Answers
Answer:
q1..no.2 and 4 are aromatic
Related Questions
g A chemistry student needs of thiophene for an experiment. She has available of a w/w solution of thiophene in benzene. Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button. Round your answer to significant digits.
Answers
The given question is not complete, the complete question is:
A chemistry student needs 5.00 g of thiophene for an experiment. She has available 0.50 kg of a 28.7% w/w solution of thiophene in benzene, Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button Be sure your answer has the correct number of significant digits. X
Answer:
The correct answer is 17.4 grams.
Explanation:
As mentioned in the given question, 28.7 percent w/w solution thiophene in benzene shows that,
(wt. of thiophene / wt. of thiopene + benzene) * 100 = 28.7
0.50 kg of the solution indicates that it is 500 grams of the solution.
Therefore, the amount of thiophene found in the 500 grams of the solution is,
500 g * 28.7 / 100 = 143.5 gm
Thus, 143.5 grams of thiophene is found 500 grams of the solution.
Now, 1 gram of thiophene will be in 500/143.5 of solution.
Therefore, 5 grams of thiophene will be in 500/143.5 * 5 g of the solution = 17.42 grams of the solution.
Hence, the mass of the solution to be used by the student in the given case will be 17.4 grams.
It takes 300 N to move a box 10 meters in 10 seconds. How much power is
required?
A. 30,000 W
B. 100 W
C. 3,000 J
D. 300 W
Plz help
Answers
Answer:
Power, P = 300 W
Explanation:
We have,
Force acting on the box to take it is 300 N
It is moved to a distance of 10 m in 10 seconds
It is required to find the power required to move the box. The rate at which work is done is called power required by an object. It can be given by the formula as follows :
[tex]P=\dfrac{W}{t}\\\\P=\dfrac{Fd}{t}\\\\P=\dfrac{300\times 10}{10}\\\\P=300\ W[/tex]
So, the power required is 300 W.
What is the hydronium ion concentration of a 0.100 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociation of acetic acid is: CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq) What is the hydronium ion concentration of a 0.100 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociation of acetic acid is: CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq) 1.3 × 10-2 M 4.2 × 10-2 M 1.3 × 10-3 M 4.2 × 10-3 M
Answers
Answer:
1.3×10⁻³ M
Explanation:
Hello,
In this case, given the dissociation reaction of acetic acid:
[tex]CH_3CO_2H(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + CH_3CO_2^-(aq)[/tex]
We can write the law of mass action for it:
[tex]Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}[/tex]
Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change [tex]x[/tex] due to the dissociation extent, we are able to rewrite it as shown below:
[tex]1.8x10^{-5}=\frac{x*x}{0.100-x}[/tex]
Thus, via the quadratic equation or solve, we obtain the following solutions:
[tex]x_1=-0.00135M\\x_2=0.00133M[/tex]
Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.
Regards.
Answer:
1.3×10^-3 M
Explanation:
Step 1:
Data obtained from the question:
Equilibrium constant (Ka) = 1.8×10^-5
Concentration of acetic acid, [CH3COOH] = 0.100 M
Concentration of hydronium ion, [H3O+] =..?
Step 2:
The balanced equation for the reaction.
CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq)
Step 3:
Determination of concentration of hydronium ion, [H3O+].
This can be obtained as follow:
Ka = [H3O+] [CH3CO2-] / [CH3CO2H]
Initial concentration:
[CH3COOH] = 0.100 M
[H3O+] = 0
[CH3CO2-] = 0
During reaction
[CH3COOH] = – y
[H3O+] = +y
[CH3CO2-] = +y
Equilibrium:
[CH3COOH] = 0.1 – y
[H3O+] = y
[CH3CO2-] = y
Ka = [H3O+] [CH3CO2-] / [CH3CO2H]
1.8×10^-5 = y × y / 0.1
Cross multiply
y^2 = 1.8×10^-5 x 0.1
Take the square root of both side
y = √(1.8×10^-5 x 0.1)
y = 1.3×10^-3 M
[H3O+] = y = 1.3×10^-3 M
Therefore, the concentration of the hydronium ion, [H3O+] is 1.3×10^-3 M
Helium occupies a volume of 3.8 L at –45°C. What was its initial temperature when it occupied 8.3 L?
Answers
Answer:
98.3 gradius Celsius
Explanation:
This problem is solved using the Ideal Gas Equation
pV = nRT
...
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
How do you calculate the number of protons, neutrons, and electrons in an element?
Answers
Answer:
The first thing you will need to do is find some information about your element. Go to the Periodic Table of Elements and click on your element. If it makes things easier, you can select your element from an alphabetical listing.
