One of the students in lab decided to use two fractionating columns (one on top of the other) instead of just one. How would this:_________.
a) affect the separation between hexane and heptane?
b) affect the yield of recovered pure hexane?
c) affect the yield of recovered pure heptane.
Explain your reasoning.

Answer:

[tex]pH=4.77[/tex]

Explanation:

From the question we are told that:

pKa for Acetic Acid [tex]pK_a= 4.77[/tex]

Therefore

For Equal Concentration of acetic acid and acetatic ion

[tex]CH_3COOH=CH_3COO^-[/tex]

Generally the Henderson's equation for pH value is mathematically given by

[tex]pH=pK_a+log\frac{base}{acid}[/tex]

[tex]pH=4.77+log\frac{CH_3COO^-}{CH_3COOH}[/tex]

[tex]pH=4.77+log1[/tex]

[tex]pH=4.77[/tex]

Answer:

1087.84 J

Explanation:

From the question given above, the following data were obtained:

Mass of metal (Mₘ) = 70 g

Temperature of metal (Tₘ) = 80 °C

Mass of water (Mᵥᵥ) = 100 g

Temperature of water (Tᵥᵥ) = 22 °C

Equilibrium temperature (Tₑ) = 24.6 °C

Heat lost by metal (Qₘ) =?

NOTE: Specific heat capacity of water (Cᵥᵥ) = 4.184 J/gºC

Heat lost by metal (Qₘ) = Heat gained by water (Qᵥᵥ)

Qₘ = Qᵥᵥ

Thus, we shall determine the heat gained by water. This can be obtained as follow:

Qᵥᵥ = MᵥᵥCᵥᵥ(Tₑ – Tᵥᵥ)

Qᵥᵥ = 100 × 4.184 (24.6 – 22)

Qᵥᵥ = 418.4 × 2.6

Qᵥᵥ = 1087.84 J

Thus, the heat gained by water is 1087.84 J.

Heat lost by metal (Qₘ) = Heat gained by water (Qᵥᵥ)

Qₘ = Qᵥᵥ

Qᵥᵥ = 1087.84 J

Qₘ = 1087.84 J

Therefore, the heat lost by the metal is 1087.84 J

A 70.0‑g piece of metal at 80.0 °C is placed in 100 g of water at 22.0 °C contained in a calorimeter. After reaching a temperature of 24.6 °C, the heat given up by the metal to the water is -1.08 kJ.

A calorimeter is an object used for calorimetry, or the process of measuring the heat of chemical reactions or physical changes as well as heat capacity.

A 70.0‑g piece of metal at 80.0 °C is placed in 100 g of water at 22.0 °C contained in a calorimeter. The final temperature of the system is 24.6 °C.

Let's use the following expression to calculate the heat absorbed by the water.

Qw = c × m × ΔT

Qw = (4.184 J/g.°C) × 100 g × (24.6 °C - 22.0 °C) = 1.08 kJ

where,

According to the law of conservation of energy, the sum of the heat absorbed by the water and the heat released by the metal (Qm) is zero.

Qw + Qm = 0

Qm = -Qw = -10.8 kJ

A 70.0‑g piece of metal at 80.0 °C is placed in 100 g of water at 22.0 °C contained in a calorimeter. After reaching a temperature of 24.6 °C, the heat given up by the metal to the water is -1.08 kJ.

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Answer:

Fe(NO3)3, Cr(NO3)3, Co(NO3)3

Explanation:

According to the question, no precipitate is observed when HCl was added. This means that we must rule out AgNO3.

Again, the sulphides of Cu^2+, Bi^3+ are soluble in acidic medium but according to the question, the sulphides do not precipitate at low pH hence Cu(NO3)2 and Bi(NO3)3 are both ruled out.

The sulphides of Fe^3+, Cr^3+ and Co^3+ all form precipitate in basic solution hence Fe(NO3)3, Cr(NO3)3, Co(NO3)3 may be present.

The presence of Ca(NO3)2 and KNO3 may be confirmed by flame tests.

