Answer:
THE NUMBER OF MOLES OF HELIUM NEEDED TO FILL A BALLOON AT A VOLUME OF 4.9 L AT 296 K AND 0.78 atm IS 0.00338 moles.
Explanation:
The number of moles is calculated using
PV = nRT
P = Pressure = 0.78 atm
V = volume = 4.9 L
R = gas constant = 0.082 Latm/molK
T = temperature = 296 K
n= number of moles
Substituting theses values and sloving for n, we obtain;
n = PV / RT
n = 0.78 * 4.9 / 0.082 * 296
n = 3.822 / 24.272
n = 0.00338 moles.
So therefore, the number of moles is 0.00338 moles.
Answer:
The number of moles of helium needed is 0.157 moles helium
Explanation:
Step 1: Data given
Volume of the balloon = 4.9 L
Temperature= 296 K
Pressure = 0.78 atm
Step 2: Calculate moles of helium gas
p*V = n*R*T
⇒with p = the pressure = 0.78 atm
⇒with V = the volume = 4.9 L
⇒with n = the number of moles of the helium gas = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol* K
with T = the temperature = 296 K
n = (p*V) / (R*T)
n = (0.78 atm* 4.9 L) / (0.08206 L*atm/mol*K * 296 K)
n = 0.157 moles of helium
The number of moles of helium needed is 0.157 moles helium
During El Niño years, why is Christchurch, New Zealand’s temperature cooler than usual?
Choose the claim that is most similar to your idea. Your response does not need to be the same as your partner's.
This is why Christchurch, New Zealand’s air temperature is cooler than usual during El Niño years:
Claim 1: The amount of incoming energy from the sun changes.
Claim 2: Something about Earth’s surface (land or water) changes.
Claim 3: Something about the air changes.
Please get back to me quick, due in an hour. First to answer will be named brainliest! HELPP
Answer:
It's probably claim 3
Explanation:
It's not claim 1 because the amount of energy from the sun can't change and claim 2 doesn't really make sense.
When a gas particle changes phase into a liquid particle:
A. the particle loses energy
B. the particle gains energy
C. the particle has no change in energy
D. the change in energy depends on the type of gas
Answer:B
Explanation:
The movement in particles is faster than the particle movement in a solid and the attractive forces are much weaker.A gas is something with no definite volume and no definite shape. Gas particles are far apart and move rapidly and freely. The attractive forces between gas particles are very weak or absent.When a liquid is heated, the particles are given more energy. They start to move faster and further apart. At a certain temperature, the particles break free of one another and the liquid turns to gas. This is the boiling point.Particles in gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. Solid are tightly packed, usually in a regular pattern.Question 1 of 10
2 Points
An engineering team is conducting a wind tunnel test to examine the
aerodynamics of a car it has designed. Which part of the engineering process
is the team in?
O A. Do the work.
O B. Evaluate the results.
O C. Improve and redesign.
D. Identify a need.
SUBMIT
Explanation:
Evaluate the results, letter B
methane Express your answer as a condensed structural formula omitting all bonds (e.g CH3CH2CH3). nothing Request Answer Part B ethane Express your answer as a condensed structural formula omitting all bonds (e.g CH3CH2CH3). nothing Request Answer Part C pentane Express your answer as a condensed structural formula omitting all bonds (e.g CH3CH2CH3). nothing Request Answer Part D cyclopropane Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. Include all hydrogen atoms.
Answer:
a
The condensed structural formula for methane is
[tex]CH_4[/tex]
b
The condensed structural formula for ethane is
[tex]CH_3 CH_3[/tex]
c
The condensed structural formula for pentane is
[tex]CH_2(CH_2)_3CH_3[/tex]
d
The diagram for the structural formula for cyclopropane is shown on the first uploaded image
Explanation:
A student conducts an experiment to see how music affects plant growth. The student obtains four identical plants. Each one is potted in the same type of soil and receives the
same amount of sunlight and water each day. Plant A listens to classical music for three hours each day. Plant B listens to rock music for three hours each day. Plant C listens to
country music for three hours each day. Plant D does not listen to any music at all.