Number of Protons = Atomic Number
Number of Electrons = Number of Protons = Atomic Number
Number of Neutrons = Mass Number - Atomic Number
For krypton:
Number of Protons = Atomic Number = 36
Number of Electrons = Number of Protons = Atomic Number = 36
Number of Neutrons = Mass Number - Atomic Number = 84 - 36 = 48
Explanation:
hope this helps, have a good day :-)
if a sample of gas at 25.2 c has a volume of 536mL at 637 torr, what will its volume be if the pressure is increased to 712 torr?
Answers
PV= RTn
T= 25.2°C = 298.2 K
P1= 637 torr = 0.8382 atm
V1= 536 mL = 0.536 L
:. R=0.082 atm.L/K.mol
:. n= (P1V1)/(RT) = ((0.8382 atm) x (0.536 L))/
((0.082 atmL/Kmol) x (298.2K))
:. n= O.0184 mol
Then,
P2= 712 torr = 0.936842 atm
V2 = RTn/P2 = [(0.082atmL/
Kmol) x (298.2K) x (0.0184mol) ]/(0.936842atm)
:.V2 = 0.4796 L
OR
V2 = 479.6 ml
If I add 50 mls of water to 300 mls of 0.6M KNO3 solution, what will be the molarity of the diluted solution?
Answers
Answer:
[tex]M_2=0.51M[/tex]
Explanation:
Hello,
In this case, for this dilution process, we understand that the moles of the solute (potassium nitrate) remain unchanged upon the addition of diluting water. However, the resulting or final volume includes the added water as shown below:
[tex]V_2=300mL+50mL=350mL[/tex]
In such a way, we are able to relate the solution before and after the dilution by:
[tex]V_1M_1=V_2M_2[/tex]
Hence, we solve for the final molarity as:
[tex]M_2=\frac{M_1V_1}{V_2}=\frac{0.6M*300mL}{350mL}[/tex]
Best regards.
[tex]M_2=0.51M[/tex]
PbCl2+ AgNO3------>Pb(NO3)2+ AgCl
Decomposition
Synthesis
Double displacement
Exothermic
Answers
Answer:
Option C
Explanation:
A double displacement reaction is the one in which two chemical compounds having a cation and anion in each exchange their positive and negative ions thereby forming new compounds or products.
Here,
The first compound [tex]PbCl_2[/tex] has a positive ion [tex]Pb[/tex] and negative ion [tex]Cl^-[/tex]
Like wise the second compound [tex]Ag(NO_3)[/tex] has a positive ion [tex]Ag[/tex] and negative ion [tex]NO_3[/tex]
The new compounds will be formed when cation of one compound attaches with the anion of other compound. Hence the new compounds are
[tex]Pb(NO_3)_2[/tex]
[tex]AgCl[/tex]
This is example of double displacement reaction.
Option C is correct
A 125 g sample of strontium was heated from 0°C to 20°C. It absorbed 750 J of energy. What is the specific heat capacity of iron?
Answers
Answer:
Specific heat capacity of iron (C) = 0.3 J/GK
Explanation:
Given:
Mass of sample (m) = 125 gram
Change in heat (ΔT) = 20°C - 0°C = 20°C
Absorbed energy (ΔE) = 750 J
Find:
Specific heat capacity of iron (C) = ?
Computation:
⇒ Specific heat capacity of iron (C) = ΔE / [mΔT]
⇒ Specific heat capacity of iron (C) = 750 / [125 × 20]
⇒ Specific heat capacity of iron (C) = 750 / [2,500]
⇒ Specific heat capacity of iron (C) = 0.3 J/GK
Answer:
Specific heat capacity of iron (C) [tex]= 0.3[/tex] J/g°C
Explanation:
As we know that
Specific heat capacity of iron (C) [tex]=\frac{\delta E}{ [m* \delta T]}[/tex]
Where [tex]\delta E[/tex] represents the change in the energy
m represents the mass of the sample and
[tex]\delta T[/tex] represents the change in temperature.
Given:
Mass of sample (m) [tex]= 125[/tex] gram
Change in heat ([tex]\delta T[/tex] ) [tex]20 - 0 = 20[/tex]
Absorbed energy ([tex]\delta E[/tex])[tex]= 750[/tex] J
Substituting the given values in above equation, we get -
Specific heat capacity of iron (C)
[tex]= \frac{750}{125*20}[/tex]
Specific heat capacity of iron (C) [tex]= 0.3[/tex] J/g°C
Which factor would slow down a chemical reaction? (Choose all that apply)
A)Adding an inhibitor
B)Decreasing temperature
C)Decreasing particle size
D)Increasing particle size
Answers
Answer:
(decreasing particle size) C
Explanation: That is one of the answers, if there are more I am sorry.
