Answers
Answer:I'm going to give some fictitious values just so that we can get some perspective on the matter.
Let's say that the surface temperature of our sun is 10, the surface temp of the bigger star- the red giant formed from leaving the main sequence, has a temp of 0.2. of that- 2.
We can also say that the radius of our sun is 10, and the radius of the red giant is 1000. (100 times more)
Using the equation:
L
=
σ
A
T
4
σ
= The Stefan-Boltzmann constant =
5.67
×
10
−
8
But we can ignore the constant, as we are only interested in a ratio of these values.
L
S
u
n
=
4
π
(
10
)
2
×
10
4
=
1.26
×
10
7
L
S
t
a
r
=
4
π
(
1000
)
2
×
2
4
≈
2.01
×
10
8
2.01
×
10
8
1.26
×
10
8
≈
16
So the newly formed, red giant star is almost 16 times more luminous than the sun. This is owing to the increased surface area of the star due to the massively increased radius.
A small sidenote:
There is an equation that might be useful for comparing the radii, temperature and luminosity of main sequence stars. As red giants are not on the main sequence it could not be used here, but if you stumble across a question where they ask you to find the radius, luminosity or temperature given the other two, you can relate it to the sun's characteristics:
r
s
t
a
r
r
s
u
n
=
√
L
s
t
a
r
L
s
u
n
×
(
T
s
u
n
T
s
t
a
r
)
2
(I know, it's not a beauty to look at- but it works)
Where
X
s
u
n
is the radius, temperature, and luminosity of the sun. These are not often given in numerical values, but this equation serves well when asked to find e.g the radius of a star, in solar radii given that a star is twice as luminous and has 5 times the temperature of that of the sun.
Hence:
T
s
t
a
r
=
5
T
s
u
n
L
s
t
a
r
=
2
L
s
u
n
r
s
t
a
r
r
s
u
n
=
√
2
L
s
u
n
L
s
u
n
×
(
T
s
u
n
5
T
s
u
n
)
2
(cancel the common terms)
r
s
t
a
r
r
s
u
n
=
√
2
×
(
1
5
)
2
r
s
t
a
r
≈
0.057
r
s
u
n
(divide both sides by 0.0057)
17.5
r
s
t
a
r
≈
r
s
u
n
So the star's radius is almost 17.5 times that of the sun.
Hopefully, you find this info useful!
Explanation:
Related Questions
Which is the most soluble substance listed
Answers
what is the effect of heat and light on chemical reaction
Answers
In Universe L , recently discovered by an intrepid team of chemists who also happen to have studied interdimensional travel, quantum mechanics works just as it does in our universe, except that there are four d orbitals instead of the usual number we observe here. Use these facts to write the ground-state electron configurations of the third and fourth elements in the first transition series in Universe L .
Answers
Answer:
See explanation
Explanation:
The third element in the first transition series is Vanadium
The fourth element in the first transition series is chromium
Given that we have four d orbitals in universe L instead of five as we have on earth;
The electronic configuration of Vanadium in universe L is;
Ar 3d3 4s2
The electronic configuration of chromium in universe L is;
[Ar] 3d4 4s2
Are the gas laws affected depending on whether you use heavy gas particles or light gas particles? If anything, what is affected by the size of the molecule?
Answers
Answer:
yes
Explanation:
Yes, size of molecule has greatly affected the gas law.
The gas laws affected depending on whether we use heavy gas particles or light gas particles because the heavy gas particles can't move faster as light gas particles with the increase of temperature.
If the temperature is increased, the gas particles move faster due to absorb of heat energy so they hit the walls of the container. This causes the pressure to rise. The pressure of a gas also increases when the volume of container in which it is placed is decreased. Bigger the molecule size, the stronger the intermolecular forces, so the molecule has higher melting and boiling points so we can conclude that big size molecule greatly affected the gas law.