2. Based on the experiment in the scenario, which visual aid would be most helpful in showing the change in the plants' heights over time?
O A. A timeline
OB. A line graph
OC. A pie chart
D. A bar graph
Answer:
The type of music each plant listens to.
Explanation:
A variable is any factor or condition whose value is changing in an experiment. A variable can occur in different types or quantity, and three types of variable (independent, dependent, and controlled) can be found in an experiment. In the experiment described above, "the type of music each plant listens to" is the variable. It is an independent variable whose value is changing because it exists in different types and it is the one that the student is observing its effect on the plant’s growth. In this experiment, this variable which differ will also produce different results (or effects).
If you have 67.31g of CH4, how many moles do you have?
Answer:
If you have 67.31 g of CH₄, you have 4.21 moles
Explanation:
To know the amount of moles if you have 67.31 g of CH₄, you must know the molar mass, that is, the mass of one mole of a substance, which can be an element or a compound.
On the periodic table, the molar mass of the elements, also called the atomic mass or atomic weight, can be found at the bottom of the element. In this case:
C: 12 g/moleH: 1 g/moleTo calculate the molar mass of a compound, the molar mass of the elements of the compound must be added multiplied by the times they appear. So in this case the molar mass of CH₄ is:
CH₄= 12 g/mole + 4* 1 g/mole= 16 g/mole
Now you can apply the following rule of three: if 16 g are contained in 1 mole of CH4, 67.31 g in how many moles are present?
[tex]moles=\frac{67.31 g*1 mole}{16 g}[/tex]
moles= 4.21
If you have 67.31 g of CH₄, you have 4.21 moles
Which chemical is responsible for opening the hair cuticle?
A
Peroxide
B
Ammonia
С
Powder persulphate
D
None of the above
1. A substance that gets dissolved to create a solution is best described as to
as
Answer:
Solute
Explanation
A substance that gets dissolved to create a solution is best described as to as
You have 0.00891 g of platinum. What is this in micrograms?
You weighed out 0.020 g of your crude aspirin product in order to determine the amount of salicylic acid impurity. Following the procedure outlined in the manual, you dissolved the solid and diluted the solution to a final volume of 10.0 mL. If the absorbance of your sample solution was 1.07, what was the percent salicylic acid in your product
Answer:
The correct answer is 7.8 percent.
Explanation:
As mentioned in the given question, the absorbance (A) of the sample solution is 1.07. To find the concentration of aspirin, Beer's law is used, that is, A = ebc
Here, e is the extinction coefficient, which is equal to 139.322 M^-1cm^-1 as per the standard value for salicylic acid, b is the pathlength, which is equivalent to 1 cm. Now putting the values we get,
A = ebc
c = A / (eb)
c = 1.07 / (139.322 × 1)
c = 0.00768 M
Now to determine the percent salicylic acid in the sample, there is a need to compare the value of concentration determined with the concentration of aspirin given initially.
0.02 grams is the initial concentration of aspirin mentioned in the question. The molar mass of aspirin is 240 g/mol.
Therefore, the moles of aspirin will be,
0.02 / 240 = 8.33 × 10^-5 moles
The final volume of the diluted solution given is 10 ml or 0.01 liters.
The molarity of aspirin in the diluted solution will be,
c1 = 8.33 × 10^-5 / 0.01 = 8.33 × 10^-3 M or 0.00833 M
Now, the percent of salicylic acid in the product will be,
c1 - c / c1 × 100
(0.00833 - 0.00768) / 0.00833 × 100 = 7.8 %
Absorbance is directly proportional to the concentration of the solution. The absorbance can be calculated if the molar absorptivity, path length, and concentration of the absorbing species are known.
The percent of salicylic acid in the solution is 7.8%
Given that:
Absorbance of the solution is = 1.07
Path length = 1 cm.
Applying Beer's Law,
A = ε b c
where,
c = concentration, A = absorbance, ε = constant, and b = path length
Now, putting the values in above equation
c = [tex]\dfrac{\text{A}}{\text {(e b)}}[/tex]
c = [tex]\dfrac{1.07}{139.32 \times 1}[/tex] ( ε = 139.32)
c = 0.00768 M
Now, to calculate the percent of the salicylic acid in the solution, we will compare the given concentration of the aspirin.