A gas in a piston–cylinder assembly undergoes a compression process for which the relation between pressure and volume is given by p = AV2 + BV-2 (p is in bar and V is in m3). The initial volume is 0.1 m3, and the initial pressure is 1 bar. The final volume is 0.04 m3, and the final pressure is 2 bar. Determine:
Answers
Answer:
1.
[tex]A=69.8\frac{bar}{m^6}\\\\ B=0.00302bar*m^6[/tex]
2. [tex]W=-8.2kPa[/tex]
Explanation:
Hello,
1. In this case, for the given p-V equation, one could use the two states to form a 2x2 linear system of equations in terms of A and B:
[tex]\left \{ {{0.1^2A+0.1^{-2}B=1} \atop {0.04^2A+0.04^{-2}B=2}} \right.[/tex]
[tex]\left \{ {{0.01A+100B=1} \atop {0.0016A+625B=2}} \right[/tex]
Whose solution by any method for solving 2x2 linear system of equations (elimination, reduction or substitution) is:
[tex]A=69.8\frac{bar}{m^6}\\\\ B=0.00302bar*m^6[/tex]
2. Now, for us to compute the work, we must first compute n, as the power relating the pressure and volume for this process:
[tex]P_1V_1^n=P_2V_2^n\\\\\frac{P_1}{P_2}=(\frac{V_2}{V_1} )^n\\\\\frac{1bar}{2bar}= (\frac{0.04m^3}{0.1m^3} )^n\\\\0.5=0.4^n\\\\n=\frac{ln(0.5)}{ln(0.4)} =0.7565[/tex]
Now, we compute the work:
[tex]W=\frac{P_2V_2-P_1V_1}{1-n} =\frac{2bar*0.04m^3-1bar*0.1m^3}{1-0.7565} \\\\W=-0.082bar*m^3*\frac{1x10^2kPa}{1bar}\\ \\W=-8.2kPa[/tex]
Regards.
A container is filled with 10 mol of gas and the pressure (Pi) is measured. If 5 mol are removed, what is the new pressure (Pf)?
Answers
Answer:
1/2 of the Pi
Explanation:
PV = nRT
we are going to assume the only things changing are pressure and number of mols, so we change the formula and substitute the variables to make it what we are looking for
[tex]\frac{Pi}{ni} = \frac{Pf}{nf}[/tex]
then we will assume Pi as 1 as it is not given, so we can state it easier
[tex]\frac{1atm}{10mol} = \frac{xatm}{5mol}[/tex]
then either cross multiply or just work it out to be
[tex]\frac{1}{2}[/tex] which we can say as "half of the initial pressure" as no number is given for initial pressure
When you add a controlled amount of substance known as an impurity to a pure semiconductor, its conductivity increases. This process is known as doping. The addition of an impurity can increase or decrease the number of available electrons. If the number of electrons is increased, the extra electrons conduct electricity. If the number of electrons is decreased, a vacant hole is created. The adjacent electron enters the vacant hole and conducts electricity. Thus, it seems like the holes act as charge carriers. They are considered to be positive charge carriers. Depending upon the charge carriers that conduct electricity, there are two types of semiconductors: p-type semiconductors and n-type semiconductors.Which of the following statements are correct with respect to semiconductors?
a) The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors.
b) The conductivity of semiconductors can be increased by the doping process.
c) As the temperature increases, the conductivity of semiconductors decreases.
d) The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors.
e) Holes are charge carriers in p-type semiconductors.
f) Electrons are charge carriers in n-type semiconductors.
Answers
Answer:
See explaination
Explanation:
1. The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors: Wrong
The addition of 3A group elements inreases the conductivity and make them extrinsic semiconductors( p-type)
2. The conductivity of semiconductors can be increased by the doping process.: Correct
3.As the temperature increases, the conductivity of semiconductors decreases.. wrong
As the temperature increases, the conductivity of semiconductors increases.
4. The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors: Correct : They will create n-type semicoductor.
5.Holes are charge carriers in p-type semiconductors: Correct
6. Electrons are charge carriers in n-type semiconductors: Correct
If you start with 64g of a radioactive element how many half-lives would occur before 8g remain?
Answers
Answer:
3 half-lives
Explanation:
The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.