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Practice Problem 12.39 Partially correct answer. Your answer is partially correct. Try again. Acid-catalyzed hydration of 1-methylcyclohexene yields two alcohols. The major product does not undergo oxidation, while the minor product will undergo oxidation because the major product is Entry field with incorrect answer 2-methylcyclohexanol , which is a Entry field with incorrect answer secondary alcohol. These alcohols do not generally undergo oxidation. The minor product (Entry field with incorrect answer 1-methylcyclohexan-2-ol ) is asecondary alcohol and can undergo oxidation to yield a(n)
Answers
Answer:
See explanation and image attached
Explanation:
The acid-catalyzed hydration of 1-methylcyclohexene proceeds by an SN1 mechanism. The reaction involves the formation of carbocations.
Two carbocations are formed leading to the major and minor products. The major product is obtained from the tertiary (more stable) carbocation while the minor product is obtained from the secondary (less stable carbocation).
Tertiary alcohols are not oxidized, hence the major product does not undergo oxidation. However, secondary alcohols are oxidized to ketones.
Lesson Question: What is the effect of
pressure on the volume of a gas?
To answer this question, you used weight to
change the pressure of the gas and
measured the
resulting changes to the gas's volume.
COMPLETE
The amount of gas (in terms of moles, mass, and
molecules):
Answers
Answer:
pressure
volume
was constant
Boyle's
Explanation:
Answer:
the first one is pressure &volume the second one is was constant the third one is Boyle's
Explanation:
what is the effect of heat and light on chemical reaction
Answers
Answer:
Exothermic reactions release heat and light into their surroundings. For example, combustion reactions are usually exothermic. In exothermic reactions, the products have less enthalpy than the reactants, and as a result, an exothermic reaction is said to have a negative enthalpy of reaction.
Answer:
Is it fire onn a bottle?
Explanation:
Because I thought that if you shine light ona ANYTHING plastic, the chemical reaction is a little fire.
Which statement describes the movement of the medium by a transverse wave?
A. at an obtuse angle to the wave
B. parallel to the wave
C. at a right angle to the wave
D. at an acute angle to the wave
Answers
Answer:
A
Explanation:
But I'm not sure just my instinct
The statement that described the movement of the medium via the transverse wave should be that it should be parallel to the wave.
What is a transverse wave?It is the waves in which the motion considered all the points that should be on the wave oscillate along the paths at the right angles with respect to the wave of the direction. An example of this kind of wave should be electromagnetic, etc. Here, the movement should be parallel to the wave.
Hence, the correct option is b.
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A heterogeneous ore mixture contains 35.0 % In2O3 by mass. How many tons of the ore must be mined to provide 325.0 kg of indium metal? (2000 lb = 1 ton, assume exact)
Answers
Answer:
1.2375 ton of ore
Explanation:
Mass of indium = 325
Formula = In2O3
Molar mass = 277.64 g/mol
Molar mass of indium = (2*114.8)g
229.6 indium is in 277.64 of In2O3
Mass of In2O3 required = 277.64/229.6 x 325
= 392.94kg
35 % In2O3 in ore
For 35 kg = 100 kg required
For 392.94,
100/35 x 392.94
= 1122.686 kg
1122.68 x 2.2
= 2469.9 pounds
2469.9/200
= 1.235 tons of ore
Gold is yellow, shiny, smooth, and is found in the ground. A geologist finds a material that she thinks may be gold. Which of the following tests would reveal that
the material is not gold and not an element?
A. Its density is different from that of gold.
B. Its melting point is different from that of gold.
C. The material is composed of two different substances.
D. Its boiling point differs from that of gold.
Answers
how much energy must be released by 50.0 g of steam to decrease its temperature from 125.0 degrees Celsius to 100.0 degrees Celsius ?
Answers
Answer:
5250 Joules
Explanation:
Mass = 50g
Initial Temperature = 125.0 degrees Celsius
Final Temperature = 100 degrees Celsius
Temperature change = Final - Initial = 100 - 125 = -25
Heat = ?
