Answer:
So, when bromine comes near the ethylene pi bond, it attacks the electron and grabs it, but the second bromine steals it away and departs as Br-. After all, bromine is more electronegative than carbon; the first bromine is just a link in the chain of events that allows the second bromine to escape with an electron.
The density of toluene (C7H8) is 0.867 g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolving 8.10 g of thiophene in 250.0 mL of toluene.
(a) Calculate the mole fraction of thiophene in the solution.
(b) Calculate the molality of thiophene in the solution.
(c) Assuming that the volumes of the solute and solvent are additive, what is the molarity of thiophene in the solution?
Considering the solution of mole fraction, molality and molarity, you obtain that:
(a) the mole fraction of thiophene in the solution is 0.039.
(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].
(c) the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].
You know that:
Density toluene (C₇H₈)= 0.867 [tex]\frac{g}{mL}[/tex]Density thiophene (C₄H₄S)= 1.065 [tex]\frac{g}{mL}[/tex] Volume of toluene (C₇H₈)= 250 mL= 0.250 L (being 1000 mL= 1 L)Mass of thiophene (C₄H₄S)= 8.10 grams(a) Mole fractionThe molar fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution.
Being the molar mass of each compound equals to:
Toluene (C₇H₈)= 92 [tex]\frac{g}{mol}[/tex]Thiophene (C₄H₄S)= 84 [tex]\frac{g}{mol}[/tex]the number of moles of each compound can be calculated as:
Toluene (C₇H₈)= [tex]250 mLx\frac{0.867 grams}{1 mL} x \frac{1 mole}{92 grams}[/tex]= 2.35 molesThiophene (C₄H₄S)= [tex]8.10 gramsx\frac{1 mole}{84 grams}[/tex]= 0.096 molesThe total moles is obtained from the addition of the moles of the solute (C₄H₄S) and the solvent (C₇H₈):
total moles = moles C₄H₄S + moles C₇H₈ = 0.096 moles + 2.35 moles = 2.45 moles
Then, the mole fraction of thiophene in the solution can be calculated as:
[tex]mole fraction of thiophene=\frac{0.096 moles}{2.45 moles}[/tex]
Solving:
mole fraction of thiophene= 0.039
Finally, the mole fraction of thiophene in the solution is 0.039.
(b) MolalityMolality is 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]
In this case, you know:
number of moles of solute (C₄H₄S)= 0.096 moles Mass of solvent = [tex]250 mLx\frac{0.867 grams}{1 mL}[/tex] = 216.75 g = 0.21675 kg (being 1000 g=1 kg)Replacing:
[tex]Molality C_{4} H_{4}S =\frac{0.096 moles}{0.21675 kg}[/tex]
molality C₄H₄S= 0.4429 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].
(c) MolarityMolarity is the number of moles of solute that are dissolved in a certain volume and is determined by the following expression:
[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]
Assuming that the volumes of solute and solvent are additive, you can add the volume of C₄H₄S and C₇H₈.
But first, you need yo know the volume of C₄H₄S, which can be calculated from the mass and density:
[tex]Volume C_{4} H_{4}S =8.10 grams\frac{1 mL}{1.065 grams}[/tex]= 7.606 mL= 0.007606 L
Then, the total volume of the solution is calculated as:
total volume of the solution= volume C₇H₈ + volume C₄H₄S
total volume of the solution= 0.250 L + 0.007606 L = 0.257606 L
So, the molarity of thiophene in the solution can be calculated as:
[tex]Molarity C_{4} H_{4} S=\frac{number of moles of C_{4} H_{4} S}{totalvolumeof the solution}[/tex]
Replacing:
[tex]Molarity C_{4} H_{4} S=\frac{0.096 moles}{0.257606 L}[/tex]
Solving:
Molarity C₄H₄S= 0.373 [tex]\frac{moles}{L}[/tex]
Finally, the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].
In summary, you get:
(a) the mole fraction of thiophene in the solution is 0.039.
(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].
(c) the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].
