frac{moles}{kg}[/tex].

Molality is a measure of concentration that is defined as the ratio of the number of moles of any dissolved solute to kilograms of solvent.

The Molality of a solution is determined by the expression:

[tex]Molality=\frac{number of moles of solute}{kilograms of solvent}[/tex]

Molality is expressed in units [tex]\frac{moles}{kg}[/tex].

Being the molarity is the number of moles of solute that are dissolved in a certain volume a molarity of 9.2 M means that 9.2 moles of perchloric acid are contained in 1 L or 1000 mL of solution.

Then, the number of moles of solute is 9.2 moles of perchloric acid.

In first place, density is the ratio of the weight (mass) of a substance to the volume it occupies. So, a density of 1.54 [tex]\frac{g}{mL}[/tex]means that you have 1.54 grams per 1 mL of solution or 1540 grams per 1 L (1000 mL) of solution. So, the mass of solution is 1540 grams in 1 L of solution

The mass of solution is the sum between the mass of solute and the mass of solvent.

Being the moles of perchloric acid 9.2 moles and the molar mass of perchloric acid 100.5 [tex]\frac{g}{mole}[/tex], the mass of the solute perchloric acid is calculated as:

mass of solute= number of moles of solute× molar mass

mass of solute= 9.2 moles× 100.5 [tex]\frac{g}{mole}[/tex]

mass of solute= 924.6 grams

Considering 1 L of solution, then, the mass of solvent is calculated as:

mass of solution= mass of solute +the mass of solvent

1540 grams = 924.6 grams +the mass of solvent

1540 grams - 924.6 grams= mass of solvent

615.4 grams= 0.6154 kg= mass of solvent

Finally, the mass of solvent is 0.6154 kg.

So, being the number of moles of solute 9.2 moles and mass of solvent 0.6154 kg, the molality is calculated as:

[tex]Molality=\frac{9.2 moles}{0.6154 kg}[/tex]

Molality= 14.95 [tex]\frac{moles}{kg}[/tex]

Finally, the molality of a 9.2 M solution of perchloric acid is  14.95 [tex]\frac{moles}{kg}[/tex].

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Answer:

Melting of snow

Evaporation of water from desk

Explanation:

Processes that increase the entropy of the universe are those processes that have an increased disorderliness. We should note that there are three principal states of matter which are the liquid, gas and solid. The gaseous state is the most disorderly while the solid is the least disorderly.

Now. We can see that the cooling of a hot cup of coffee is a process that needs or leads to a loss in temperature which obviously decreases disorderliness of the universe.

The melting of snow however is a process that leads to an increase in the disorderliness of the universe. It entails moving from the solid state to the liquid state. It tends to move to a more disordered state indicating an increase in the entropy of the universe.

The evaporation of water from the desk is quite similar to that above. Hence since we are moving from the liquid to the gaseous state via evaporation, we can state that the entropy of the universe has increased since we have moved from a state with a lesser degree of disorderliness to a state that is more disordered I.e from liquid to gaseous state.

The processes that result in the increase in entropy of the universe would be the melting of snow above 0 °C and the evaporation of water from a desk at room temperature.

Entropy refers to the degree of disorderliness of a system. The degree of disorderliness increases when the temperature of a system increases or when there is a phase change in the order solid > liquid > gas.

Thus, when snow melts, a phase change occurs from solid to liquid leading to an increase in entropy. Also. when water evaporates from a desk, it changes phase from liquid to gas and thereby leads to an increase in entropy.

More on entropy can be found here: https://brainly.com/question/22655760

Answer:

5650 g/mol

Explanation:

The osmotic pressure (π) is the pressure needed to prevent that the osmose occur in a system. Osmose is the process that a solvent goes through a membrane where the solution is more concentrated.

This property can be calculated by:

π = M*R*T

Where M is the molarity of the solution (mol/L), R is the ideal gas gas constant (62.3 torr.L/mol.K), and T is the temperature (25°C = 298 K), so:

23 = M*62.3*298

M = 1.24x10⁻³ mol/L

So, if the concentration is mass is 7.0 g/L, the molar mass (MM) of the sugar is its concentration is mass divided by the molarity:

MM = 7/1.24x10⁻³

MM = 5650 g/mol

5650 g/mole is the molar mass of the given sugar, whose osmotic pressure of solution is is the molar mass of this sugar.

It is that pressure which is applied on the solution to stop the flow of pure solvent from low concentration to high concentration through semipermeable membrane, and it is calculated as follow:

π = CRT, where

π = osmotic pressure = 23 torr (given)

C= concentration = to find?

R =  ideal gas gas constant = 62.3 torr.L/mol.K

T = temperature = 25 degree C = 298 K

Putting all these value in the above equation, we get

23 = C × 62.3 × 298

C = 1.24x10⁻³ mol/L

Here the concentration is given in the form of molarity, which defines as no. of moles of solute present in per liter of solvent. And no. of moles is calculated as :

n = W/M, where

W = given mass = 7.0 g (given)

M = molar mass = to find?

n = no. of moles = 1.24x10⁻³ mol/L (calculated above)

Putting all values in above equation we get,

M = 7/1.24x10⁻³ = 5650 g/mol.

Hence, 5650 g/mol is the molar mass of this given sugar.

To learn more about osmotic pressure, visit the below link:

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