These quantities are related by the equation;
H = mCΔT
where c = specific hear capacity = 4.2 J/g°C
H = 50 * 4.2 * (-25)
H = -5250 J (The negative sign is because heat is being released)
Which is correct order of the weather observed with each cloud type from 1 to 4?
A. Rain, thunderstorm, snow, fair
B. Light rain, fair, thunderstorm, fair
C. Light rain, thunderstorm, fair, fair
D. Hail, lightning, thunderstorm, fair
Answers
Answer:i thinks its A
Explanation:but who knows
Choose the more metallic element from each pair.
a . Sr or Sb,
b. As or Bi,
c. Cl or O,
d. S or As
Answers
Answer:
c
Explanation:
CI or O
Carla Vista Company has the following information available for September 2020.
Unit selling price of video game consoles $410
Unit variable costs $328
Total fixed costs $36,900
Units sold 600
Compute the unit contribution margin.
Unit contribution margin enter the unit contribution margin
Prepare a CVP income statement that shows both total and per unit amounts.
Compute Carla Vista’ break-even point in units.
Break-even point in units enter Break-even point in units units
Prepare a CVP income statement for the break-even point that shows both total and per unit amounts.
The more metallic element pair is Cl or O. Therefore, option C is correct.
What is metallic element ?Except for hydrogen, which is a nonmetal, the elements are arranged in a triangle with the metals to the left, the nonmetals to the right, and the metalloids to the immediate right of the triangle.
Metal atoms are bound together by metallic bonds to form solids known as metallic solids. Metal solids include things like copper, gold, and zinc, for instance. Since cesium is the last naturally occurring alkali metal, it has the most metallic characteristics.
The non-metal components, like as rock and rubbish, are subsequently removed from the ore during processing. The subsequent melting and combining of various metal components yields metal alloys. A solid metal alloy substance is produced when the freshly combined metal compound has cooled.
Thus, option C is correct.
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What is the formula for Pentasulfur heptaoxide
Answers
Answer:
S5O7
Explanation:
g When water and perchloric acid (HClO4) are mixed, heat is released. The resulting solution is not an ideal solution, in terms of Raoult’s Law. How should the boiling point and the vapor pressure of a solution of HClO4 in H2O differ from what is expected for an ideal solution? A) boiling point higher than expected, vapor pressure lower than expected B) boiling point higher than expected, vapor pressure higher than expected C) boiling point lower than expected, vapor pressure lower than expected D) boiling point lower than expected, vapor pressure higher than expected E) boiling point and vapor pressure are both the same as expected for an ideal solution
Answers
Answer:
A) boiling point higher than expected vapor pressure lower than expected.
Explanation:
When water is introduced with heat it vaporize at a temperature of 100 degree centigrade. When hydrochloric acid is added to the water its boiling point of water increases slightly. The difference in the boiling point is due to the presence of heavier molecules in acid.
Consider the reaction between a solution of molecule A and a solid block of molecule B. In general, for a reaction to occur, the reactant molecules must be in contact with each other. Therefore, increasing the frequency of collisions between A and B molecules allows the reaction to occur more quickly. Identify the change in reaction condition that will increase the frequency of the molecular collisions.
Answers
Answer:
Decreasing the volume of solvent in the solution of molecule A
Explanation:
We know that one of the factors that affect the rate of reaction is the concentration of the reactants. The greater the concentration of reactants, the faster the rate of reaction (the greater the frequency of collision between reactants).
Hence, when we decrease the volume of solvent in the solution of molecule A, the concentration of the solution increases and consequently more particles of molecule A are available to collide with particles of molecule B resulting in a higher rate of reaction.
what is used to create motion
Answers
Answer:
These forces make objects change their motion or movement , the act of going from one place to another.