Learn more about
density: brainly.com/question/952755?referrer=searchResults brainly.com/question/1462554?referrer=searchResults mole fraction: brainly.com/question/14434096?referrer=searchResults brainly.com/question/10095502?referrer=searchResults molality brainly.com/question/20366625?referrer=searchResults brainly.com/question/4580605?referrer=searchResults molarity with this example: brainly.com/question/15406534?referrer=searchResultsWhich of the following is NOT true about one mole?
the number of atoms in 1 mole of carbon equals the number of atoms in 1 mole of boron
O 12 g of carbon equals one mole of carbon atoms
the mass of 1 mole of carbon atoms equals the mass of 1 mole of boron atoms
one mole contains 6.02 x 10
23
particles
The number of atoms in 1 mole of carbon equals the number of atoms in 1 mole of boron is false because the molar mass of carbon is different from that of boron. Option A is correct.
The number of moles of an element is expressed as the ratio of the mass of the substance to its molar mass.Moles = Mass/Molar massThis shows that the number of moles of the substance is dependent on the molar mass of the substance.
From the listed option the number of atoms in 1 mole of carbon equals the number of atoms in 1 mole of boron is false because the molar mass of carbon is different from that of boron
Learn more on moles here: https://brainly.com/question/24256751
A control. during a experiment
A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements.
what molecules must the plant take in so the process of photosynthesis can occur
Answer:
Glucose molecules
Explanation:
How many parents does asexual reproduction involve?
Answer:
only 1 parent is needed! and the offspring is a identical copy of the parent
How many electrons can be described by the following quantum numbers: n=2, 1=-1, m-1.
Answer:
6 electrons
Explanation:
The principal quantum number n; describes the energy level and here, it is 2.
The azimuthal or secondary quantum number l is given as 1, we are describing the p-orbital
The magnetic quantum number is -1, and we have 3 sub-orbitals here:
It is a 2p-suborbital
So; in each sub orbital we have 2 electrons
The number of electrons that can be described here = 2 x 3 = 6 electrons.
True or false: potential energy increases as like charges get closer to one another
do all atoms only have one oxidation state
Elements on the periodic table are arranged?
Answer:
In atomic number
And size
And nature of each (metal, non, or metalloide)
[tex]\Large \boxed{\sf by \ their \ properties}[/tex]
Every element has a set of particular characteristics. Each has a unique atomic and mass number because they contain a different ratio of protons and neutrons. The number of protons in an element mirrors the element's atomic number. The mass number equals the sum of the element's protons and neutrons.
According to increasing atomic numbers, chemical elements get organized. Periods and groups are the names of the horizontal rows and vertical columns, respectively. The chemical characteristics of elements within the same group are comparable due to their similar valency and number of outer electrons.
Compound A reacts with Compound B to form only one product, Compound C, and it's known the usual percent yield of C in this reaction is 72.%. Suppose 3.5g of A are reacted with excess Compound B, and 6.5g of Compound C are successfully isolated at the end of the reaction.
A. What was the theoretical vield of C?
B. How much B was consumed by the reaction?
Answer:
A. Theoretical yield of C is 9.03 g
B. Mass of B consumed is 5.53 g
Explanation:
A. Determination of the theoretical yield of C.
Actual yield of C = 6.5 g
Percentage yield of C = 72.%
Theoretical yield of C =?
Percentage yield = Actual yield /Theoretical yield × 100
72% = 6.5 / Theoretical yield
72 / 100 = 6.5 / Theoretical yield
Cross multiply
72 × Theoretical yield = 100 × 6.5
72 × Theoretical yield = 650
Divide both side by 72
Theoretical yield = 650 / 72
Theoretical yield = 9.03 g
Therefore, the theoretical yield of C is 9.03 g
B. Determination of the mass of B consumed.
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
A + B —> C
Mass of A = 3.5 g
Mass of C = 9.03 g
Mass of B =?
A + B = C
3.5 + B = 9.03
Collect like terms
B = 9.03 – 3.5
B = 5.53 g
Thus, the mass of B consumed in the reaction is 5.53 g
Which statement describes a change that occurs during a chemical reaction?
OA. The atoms in a substance start to move faster until they are no longer touching each other.
OB.
Atoms in the original substances are arranged in a different way to make new substances
OC!
The atoms in a substance change their properties so they can become a new substance.
OD.
Atoms in the original substances are changed into different atoms to make new substances,
Answer - B Atoms in the original substances are arranged in a different way to make new substances
In order to heat a round bottom flask in a heating mantle, plug the heating mantle into _______.Turn the heat up _________, and do not exceed _______ of the maximum output of the device.
Answer:
A Variac or Powermite; gradually; 50-60%.