As we know:
Given mass of aspirin = 0.02 g
Molar mass of aspririn = 240
Number of moles of aspirin = 0.02 / 240 = 8.33 x 10⁻⁵
Now, the molarity of aspirin is:
[tex]\text{Molarity}&= \dfrac{8.33 \times 10^{-5}}{0.01}\\\\\text{Molarity}&= 8.33 \times 10^{-5}[/tex]
Now, the percent of the salicylic acid is:
[tex]\dfrac{\text {C}_1 - \text C}{\text {C}_1 \times 100}[/tex]
[tex]\dfrac{(0.00833 - 0.00768)}{0.00833 \times 100}[/tex]
Percent of Salicyclic acid = 7.8%.
Thus, the percentage of the salicylic acid in the given solution is 7.8%.
To know more about Absorbance, refer to the following link:
https://brainly.com/question/17062521
Scoring: Your score will be based on the number of correct matches minus the number of incorrect matches. There is no penalty for missing matches. Use the References to access important values if needed for this question. Indicate whether each of the following compounds will gave an acidic, basic or neutral solution when dissolved in water.
1. ammonium bromide
2. potassium cyanide
3. sodium chloride
4. potassium iodide
Answer:
Explanation:
1 ) Ammonium bromide is a salt of ammonium hydroxide and hydrogen bromide . The former is a weak base and the later is a strong acid so the salt will make acidic solution in water. It happens due to salt hydrolysis.
2 ) Potassium cyanide is salt of potassium hydroxide and hydrogen cyanide . The former is strong base and the later is weak acid so its salt will be basic in nature .
3 ) sodium chloride is a salt of sodium hydroxide and hydrogen chloride . The former is strong base and later is strong acid. So the salt is neutral .
4 ) Potassium iodide is a salt of potassium hydroxide and hydrogen iodide . The former is a strong base and the later is a strong acid . So the salt is neutral or a bit basic.
Calculate the pH of a [0.000765) M solution of KOH
Answer:
pH=10.88
Explanation:
Hello,
In this case, since potassium hydroxide is completely dissociated as shown below:
[tex]KOH\rightarrow K^++OH^-[/tex]
For which we understand it is a base, more specifically, a strong base; it means that the concentration of the OH⁻ equals the concentration of the potassium hydroxide, that is 0.000765M, for that reason we can directly compute the pOH:
[tex]pOH=-log([OH^-])=-log(0.000765)=3.12[/tex]
Finally, since the pOH and the pH are related by:
[tex]pOH+pH=14[/tex]
The pH turns out:
[tex]pH=14-3.12\\pH=10.88[/tex]
Best regards.
The image shows two different species. the image is a dog and a lizered
Which is a shared characteristic of these two species?
tail
scales
hair
body shape
Answer:
the tail
Explanation:
Answer:
A.) tails
Explanation:
Anatom that has lewer neutrons than protons and more electrons than protons is
Answer:
a negative ion, and an isotope.
Explanation:
The perfect atom consists of an equal balance in all 3. If the neutrons are not even with the protons, it is an isotope since it is like another version of the so called (but not actually) 'perfect' atom. If there is more electrons, the charge is negative, making it an ion.
10. When the pressure on a gas inetcases three times, by how much will the volume incrcase or decrease?
Answer:The answer to this question comes from experiments done by the scientist Robert Boyle in an effort to improve air pumps. In the 1600's, Boyle measured the volumes of gases at different pressures. Boyle found that when the pressure of gas at a constant temperature is increased, the volume of the gas decreases. when the pressure of gas is decreased, the volume increases. this relationship between pressure and volume is called Boyle's law.
Explanation: So, at constant temperature, the answer to your answer is: the volume decreases in the same ratio as the ratio of pressure increases.
BUT, in general, there is not a single answer to your question. It depend by the context.