Let's suppose we start with 64 g of the radioactive element.
After 1 half-life, the mass of the element will be 32 g.After 2 half-lives, the mass of the element will be 16 g.After 3 half-lives, the mass of the element will be 8 g.3. Infer A forgotten ice pop lies melting on a deck on a hot summer day. What is the direction of heat flow as the ice pop melts?
Is the process endothermic or exothermic? Explain.
Answers
Answer:
Endothermic. The energy is flowing into the molecules causing them to break apart and the ice pop change state.
Answer:
Yes, an autumn day isn’t cold enough to keep an ice pop at freezing temperatures.
please do this guys i need a lot of help please!
Answers
Answer:
the European countries grew together.
Explanation:
Europe saw human inflows from east and southeast.
the Roman Empire came to dominate the entire Mediterranean basin.
European politics from 1947 to 1989 made the European countries grew together.
SCIENCE QUESTION:
The picture below shows a satellite image of Earth from outer space.What is labeled “White” on the satellite image of Earth?
A. gas in Earth's atmosphere, which keeps Earth's temperature moderate, cycles fluids, and prevents most objects from impacting Earth's surface
B. gravity, which holds all living organisms to Earth, pulls water from clouds, and keeps Earth circulating around the Sun
C. a magnetic field, which controls the movement of water in Earth's water cycle
D. atmospheric ice crystals, which never melt and keep Earth's temperature coo
Answers
Answer:
C
Explanation:
The reflection if sunlight on the water makes the water look silver,gray,white
Dysphagia is the name of a disorder that disrupts
А
the swallowing reflex
B
the absorption of essential nutrients
acid levels in the stomach
C
D
the stomach lining
Answers
Answer:
A. The Swallowing reflex
Explanation:
Dysphagia Is a a condition that makes swallowing difficult.
А
the swallowing reflex
How to make isopropyl alcohol
Answers
Answer:
.It is easily synthesized from the reaction of propylene with sulfuric acid, followed by hydrolysis. Isopropyl alcohol (2-propanol) is made by indirect hydration of propylene (CH2CHCH3).… In some cases the hydration of propylene is carried out in one step, using water and a catalyst at high pressure.
Hope it'll help!
stay safe:)
6.) (5 points) Assume you have a system with a fixed pH of 4.0. It is well buffered and therefore the pH will not change. What is the predominant state of a molecule with a dissociable proton with a pKa of 5.2 if it is introduced to that system (protonated or deprotonated)
Answers
Answer:
Dissociated state is the predominant one
Explanation:
When a molecule with pKa of 4.52 is in an aqueous solution at pH = 4.0, follows the H-H equation, thus:
pH = pKa + log₁₀ [A⁻] / [HA]
Where [A⁻] is the dissociated state and [HA] represents the protonated state
Replacing:
4.0 = 5.2 + log₁₀ [A⁻] / [HA]
-1.2 = log₁₀ [A⁻] / [HA]
0.063 = [A⁻] / [HA]
[HA] = 16 [A⁻]
That means you have 16 times more [HA] than [A⁻] and the dissociated state is the predominant one
I'll give you 100 points
Which are evidence of seafloor spreading? Select three options. A.molten material B.magnetic stripes C.continent material D.drilled core samples E.ocean water samples
Answers
B. Magnetic stripes
D. Drilled core samples
What is the molarity of sodium hydroxide solution made by combining 2.0 L of 0.60
NaOH With 495 mL 3.0 M NaOH? Assume the volumes of the two solutions to be additive___M
Answers
Answer:
[tex]M=1.1M[/tex]
Explanation:
Hello,
In this case, since we are mixing two NaOH solutions, the first step is to compute the total moles once the mixing is done, by using the volumes and concentrations of each solutions and subsequently adding them:
[tex]n_T=2.0L*0.60\frac{mol}{L}+495mL*\frac{1L}{1000mL}*3.0\frac{mol}{L}= 2.7molNaOH[/tex]
Next, we compute the total volume by adding the volume of each solution:
[tex]V_T=2.0L+495mL*\frac{1L}{1000mL}= 2.495L[/tex]
Finally, we compute the molarity of the resulting solution by the division between the total moles and the total volume:
[tex]M=\frac{2.7mol}{2.495L}\\ \\M=1.1M[/tex]
Best regards.
Write and balance the double replacement reaction between barium sulfate and titanium (II) oxide.