Answer:

Aqueous workup.

Explanation:

The reaction of hexyl magnesium bromide with acetone yields a tertiary alcohol. There is an organic phase and an aqueous phase.

Aqueous workup is the process of recovering the pure tertiary alcohol from the organic phase of the system.

Hence, in order to complete the reaction of hexyl magnesium bromide with acetone, aqueous workup is required.

Answer:

[tex]M_{CO_2}= 25.7g[/tex]

Explanation:

From the question we are told that:

Temperature [tex]T=27.0[/tex]

Volume [tex]V=30L[/tex]

Pressure [tex]P=0.480atm[/tex]

Generally the equation for Ideal gas is mathematically given by

PV=nRT

Therefore

[tex]n=\frac{0.480 x 30}{0.08205 x 300}[/tex]

[tex]n=0.59moles[/tex]

Generally Mass of CO2 is given as

[tex]M_{CO_2}= 0.59 * 44 g/mol[/tex]

[tex]M_{CO_2}= 25.7g[/tex]

Answer:

4.27 g

Explanation:

Number of moles = concentration × volume

Concentration = 0.121 M

Volume = 250 mL

Number of moles = 0.121 M × 250/1000 L

Number of moles = 0.03 moles

Number of moles = mass/molar mass

Mass= Number of moles × molar mass

Mass= 0.03 moles × 142.394 g/mol

Mass = 4.27 g

Answer:

Two molecules of hydrogen combine with two molecules of oxygen to form hydrogen peroxide. Hence, its chemical formula is H2O2. It is the simplest peroxide (since it is a compound with an oxygen-oxygen single bond). Hydrogen peroxide has basic uses as an oxidizer, bleaching agent and antiseptic

Answer:

it is 11.55 and ik because I just had that question

18.0 grams of copper(II) phthalocyanine would be produced by the complete cyclotetramerization of 0.125 moles of phthalonitrile in the presence of excess copper(II) chloride.

Let's consider the following balanced equation.

4 C₈H₄N₂(l) + CuCl₂(s) → Cu(C₃₂H₁₆N₈)(s) + Cl₂(g)

The molar ratio of C₈H₄N₂ to Cu(C₃₂H₁₆N₈) is 4:1. The moles of Cu(C₃₂H₁₆N₈) produced from 0.125 moles of C₈H₄N₂ are:

[tex]0.125 mol C_8H_4N_2 \times \frac{1molCu(C_{32}H_{16}N_8)}{4mol C_8H_4N_2} = 0.0313 molCu(C_{32}H_{16}N_8)[/tex]

The molar mass of Cu(C₃₂H₁₆N₈) is 576.07 g/mol. The mass corresponding to 0.0313 moles of Cu(C₃₂H₁₆N₈) is:

[tex]0.0313 moles \times \frac{576.07g}{mol} = 18.0 g[/tex]

18.0 grams of copper(II) phthalocyanine would be produced by the complete cyclotetramerization of 0.125 moles of phthalonitrile in the presence of excess copper(II) chloride.

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Answer:

mass number

Explanation:

because the mass

From  the information given;

To determine the mass flow rate, let's start by understanding some concepts and parameters.

The power is known to be the energy per unit of time. Mathematically, it can be written as:

[tex]\mathbf{Power = \dfrac{Energy}{Time}}[/tex]

[tex]\mathbf{P =\dfrac{E_p}{time}}[/tex]

[tex]\mathbf{P =\dfrac{m\times g\times z}{time}}[/tex]

where;

Thus;

[tex]\mathbf{E_p}[/tex] = m × 9.81 m/s² × 50 m

[tex]\mathbf{E_p}[/tex] = m × 490.5 (m²/s²)

Recall that:

∴

[tex]\mathbf{E_p}[/tex] = 0.91 × 490.5m (m²/s²)

[tex]\mathbf{E_p}[/tex] = 446.355m (m²/s²)