For example, if you put the gas in a rigid steel tank (volume is constant), you can heat the gas, so provoking a pressure increase. But you won't get any change in volume.
Or, if you heat the gas in a partially elastic vessel (as a tire or a soccer ball) you will get both an increase of volume AND an increase of pressure.
FINALLY if you inflate a bubblegum ball, the volume will be increased without any change in pressure and temperature, because you have increased the NUMBER of molecules in the balloon.
There are many other ways to change volume and pressure of a gas that are different from the Boyle experiment.
Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine because A.the bromine radical is more reactive and therefore more selective. B.the chlorine radical is more reactive and therefore more selective. C.the chlorine radical is less reactive and therefore more selective. D.the bromine radical is less reactive and therefore more selective. E.none of these choices.
Answer:Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine because the bromine radical is less reactive and therefore more selective.
Explanation: Halogenation occurs when a halogen replaces one or more hydrogen atoms in an organic compound ie chlorine or bromine with the reactivity of the halogens decreasing in the order of F2 > Cl2 > Br2 > I2
Since fluorine reacts explosively making it is difficult to control, and iodine is unreactive. Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine with Chlorination ie chlorine radical being more reactive and not selective and the Bromination of alkanes ie bromine radical occurring similarly but slower and less reactive but more selective which is due to the fact that a bromine atom is less reactive in the hydrogen abstraction than a chlorine atom evidence in the higher bond energy of H-Cl than H-Br.
dentify the missing information for each atom or ion. Note that the atoms and ions are not necessarily neutral. A Se ion has a mass number of 78 and a charge of −2 . Determine the number of neutrons, protons, and electrons in this ion. number of neutrons: 44 number of protons: 34 number of electrons: 36 An ion has a mass number of 65, 36 neutrons, and a charge of +1 . Identify the element symbol, and determine the number of protons and electrons in this ion. element symbol: Cu number of protons: 30 number of electrons: 29 An atom or ion has 43 neutrons , 36 protons, and 36 electrons. Identify the element symbol, and determine the mass number and charge for this atom or ion. element symbol: Au mass number: 79 charge: 0
Answer:
Check the explanation
Explanation:
1)
Atomic number of Se = 34
So, number of proton = 34
use:
charge = number of proton - number of electron
-2 = 34 - number of electron
number of electron = 36
number of neutron = mass number - atomic number
= 78 - 34
= 44
Answer:
44
34
36
2)
number of proton = mass number - number of neutron
= 65 - 36
= 29
29 is atomic number for Cu
use:
charge = number of proton - number of electron
+1 = 29 - number of electron
number of electron = 28
Answer:
Cu
29
28
3)
Atomic number is 36 for Kr
use:
charge = number of proton - number of electron
= 36 - 36
= 0
use:
mass number = number of proton + number of neutron
= 36 + 42
= 78
Answer:
Kr
78
0
If 120.4 grams of reactant completely breaks down (decomposes) to produce 106.4 grams of chlorine. What mass of nitrogen gas could be expected? *
Answer:
[tex]m_{nitrogen}=14g[/tex]
Explanation:
Hello,
In this case, since we are talking about a chemical reaction in which a compound having nitrogen and chlorine is decomposed into chlorine and nitrogen, we must remember that the law of conservation of mass must be obeyed, for that reason, we notice that the mass of the whole reactants must equal the mass of the whole products, as shown below:
[tex]m_{reactants}=m_{products}[/tex]
Next, we know there is only one single reactant and products are constituted by both chlorine and nitrogen:
[tex]m_{reactant}=m_{chlorine}+m_{nitrogen}[/tex]
In such a way, we can compute the mass of nitrogen as shown below:
[tex]m_{nitrogen}=m_{reactant}-m_{chlorine}=120.4g-106.4g\\\\m_{nitrogen}=14g[/tex]
Best regards.
Metamorphic rocks directly form from
Answer:
Metamorphic rocks are formed from pre-existing rock and sediment materials. They are formed when igneous, sedimentary, or other pre-existing metamorphic rocks are exposed to the heat and pressure as well as super-heated mineral-rich fluids. They are compacted together to form a new rock altogether. Metamorphism does not include the melting or liquefaction of the pre-existing rock. Instead, it compacts them and crushes them, pushing them together at extreme heat and pressure to form a new rock altogether composed of sedimentary, igneous, and other metamorphic rock. It's the rock hybrid of the geologic world.