Explanation:
A chemical reaction can be defined as a chemical process which typically involves the transformation or rearrangement of the atomic, ionic or molecular structure of an element through the breakdown and formation of chemical bonds to produce a new compound or substance.
Some of the laboratory apparatus (equipment) used for conducting a chemical reaction are conical flask, Bunsen burner, beaker, tongs, crucible, round bottom flask etc.
In order to heat a round bottom flask in a heating mantle, plug the heating mantle into a Variac or Powermite which is typically used for controlling the level of temperature. Turn the heat up gradually, and do not exceed 50-60% of the maximum output of the device, so as to avoid any electrical issues such as overloading, short-circuit etc.
The safety precautions that must be taken when using a round bottom flask are;
I. A proper inspection of the round bottom flask for cracks, irregularities or any imperfection.
II. Ensure you avoid heating the flask while it is closed.
III. When suspending the round bottom flask on a stand, you should ensure that you use a clamp for stability.

Someone unscramble the first mystery element because I don’t know how to.
-unnecessary comments will be reported
Answer:
Calcium
Explanation:
The symbol for the element with a mass number of 27 is actually Al for Aluminum instead of Co for Cobalt. Mass number refers to atomic mass, not atomic number.
Aluminum has an atomic mass of 26.982 or 27.
The letters to unscramble are I, M, C, Al, U, and C.
The mystery element is Calcium.
Hope that helps.
who wants to be my bay ;D
Answer:
0.0
Explanation:
Answer:
no stranger danger!
Explanation:
nice profile pic tho
May someone help me unscramble these.
-unnecessary comments will be reported.
Answer:
Potassium
Explanation:
The symbol for the element with a mass number of 169 is Tm for Thulium.
The letters to unscramble are S, Si, Tm, P, Au, and o.
The mystery element is Potassium.
Hope that helps.
Name a famous transform fault in western North America
Answer:
Read this section of the text:
These raptors eat primarily flying insects, so they do most of their hunting on the wing.
What does primarily mean in this sentence?
Explanation:
I'm bored
The following graph shows a decay chain. Which part of the decay chain will take the most time?
the movement of cold, nutrient-rich water from the deep ocean to the ocean surface is known as?
Answer:
Upwelling! Its the process where the deep cold water rises to the surface! :)
Explanation:
Hope this helps! :)
Answer:
upwelling
Explanation:
If the theoretical yield of a reaction was calculated to be 39.2 grams and when the experiment was conducted the amount produced was 12.7 grams, the what is the percent yield of the experiment?
Answer:
32.4%
Explanation:
%Yield = Actual Yield/Theoretical Yield x 100% = (12.7/39.2)100% = 32.4%
What type of reaction is displayed below?
B12 + 2KI → 2KBr + 12
synthesis
В
decomposition
с
single replacement
double replacement
Answer:
double replacement
Explanation:
The reaction shown is a double replacement reaction.
It is also known as double decomposition or metathesis reaction.
In such a reaction, there is an actual exchange of partners to form new compounds.
One of the following is the driving force for such reaction:
formation of an insoluble compound or precipitateformation of water or any other non-ionizing compoundliberation of a gaseous product.What is the definition of an atmosphere? a portion of the electromagnetic spectrum that makes the sky look blue the blanket of gases that surrounds Earth and some other planets an area above Earth that scatters sunlight into all colors of the rainbow
Answer:
the blanket of gases that surrounds Earth and some other planets
Explanation:
The best definition of the atmosphere is that it is a portion of the earth that is a made up of a blanket of gases.
The atmosphere is not peculiar to the earth alone, some other planets also have atmospheric cover. The earth's atmosphere is divided into many different layers. The weather we see and experience on the earth surface is conditioned within the troposphere. This troposphere is the closest layer to the surface.any two substances whih are tasteless
Answer:
Taste comes from the stimulation of chemical receptors in nerve cells on the tongue by particular chemical structures of substances. If there are no chemical structures pertaining to any of the chemical sensors, the substance would appear to be tasteless. All of these chemicals interact with the sensors with the help of the medium of saliva which has a lot of water. For example: the salt sensors might be susceptible to ions and the sweet sensors might be susceptible to hydroxyl groups on the sugars.
Now, taste is not a very precise field of study. A same substance may taste subtly different to different people. Can we be sure that water has no taste? The chemical sensors are always exposed to water. It might be that there are no sensors for water. It might also be that the signal for water is negated as a background signal. If water did have a particular taste, one thing is for certain, we would be tasting water in every bite of food and even at times when we are not eating as we always have saliva in your mouth.