Since the resulting power transmission is said to be 8%

Then;

the loss in the power transmission (P) = 100% - 8% ×  446.355m (m²/s²)

the loss in the power transmission (P) = 92%  ×  446.355m (m²/s²)

the loss in the power transmission (P) = 0.92  ×  446.355m (m²/s²)

the loss in the power transmission (P) =  410.65m (m²/s²)

Finally;

P = 410.65m (m²/s²)

[tex]\mathbf{P = 410.65 \times m (\dfrac{m^2}{s^2})}[/tex]

replacing the values, we have:

[tex]\mathbf{200 = 410.65 \times m (\dfrac{m^2}{s^2})}[/tex]

[tex]\mathbf{m = \dfrac{200 watt}{410.65\times (\dfrac{m^2}{s^2})}}[/tex]

[tex]\mathbf{m = \dfrac{200 \dfrac{J}{s}}{410.65\times (\dfrac{m^2}{s^2})}}[/tex]

since 1 J/s = 1 kgm²/s²)

Then:

[tex]\mathbf{m = \dfrac{200 \dfrac{\dfrac{kg\times m^2}{s^2}}{s}}{410.65\times (\dfrac{m^2}{s^2})}}[/tex]

[tex]\mathbf{m = \dfrac{200 \ {kg}}{410.65 \ s}}[/tex]

mass flow rate of the water (m) = 0.487 kg/s

Therefore, we can conclude that the mass flow rate of the water required to power a 200 W bulb light is 0.487 kg/s

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Explanation:

here's the answer to your question

Answer:

False

Explanation:

The statement ; Regardless of any concentration of ammonium solution the precipitate of unknown halide after 0.1M AgNO3 will remain is FALSE

This is Because the remaining concentration of AgNO3 is dependent on the solubility of Ag⁺

Answer:

[tex]T_2= 36.7 \textdegree C[/tex]

Explanation:

Mass of Water [tex]m_w=6.90kg[/tex]

Temperature [tex]T=34.7 degrees[/tex]

Heat Flow [tex]H=57.1kJ[/tex]

Specific heat capacity of water [tex]\mu= 4.18J.g^(-1).K^(-1)[/tex]

Generally the equation for Final Temperature is mathematically given by

[tex]M*\mu *T_1 + Q = M*\mu *T_2[/tex]

[tex]T_2=\frac{M*\mu *T_1 + Q }{M*\mu}[/tex]

Therefore

[tex]T_2=\frac{6.90*4.18*34.7 + 57.1}{6.90*4.18}[/tex]

[tex]T_2= 36.7 \textdegree C[/tex]

Kc require (aqueous/gaseous) products to be on the numerator and (aqueous/gaseous) reactants to be in the denominator, whereas Ksp will require (aqueous) products to be on the numerator and (aqueous) reactants to be in the denominator. Both require products on top and reactants in the bottom.

K = [products] / [reactants]

Kc is used when a reaction reaches dynamic equilibrium, whereas Ksp is used when an insoluble ionic solid dissolved by a tiny amount in a solution, as well as in determining whether or not a precipitate will form.

Kc can be used to measure equilibrium concentration for all reactions, whereas Ksp is limited to only ionic compounds' solubility.

The decomposition of HI (g) will required the use of Kc since the species are all gaseous, and gases cannot be ionic.

Answer:

lots more of the carbon 12 than the others

havent calculated it percentage-wise but you can see its very close to 12 meaning it is of far greater abundance that carbon 13 and 14

Explanation:

Answer:

The percent abundance of oxygen-18 is 1.9066%.

Explanation:

The average atomic mass of oxygen is given by:

[tex] m_{O} = m_{^{16}O}*\%_{16} + m_{^{17}O}*\%_{17} + m_{^{18}O}*\%_{18} [/tex]

Where:

m: is the atomic mass

%: is the percent abundance

Since the sum of the percent abundance of oxygen isotopes must be equal to 1, we have:  

[tex] 1 = \%_{16} + \%_{17} + \%_{18} [/tex]

[tex] 1 = x + 3.2 \cdot 10^{-4} + \%_{18} [/tex]

[tex] \%_{18} = 1 - x - 3.2 \cdot 10^{-4} [/tex]