Answers
Answer:
BaSO4(aq) + TiO(aq) —> BaO(aq) + TiSO4(aq)
Explanation
The equation for the reaction between barium sulfate and titanium (II) oxide is given below:
BaSO4 + TiO —>
In solution, the reactants will dissociates as follow:
BaSO4(aq) —> Ba^2+(aq) + SO4^2-(aq)
TiO(aq) —> Ti^2+(aq) + O^2-(aq)
The double displacement reaction will occur as follow:
Ba^2+(aq) + SO4^2-(aq) + Ti^2+(aq) + O^2-(aq) —> Ba^2+O^2-(aq) + Ti^2+SO4^2-(aq)
We can see that a double displacement reaction occurred as there is a double exchange of ions in the solution. The elemental equation is given below:
BaSO4(aq) + TiO(aq) —> BaO(aq) + TiSO4(aq)
Question 13: Consider the strength of the Hβ absorption line in the spectra of stars of various surface temperatures. This is the amount of light that is missing from the spectra because Hydrogen electrons have absorbed the photons and jumped from level 2 to level 4. How do you think the strength of Hβ absorption varies with stellar surface temperature?
Answers
Answer:
The absorption and strength of the H-beta lines change with the temperature of the stellar surface, and because of this, one can find the temperature of the star from their absorption lines and strength. To better comprehend, let us look into the concept of the atom's atomic structure.
Atoms possess distinct energy levels and these levels of energy are constant, that is, the temperature has no influence on it. However, temperature possesses an influence on the electron numbers found within these levels of energy. Therefore, to generate an absorption line of hydrogen in the electromagnetic spectrum's visible band, the electrons are required to be present in the second energy level, that is when it captivates a photon.
Therefore, after captivating the photons the electrons jump from level 2 to level 4, which shows that there is an increase in the stellar surface temperature and at the same time one can witness a decline in the strength of the H-beta lines. In case, if the temperature of the surface increases too much, then one will witness no attachment of electron with the hydrogen atom and thus no H lines, and if the temperature of the surface becomes too low, then the electrons will stay in the ground state and no formation of H lines will take place in that condition too.
Hence, to generate a very robust H line, after captivating photons the majority of the electrons are required to stay in the second energy level.
.The pH is 3. What is [H+]? *
1 point
0.001
0.01
100
1000
Answers
Answer:
0.001 M
Explanation:
The pH scale is used to determine the acidity or basicity of a solution.
If pH < 7, the solution is acid.If pH = 7, the solution is neutral.If pH > 7, the solution is basic.The pH is related to the concentration of hydrogen ions through the following expression.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog - 3 = 0.001 M
When Mrs. Green describes the physical properties of matter she said that physical properties often concern changes in state, One
physical property that does not describe a change in state is
A)
density
B)
evaporation
C)
freezing
D)
melting
Answers
Answer:
density
Explanation:
Density is an important measurement. It has an unit: g/mL or kg/L, ...
Evaporation, freezing, melting are the processes in which the substances change their states. Other processes are: condensation, sublimation, deposition.
...
Hope this answer can help you. Have a nice day!
At constant temperature and moles, what happens to the pressure of a gas
as the volume of that gas increases? *
Answers
Answer:
Avagadro's Law- Gives the relationship between volume and amount of gas in moles when pressure and temperature are held constant. If the amount of gas in a container is increased, the volume increases. ... This means more impacts on the walls of the container and an increase in the pressure.
Explanation:
What is the symbol for the entity that has 17 protons, 20 neutrons, and 18 electrons?
Answers
hEy!!!
Chlorine(CL) is the symbol for the entity that has 17 protons,20 neutrons and 18 electrons.
Hope it will be helpful to you...
Answer:chlorine
Explanation:
What is the total amount of energy needed to heat 22.6 g of titanium from 1420oC to 1590oC in joules?
Answers
Answer:
[tex]Q=2091J=2.091kJ[/tex]
Explanation:
Hello,
In this case, the formula we use to compute the heat Q by increasing the temperature, in terms of the mass and the heat capacity is:
[tex]Q=mCp(T_2-T_1)[/tex]
Titanium's heat capacity is 0.544284 J/g°C, thus, the for such temperature increase, the heat results positive as shown below:
[tex]Q=22.6g*0.544284\frac{J}{g^oC}*(1590^oC-1420^oC) \\\\Q=2091J=2.091kJ[/tex]
Best regards.
Claims • Evidence • Reasoning Make
a claim about ways people can stay safe
during storms with high wind and heavy
rains. Summarize evidence to support the
claim and explain your reasoning.
Answers
Answer:
the claim is that when people avoid storms they hide in any secret place in there house
Explanation:
when people do that they don't even have to worry about a single thing that will happen to them