Explanation:
The hydrolysis of adenosine triphosphate (ATP) is represented by the equation below. This reaction is critically important in cellular biology, but the reaction itself proceeds at a very slow rate. Based on the information given, which of the following best explains why an enzyme (biological catalyst) is required for the reaction to occur at a faster rate?
ATP+ H2O ADP+ Pi
ΔG= -30.5Kj/mol
a. Because ΔG < 0, the hydrolysis of ATP is not thermodynamically favorable. In cells, ΔS is increased by increasing the amount of H2O consumed, resulting in ΔG >0 and an increase in the reaction rate.
b. Because ΔG < 0, the hydrolysis of ATP is not thermodynamically favorable. In cells, enzymes act as catalysts that decrease ΔH for the reaction, resulting in ΔG >0 and an increase in the reaction rate.
c. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a small activation energy.
d. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a large activation energy.
Answers
Answer:
d. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a large activation energy.
Explanation:
Hello!
In this case, since negative Gibbs free energies of reaction stand for thermodynamically favored processes, we can immediately rule out choices a. and b.
Moreover, since the reaction is slow without the presence of a catalyst, which the context of biochemistry is an enzyme, we infer that correct choice is d. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a large activation energy because the higher the activation energy the slower the reaction according to the Arrhenius equation.
Best regards!
Convert Fahrenheit temperature
to Kelvin scales
Answers
Answer:
K = (F – 32)5/9 + 273.15
Explanation:
You basically convert Fahrenheit to Celcius and then to Kelvin
Here's the entire formula:
K = (x °F – 32)5/9 + 273.15
Need help fast help help help. Help
Answers
Answer:
fjnjfzgnf
Explanation:
Answer:
it blank !
Explanation:
What does it mean for heat to be transferred by thermal conduction?
Answers
Answer:
thermal energy
Explanation:
Thermal conduction is the diffusion of thermal energy (heat) within one material or between materials in contact. The higher temperature object has molecules with more kinetic energy; collisions between molecules distributions this kinetic energy until an object has the same thermal energy throughout.
Answer:
energy is transferred when one molecule collides with another.
Explanation:
aP33x
A compound X has the following percentage composition 66.7% carbon, 11.1% hydrogen and 22.2% oxygen .Calculate the empirical formula of X.The relative molecular mass of X is 72 calculate the molecular formula
Answers
Explanation:
c. h. o
66.7%. 11.1%. 22.2%
____. ____. ____
12. 1. 16
1.558. 11.1. 1.39. (divide by the smallest)
1. 8. 1
empirical formula=ch8o
How many grams of sodium (Na) are in 6.2 mol of Na?
Answers
mass = mol no. x molar mass
= 6.2 x 23
= 142.6 g
A student dissolves 10.2 g of sodium hydroxide (NaOH) in 250. g of water in a well-insulated open cup. He then observes the temperature of the water rise from 21.0 °C to 32.7 °C over the course of 3.7 minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction: NAOH(s) → Na" (aq) + OH (aq) You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to 3 significant digits. do Note for advanced students: Its possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction. O exothermic Is this reaction exothermic, endothermic, or neither? O endothermic O neither If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case. kJ Calculate the reaction enthalpy AH per mole of NaOH. mol
Answers
Answer:
A) The reaction is an exothermic reaction
B) 12.744 kJ
c) 49.976 KJ/mol . NaOH
Explanation:
A) The reaction is an exothermic reaction
B) calculate the amount of heat that was released or absorbed by the reaction in this case. kJ
Assuming : specific heat of solution = specific heat of water = 4.186 J/g°C
mass of solution = 10.2 + 250 = 260.2 g
determine The heat released in the reaction
= mass of solution * specific heat of solution * temperature change
= 260.2 * 4.186 * ( 32.7 - 21 )
= 12.744 kJ
C) Calculate the reaction enthalpy ΔH per mole of NaOH. mol
Reaction enthalpy = - heat released / ( 10.2 /40 )
= - 12.744 / ( 10.2/40 ) = - 49.976 KJ/mol . NaOH
One mole of hydrogen is equal to____
Answers
6.02 x 10^23 hydrogen molecules
(AKA Avogadro’s constant)
Write the equation for the acid dissociation, write the Ka expression, solve for Ht concentration, then do an ICE chart. Put the values into the Ka expression (the one you solved for Ht and find Ht, convert to pH and input that to 2 decimal place. Or use the Henderson-Hasselbalch equation:
pH = pka, + log ( Base/Acid)
Calculate the pH of a buffer solution consisting of 0.39 M HA (Ka = 8.8 x 10^-6) and 0.2 M NaA.