Hence, the percent abundance of O-18 is:  

[tex] m_{O} = m_{^{16}O}*\%_{16} + m_{^{17}O}*\%_{17} + m_{^{18}O}*\%_{18} [/tex]  

[tex]15.9982 = 15.972*x + 16.988*3.2 \cdot 10^{-4} + 17.970*(1 - 3.2 \cdot 10^{-4} - x)[/tex]

[tex] x = 0.980614 \times 100 = 98.0614 \% [/tex]                                                              

Hence, the percent abundance of oxygen-18 is:

[tex]\%_{18} = (1 - 3.2 \cdot 10^{-4} - 0.980614) \times 100 = 1.9066 \%[/tex]                      

Therefore, the percent abundance of oxygen-18 is 1.9066%.

I hope it helps you!                                                      

since we are given the moles for Co and O, we'll divide both of those moles by the lowest mole quantity, which is, in this case, 2.59. After dividing, we see that the ratio of O to Co is 2:1. So, for every 1 Co atom, there has to be 2 O atoms. we can then insert the 2 in for OH to satisfy this ratio.

Activation energy is the energy needed to begin breaking the bonds of reactants. Hence, option A is correct.

Activation energy is defined as the minimum amount of energy necessary to initiate a chemical reaction.

Hence, activation energy is the energy needed to begin breaking the bonds of reactants.

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#SPJ5

Answer:

Line graphs are used to track changes over short and long periods of time. When smaller changes exist, line graphs are better to use than bar graphs. Line graphs can also be used to compare changes over the same period of time for more than one group.

Answer:

endet nach selam nw

4gh7

Answer:

c

Explanation:

table of data help us to understand and present our work better

I did it and got it right, it's c

Answer:

information is missing

Explanation

reaction is needed to solve the problem

Answer:

Unfortunately, we don`t know how to convert plastic material into electricity yet. I suppose an idea is for someone to invent a machine similar to biomass, where dead plants created energy, but here it`s plastic. The only issue is that it could release deadly chemicals.

Sorry if this isn`t much help, but there isn`t really an answer.   :/

Answer: The property of magnesium that is exhibited by it is DUCTILITY. The correct option is A.

Explanation:

Magnesium is a member of the alkaline earth metals. It occurs in nature, only in the combined state, as Epsom salt, dolomite and in many trioxosilicates( IV) including talc and asbestos. They have the following physical properties:

--> Appearance: they are silvery-white solids

--> Relative density: It has a relative density of 1.74

--> DUCTILITY: it's very ductile in nature

--> melting point: it has a melting point of 660°C.

--> Conductivity: They are good conductor of heat and electricity.

Furthermore, DUCTILITY is the physical property of a metal associated with the ability to be hammered thin or stretched into wire without breaking. A metal such as magnesium can therefore be coiled as a thin ribbon without fracturing due to its ductile physical properties.

Answer:

D

Explanation:

Desalination

Removing salt from sea water is known as desalination

Answer:

Mn2+(aq) + 2H2O(l)  ⇒ MnO2(s) + 4H+(aq) + 2e-

Explanation:

Step 1: Data given

The oxidation number of manganese ion (Mn2+ ) is +2

The oxidation number of manganese dioxide  is +(MnO2)4

This means the oxidation number from Mn will go from +2 to +4, since it's increased, this is an oxidation reaction

Mn2+(aq)  ⇒ MnO2(s)

We have to balance both sides. Mn is already the same. But on the right side we have O atoms. T obalance both sides we have to add O atoms to the left side. This by adding 2x H2O

Mn2+(aq) + 2H2O(l)  ⇒ MnO2(s)

Now the amount of O atoms is balanced, but we have H- atoms at the left side. To balance we have to add 4 H atoms to the right side

Mn2+(aq) + 2H2O(l)  ⇒ MnO2(s) + 4H+(aq)

Now the amount of atoms is balanced at both sides. We also have to check if the charge on both sides is the same.

Since the left side has a charge of +2, and right has a charge of +4, we have to add 2 electrons to balance this.