Hope this helps, have a wonderful day/night, and stay safe!
how will you ensure your server is protected from data hacks?
Answer:
Establish and Use a Secure Connection
Use SSH Keys Authentication
Secure File Transfer Protocol
Secure Sockets Layer Certificates
Use Private Networks and VPNs
Explanation:
How many moles are in 2.5 g of N2?
0.089 moles
KD 0.18 moles
1.3 moles
11 moles
Answer:
0.089
Explanation:
2.5/ 14= .178 then 0.178/ 2 again and you get 0.089
The moles of nitrogen in 2.5 grams of the compound is 0.089 moles. Thus option A is correct.
Moles can be calculated as the ratio of mass to molecular mass.
Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]
The mass of Nitrogen = 14 g/mol
The mass of diatomic nitrogen = 2 [tex]\times[/tex] mass of nitrogen
The mass of diatomic nitrogen = 2 [tex]\times[/tex] 14 g/mol
The mass of diatomic nitogen = 28 g/mol
The molecular weight of Nitrogen = 28g/mol
Given, the mass of Nitrogen = 2.5 g
Moles of nitrogen = [tex]\rm \dfrac{2.5}{28}[/tex]
Moles of Nitrogen = 0.089 moles.
The moles of nitrogen in 2.5 grams of the compound is 0.089 moles. Thus option A is correct.
For more information about a mole, refer to the link:
https://brainly.com/question/21898305
How do atoms form double or triple covalent bonds?
Answer:
Covalent bonding occurs when electrons are shared between atoms. Double and triple covalent bonds occur when four or six electrons are shared between two atoms, and they are indicated in Lewis structures by drawing two or three lines connecting one atom to another.
Explanation:
HELPPPPPPPPPP/AYUDAAAAAA
Answer:
*helps*
Explanation:
The transfer of heat by electromagnetic waves *
O Conduction
O Convection
O Radiation
Answer:
radiation
Explanation:
hope this helps!
a student requires to prepare 500ml of 0.1M potassium dichromate (vii) from 0.250M solution must be diluted to 500ml
The volume required : 0.2 L
Further explanationGiven
500ml of 0.1M potassium dichromate (vii)
0.25 solution
Required
The volume
Solution
We can use dilution formula :
M₁V₁=M₂V₂
M₁ = 0.25
M₂ = 0.1
V₂ = 500 ml = 0.5 L
The initial volume taken :
V₁=(M₂V₂)/M₁
V₁=(0.1 x 0.5)/0.25
V₁=0.2 L
PLZ HELP ME!!!! BEING TIMED!!!!
Answer:
it will A. d. e. f option above
How many grams of iron(III) hydroxide (106.87 g/mol) will precipitate if 50.0 mL of 0.500 M sodium hydroxide is added to 75.0 mL of 0.200 M iron(III) nitrate
Answer:
[tex]m_{Fe(OH)_3} = 0.891gFe(OH)_3[/tex]
Explanation:
Hello!
In this case, given the chemical reaction:
[tex]3NaOH(aq)+Fe(NO_3)_3(aq)\rightarrow 3NaNO_3(aq)+Fe(OH)_3(s)[/tex]
In such a way, given the volumes and molarities of each reactant, we can compute the moles of produced iron (III) hydroxide by each of them, via the 3:1 and 1:1 mole ratios:
[tex]n_{Fe(OH)_3}^{by\ NaOH}=0.0500L*0.500\frac{molNaOH}{L}*\frac{1molFe(OH)_3}{3molNaOH} =0.00833molFe(OH)_3\\\\n_{Fe(OH)_3}^{by\ Fe(NO_3)_3}=0.0750L*0.200\frac{molFe(NO_3)_3}{L}*\frac{1molFe(OH)_3}{1molFe(NO_3)_3} =0.0150molFe(OH)_3[/tex]
It means that the sodium hydroxide is the limiting reactant and 0.00833 moles of iron (III) hydroxide are produced; thus, the required mass is:
[tex]m_{Fe(OH)_3}=0.00833molFe(OH)_3*\frac{106.87gFe(OH)_3}{1molFe(OH)_3} \\\\m_{Fe(OH)_3} = 0.891gFe(OH)_3[/tex]
Best regards!