Answers
Answer:
The pH of the buffer is 4.77
Explanation:
Using Henderson-Hasselbalch equation we can solve the pH of the buffer:
pH = pKa + log [A⁻] / [HA]
Where pH is the pH of the buffer
pKa is -log Ka = 5.056
[A⁻] = [NaA] = 0.2M
[HA] = 0.39M
Replacing:
pH = 5.056+ log [0.2] / [0.39]
pH = 4.77
The pH of the buffer is 4.77
Question 9 a N20(9) + CO(9) - N2(9) + CO2(9) The rate of the reaction represented above increases significantly in the presence of Pd(s). Which of the following best explains this observation?
А Pd increases the activation energy of the reaction.
B Pd absorbs the heat produced in the reaction. C One of the reactants binds on the surface of Pd, which introduces an alternative reaction pathway with a lower activation energy.
D One of the products binds on the surface of Pd, which increases the reaction rate by decreasing the concentration of products in the mixture.
Answers
Answer:
Ans choise B
Explanation:
Increasing rates of reaction by catalysts always results because of decrease in activation energy occurs.
on analysis an ammonium salt of an alkanoic acid gave 60.5% C and 6.5% H if 0.309g of the salt yield 0.0313g of Nitrogen determine the empirical formula of the salt [ H = 1, C =12, N = 14, O= 16]
Answers
Answer: C7H9NO2
Explanation:
%N = 0.0313/0.309 x 100
= 10.1%
%0 = 100 — (60.5 + 6.5 + 10.1)
= 22.9
C; 60.5/12 H; 6.5/1 N; 10.1/14 O; 22.9/16
C; 5.04/0.72 H; 6.5/0.72 N; 0.72/0.72 O; 1.43/0.72
Empirical formula — C7H9NO2
what is the name of these 4 compound in isomers
Answers
Answer:
C9H19 C5H12 C6H17 C7H20
Explain why anhydrous aluminium chloride is fairly soluble in organic solvent while anhydrous magnesium chloride is insoluble
Answers
Answer:
The correct answer is - anhydrous aluminum chloride is covalent whereas anhydrous magnesium chloride is ionic.
Explanation:
Anhydrous aluminum chloride is a covalent compound and we know that covalent compounds have less or no polarity. Organic compounds or solvents are mostly non-polar in nature. And it is a thumb rule that like-dissolves-like.
Thus they dissolve covalent molecules like anhydrous aluminum chloride.
Anhydrous magnesium chloride is an ionic compound that tends to interact with a polar solvent but not in a non-polar solvent such as organic solvents.
Anhydrous aluminum chloride is fairly soluble in the organic solvent while anhydrous magnesium chloride is insoluble because anhydrous aluminum chloride is covalent whereas anhydrous magnesium chloride is ionic.
Why is AlCl3 soluble in organic solvent?AlCl3 quite simply accepts electrons from other atoms, in an try and get a full valence shell of eight electrons. It's why it normally behaves as a Lewis acid. In the response under, the Al atom accepts a lone pair of electrons from a Cl atom.
Why is AlCl3 soluble in water?AlCl3 is hygroscopic and has a great affinity for water. Therefore, aluminum chloride dissolves in water partially.
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