Mn2+(aq) + 2H2O(l)  ⇒ MnO2(s) + 4H+(aq) + 2e-

Answer:

6.684g

Explanation:

Here, we can use the mole ratio of the gases to calculate.

We know that the mole ratio of the gases equate to their number of moles.

Firstly, we calculate the number of moles of the oxygen gas. The number of moles of the oxygen gas is equal to the mass of the oxygen gas divided by the molar mass of the oxygen gas. The molar mass of the oxygen gas is 32g/mol

Thus, the number of moles produced is 5.98/32 = 0.186875

Where do we move from here?

We know that if we place the partial pressure of oxygen over the total pressure, this would be equal to the number of moles of oxygen divided by the total number of moles. Now let’s do this.

449/851 = 0.186875/n

n =(0.186875 * 851)/449

n = 0.3542

Now we do the same for argon to get the number of moles of argon.

Firstly, we use dalton’s partial pressure law to get the partial pressure of argon. In the simplest form, the partial pressure of argon is the total pressure minus the partial pressure of oxygen.

P = 851 - 449 = 402 mmHg

We now use the mole ratio relation.

402/851 = n/0.3542

n = (402 * 0.3542) / 851

n = 0.1673

Since we now know the number of moles of argon, we can use this multiplied by the atomic mass of argon to get the mass.

The atomic mass of argon is 39.948 amu

The mass is thus 39.948 * 0.1673 = 6.684g

Thermochemistry has to do with  heat evolved or absorbed in a chemical reactions. Thermochemical equations are equations in which the heat of reaction is included in the reaction equation. The reaction of moles and heat of reaction is important here.

This question has to do with thermochemistry and thermochemical equations.

The answers to each of the questions are shown below;

a) 300.52 KJ

b) 11.39 g

c) 5.78 g

The equation of the thermochemical reaction is;

2C12H26 + 37O2-------> 24CO2 + 15026KJ

Number of moles of CO2 released = 21.3g/44g/mol = 0.48 moles

From the reaction equation;

15026KJ is released when 24 moles of CO2 is released

x KJ is released when  0.48 moles of CO2 is released

x = 15026KJ  * 0.48 moles/24 moles

x = 300.52 KJ

b) If 2 moles of C12H26 released 15026KJ of heat

     x moles of C12H26  released 500.00KJ

x = 2 * 500.00KJ/15026KJ

x = 0.067 moles

Mass of C12H26 consumed =  0.067 moles * 170 g/mol = 11.39 g

c) Heat gained by water = heat released by combustion of kerosene

Heat gained by water = 0.75 Kg * 4200  * (90 -10)

Heat gained by water = 252 KJ

If 2 moles of C12H26  produced 15026KJ

x moles of C12H26  produces 252 KJ

x = 2 * 252/15026

x = 0.034 moles

Mass of C12H26   = 0.034 moles *  170 g/mol = 5.78 g

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Answer: The mass of copper (II) nitrate produced is 105.04 g.

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of copper = 35.5 g

Molar mass of copper = 63.5 g/mol

Plugging values in equation 1:

[tex]\text{Moles of copper}=\frac{35.5g}{63.5g/mol}=0.560 mol[/tex]

The given chemical equation follows:

[tex]3Cu(s)+8HNO_3(aq)\rightarrow 3Cu(NO_3)_2(aq)+2NO(g)+4H_2O(l)[/tex]

By the stoichiometry of the reaction:

If 3 moles of copper produces 3 moles of copper (II) nitrate

So, 0.560 moles of copper will produce = [tex]\frac{3}{3}\times 0.560=0.560mol[/tex] of copper (II) nitrate

Molar mass of copper (II) nitrate = 187.56 g/mol

Plugging values in equation 1:

[tex]\text{Mass of copper (II) nitrate}=(0.560mol\times 187.56g/mol)=105.04g[/tex]

Hence, the mass of copper (II) nitrate produced is 105.04 g.

Explanation:

the molecular weight of K2SO3 is 158. 2598 m/s.