Metamorphism is similar to when you squish playdough together, it doesn't form a new playdough color (unless you REALLY mixed that poor playdough together). It forms an amalgamation of different colors and patterns made from the other rock.
Taken from a paper I once wrote I explained this again:
"Metamorphic rocks are formed when pre-existing rocks and their minerals are compressed and altered by Earth’s internal processes; interior pressure, temperature (heat), and chemical reactions. The minerals and pre-existing rock necessary for the creation of metamorphic rock must then also be located deep underground if such processes are expected to make an impact and create a metamorphic rock."
PLEASEEEE help! BRAINLIEST to right answer!!!!
Answer:
D
Explanation:
No energy is lost during transforming into another because energy cannot be reated or destroyed
Answer:
i think is d
Explanation:
I'm not sure wait for a few more answers
Common additives to drinking water include elemental chlorine, chloride ions, and phosphate ions. Recently, reports of elevated lead levels in drinking water have been reported in cities with pipes that contain lead, Pb(s). When Cl2(aq) flows through a metal pipe containing Pb(s), some of the lead atoms oxidize, losing two electrons each, and aqueous chloride ions form. (a) Write a balanced, net-ionic equation for the reaction between Pb(s) , and Cl2(aq).
Answer:
See explaination
Explanation:
Balanced net ionic reaction.
Pb(s) + Cl2(g) ----- Pb2+ + 2Cl-
oxidation reaction :Pb(s) --- Pb2+ + 2e-
Reduction reaction:Cl2 + 2e- -----Cl-
Indicate the changes (increases, decreases, does not change) in its volume when the pressure undergoes the following changes at constant temperature and amount of gas. Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer. ResetHelp 1. The pressure increases to 6.0 atm. The volume The pressure increases to 6.0 a t m. The volume blank.. 2. The pressure drops to 0.40 atm. The volume The pressure drops to 0.40 a t m. The volume blank.. 3. The pressure remains at 2.0 atm. The volume The pressure remains at 2.0 a t m. The volume blank..
The question is missing information. Here is the complete question.
A gas at a pressure of 2.0 atm is in a closed container. Indicate the changes (if any) in its volume when the pressure undergoes the following changes at constant temperature and constant amount of gas. Match the words in the left with the column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.
1. The pressure increases to 6.0 atm. The volume ________
2. The pressure drops to 0.40 atm. The volume _________
3. The pressure remains at 2.0 atm. The volume _________
Answer: 1. Decreases
2. Increases
3. Does not change
Explanation: According to the Ideal Gas Law, Pressure, Volume and Temperature of an ideal gas is related, as the following: PV = nRT.
In this case, since temperature (T) and amount of gas (n) are constant, the Boyle's Law can be used.
The law states that the volume of a given gas, under the conditios of temperature and amount of it are constant, is inversely proportional to the applied pressure: P₁.V₁ = P₂.V₂
For case 1.)Initial P (P₁) = 2
Initial V (V₁) = V
Final P (P₂) = 6
P₁.V₁ = P₂.V₂
2.V = 6.V₂
V₂ = 1/3V
When the pressure increases to 6 atm, volume decreases by 1/3.
For case 2.)P₁ = 2
V₁ = V
P₂ = 0.4
2.V = 0.4V₂
V₂ = 5V
When pressure drops to 0.4 atm, volume increases by 5.
For case 3.)Since there are no change in the pressure, the volume is the same from the beginning, so does not change.
Gaseous butane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 42. g of butane is mixed with 150. g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
127 grams of carbon dioxide
Explanation:
We need to determine the chemical equation first. Butane has a chemical formula of [tex]C_4H_{10}[/tex], oxygen is [tex]O_2[/tex], carbon dioxide is [tex]CO_2[/tex], and water is [tex]H_2O[/tex]. The reactants are butane and oxygen and the products are carbon dioxide and water. So we write:
[tex]C_4H_{10}+O_2[/tex] ⇒ [tex]CO_2+H_2O[/tex]
But remember! We need to balance this. Currently, there are 4 carbon atoms (C), 10 hydrogen atoms (H), and 2 oxygen atoms (O) on the left, while there are 1 carbon atom (C), 2 hydrogen atoms (H), and 3 oxygen atoms (O) on the right. Let's place a coefficient of 4 in front of the carbon dioxide and a coefficient of 5 on the water, so that we have equal numbers of carbon and hydrogen atoms on each side:
[tex]C_4H_{10}+O_2[/tex] ⇒ [tex]4CO_2+5H_2O[/tex]
However, we need to ensure that there are equal numbers of O atoms, as well. On the left, we have 2 and on the right we have 13, so let's put a coefficient of 6.5 on the oxygen:
[tex]C_4H_{10}+6.5O_2[/tex] ⇒ [tex]4CO_2+5H_2O[/tex]
Finally, multiply everything by 2 to get whole number coefficients:
[tex]2C_4H_{10}+13O_2[/tex] ⇒ [tex]8CO_2+10H_2O[/tex]
Ah, now we can actually get to the problem!
We need to determine the limiting reactant, so let's convert the 42 g of butane and 150 g of oxygen into moles of any product, say, carbon dioxide. To convert to moles, we need to find the molar mass of each compound.
The molar mass of butane is 4 * 12.01 + 10 * 1.01 = 58.14 g/mol, while the molar mass of oxygen is 2 * 16 = 32 g/mol. We can now set up the equations:
[tex]42 gC_4H_{10}*\frac{1molC_4H_{10}}{58.14gC_4H_{10}} *\frac{8molCO_2}{2molC_4H_{10}} =2.8896molCO_2[/tex]
[tex]150 gO_2*\frac{1molO_2}{32gO_2} *\frac{8molCO_2}{13molO_2} =2.8846molCO_2[/tex]
Clearly, we see that 2.8846 < 2.8896, which means that oxygen is the limiting reactant. In other words, the most products can be made when the oxygen is all used up.
Now let's finally convert moles of carbon dioxide into grams by multiplying by its molar mass, which is 12.01 + 2 * 16 = 44.01 g/mol:
[tex]2.8846molCO_2*\frac{44.01gCO_2}{1molCO_2} =127gCO_2[/tex]
Notice that we have 3 significant figures because we had 3 significant figures at the start with 150. grams of oxygen.
~ an aesthetics lover
Draw the structure of a compound with the molecular formula CgH1002 that exhibits the following spectral data.
(a) IR: 3005 cm-1, 1676 cm-1, 1603 cm-1
(b) H NMR: 2.6 ppm (singlet, I = 3H), 3.9 ppm (singlet, I = 3H), 6.9 ppm (doublet, I = 2H), 7.9 ppm (doublet, I = 2H)
(c) 13C NMR: 26.2, 55.4, 113.7, 130.3, 130.5, 163.5, 196.6 ppm ?
Answer:
The answer you are looking for is A
Problem PageQuestion Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. An industrial chemist studying this reaction fills a 500. mL flask with 1.3 atm of sulfur dioxide gas and 4.1 atm of oxygen gas, and when the mixture has come to equilibrium measures the partial pressure of sulfur trioxide gas to be 0.91 atm. Calculate the pressure equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. Round your answer to 2 significant digits.
Answer:
SO₂: 0.39atm
O₂: 3.645atm
Explanation:
Based on the reaction:
2 SO₂(g) + O₂(g) → 2 SO₃(g)
2 moles of sulfur dioxide react per mole of oxygen to produce 2 moles of sulfur trioxide.
When the reaction occurs an comes to equilbrium, the partial pressure of each gas is:
SO₂: 1.3atm - 2X
O₂: 4.1atm -X
SO₃: 2X
Where X is the reaction coordinate.
As pressure at equilibrium of SO₃ is 0.91 atm:
0.91atm = 2X
Thus: X = 0.455atm.
Replacing, pressures at equilibrium of the gases are:
SO₂: 1.3atm - 2×0.455atm = 0.39 atm
O₂: 4.1atm -0.455atm = 3.645 atm
cis-1-Bromo-4-tert-butylcyclohexane and trans-1-bromo-4-tert-butylcyclohexane both react with sodium ethoxide in ethanol to form 4-tert-butylcyclohexene. Explain why the cis isomer reacts much more rapidly than the trans isomer. Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.
Answer:
See explanation below
Explanation:
In order to explain this, is neccesary to draw both confomers, the cis and trans, but in the chair conformation, because in that way we can see much better the bonds and the reason of why the cis reacts faster than trans.
As you can see in picture attached, the more stable conformer is the one where the H and Br are in the axial position, and the tert butyl group in equatorial position. In these positions, the cis isomer can undergo an E2 reaction, and the ethoxide would have no problem to substract the hydrogen atom from the molecule to eliminate the Bromide. This is because the t-butyl group in equatorial position, is not exerting steric hindrance, therefore is faster.
In the case of the trans, the t-butyl group is in the axial position as well as the hydrogen and bromide, therefore, when the E2 reaction undergoes, the hydrogen is substracted by ethoxide, but it will be slow because the t.butyl group exerts steric hindrance in the axial positions, therefore, the hydrogen will be substracted slower than in the cis position. This is the main reason for the cis to be faster.
As for the second part of the question, which will be the answer of the whole question, see picture attached 2 for the whole sentence, and the match of the words is the following:
1. Axial
2. More
3. Blank (No word there)
4. less
5. Blank
6. Cis
7. Trans
8. Cis
Each of the the 11 body systems:
A) Are interchangeable
B) Depends on others to function
C) Performs a single task
D) Is controlled by the lungs
Answer:
Depends on others to function
Explanation:
What amount of heat will raise the temperature of 78g liquid water from 20 C to 80 C?
Answer:
19656J
Explanation:
Step 1:
Data obtained from the question.
Mass (M) = 78g
Initial temperature (T1) = 20°C
Final temperature (T2) = 80°C
Change in temperature (ΔT) = T2 – T1 =
80°C – 20°C = 60°C
Specific heat capacity (C) = 4.2J/g°C
Heat (Q) =...?
Step 2:
Determination of the heat required for the reaction.
Q = MCΔT
Q = 78 x 4.2 x 60
Q = 19656J
Therefore, 19656J of heat is required.
A sample of gas occupies a volume of 120.0mL at a pressure of 0.75atm and a temperature of 295K. What will the volume be at a pressure of 1.25
atm and a temperature of 345K?
A)48mL
B)84mL
C)8mL
D)4mL
Answer:
A) 84 mL
Explanation:
use general gas equation P1×V1 / T1 = P2×V2/T2
rearrange the formula and solve for V2,it should give you V2= 84mL
Answer:
[tex]\large \boxed{\text{B) 84 mL}}[/tex]
Explanation:
We can use the Combined Gas Laws to solve this problem .
[tex]\dfrac{p_{1}V_{1} }{T_{1}} = \dfrac{p_{2}V_{2}}{T_{2}}[/tex]
Data
p₁ = 0.75 atm; V₁ = 120.0 mL; T₁ = 295 K
p₂ = 1.25 atm; V₂ = ?; T₂ = 345 K
Calculations
[tex]\begin{array}{rcl}\dfrac{p_{1}V_{1} }{T_{1}} & = & \dfrac{p_{2}V_{2}}{T_{2}}\\\\\dfrac{\text{0.75 atm $\times$ 120.0 mL}}{\text{295 K}} & = & \dfrac{\text{1.25 atm} \times V_{2}}{\text{345 K}}\\\\\text{0.305 mL} & = & \text{0.003 523V}_{2}\\V_{2}& =& \dfrac{\text{0.305 mL}}{0.003523}\\\\& = & \textbf{84 mL}\\\end{array}\\\text{The new volume of the gas is $\large \boxed{\textbf{84 mL}}$}[/tex]
is silver malleable because the valence electrons are strongly attracted to the nucleus
