(a) Gel permeation chromatography (GPC) would be used to determine the number average molar mass M for poly(ethylene glycol). A suitable solvent for the measurements is tetrahydrofuran (THF). The method separates the polymer molecules based on their size, and the number average molar mass is determined by calculating the average molecular weight of the sample. Possible errors in the determination include changes in the polymer structure due to the solvent or temperature, and the presence of impurities in the sample.
(b) Vapor pressure osmometry (VPO) would be used to determine the number average molar mass M for polyacrylonitrile. A suitable solvent for the measurements is dimethylacetamide (DMAc). The method determines the molecular weight of a polymer by measuring the vapor pressure difference between a solution of the polymer in solvent and the pure solvent. Possible errors in the determination include the presence of impurities in the sample and changes in the polymer structure due to the solvent or temperature.
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convex mirror is used as a rear view mirror in vehicles why give reasons
Answer: We prefer a convex mirror as a rear-view mirror in vehicles because it gives a wider field of view, which allows the driver to see most of the traffic behind him. Convex mirrors always form a virtual, erect, and diminished image of the objects placed in front of it.
please help with this question!!
Answer:
A.9.0 A
Explanation:
This is multiplication then add.
3*2+3=9.0
And that is how we get the answer.
PLEASE HURRY
What does the investigation of Earth's layers reveal about the history of the
formation of our planet?
Answer:
there's a center of the earth..and there is every later of it..just like in a movie...it is true
Answer:
The layers of rock at Earth ’s surface contain evidence of the evolutionary processes undergone by these components of the terrestrial environment during the times at which each layer was formed. By studying this rock record from the very beginning, it is thus possible to trace their development and the resultant changes through time.
plzzz answer with explnation!!!
the value of acceleration due to gravity (g) will be maximum at:
a) 1/2 of the radius of earth
b) 1/4 of the radius of earth
c) 1/8 of the radius of earth
Answer:
a. 1/2 of the radius of earth
Explanation:
g= GM/r²thus g is inversely proportional to radius
5. Identify the reactants in this chemical equation:
2H3PO4 → HAP20, +H2O
Answer:
H=Hydrogen, PO4=Phosphate
Explanation:
Reactions are on the left side of arrow and products are on the right side of arrow.
A 80.0 kg person on rollerblades pushes against a 700. Kg box on wheels with a force of 50.0 N and they roll away from each other. The person accelerates to the left and the box accelerates to the right.
Answer:
person a₁ = -0.625 m / s², box a₂ = 0.0714 m / s²
Explanation:
In this exercise we have a problem of action and reaction forces, the force with which the person (action) pushes the box is of the same magnitude as the force with which the box (reaction) pushes the person, but in the opposite direction.
We work that body separately
Person
-F = m₁ a₁
a₁ = -F / m₁
a₁ = -50.0 / 80.0
a₁ = -0.625 m / s²
the negative sign means that the person moves away from the box
Box
F = m₂ a₂
a₂ = F / m₂
a₂ = 50.0 / 700
a₂ = 0.0714 m / s²
A soccer player strikes a soccer ball with a force of 550 N. If the player and the ball remain in contact for 0.03 s. What impulse was delivered to the ball by the player?
do you weigh yourself regularly?what the things you do to adjust if your weight starts to slip upward or downward?
Answer:
start a healthy diet. But starting a healthy diet doesn't mean only eating greens, you should minimize the amount of regular food you take and eat a balanced diet.
Weight is the measure of the mass of the body. Mass is the amount of matter a body contains.
Personally, I do weigh myself regularly in order to determine the action to take if the weight either slips upward or downwards.If the weight slips upward, what I do is to reduce the amount of calorie intake and also exercise. Reduction in calorie intake and regular exercise can drastically reduce the weight of a body considerably.If otherwise, I ensure I regularly consume a balanced diet and energy-giving foods.Learn more here: https://brainly.com/question/9693067
list 10 uses of metals
Answer:
Shiny metals such as copper, silver, and gold are often used for decorative arts, jewelry, and coins.
Strong metals such as iron and metal alloys such as stainless steel are used to build structures, ships, and vehicles including cars, trains, and trucks.
Some metals have specific qualities that dictate their use. For example, copper is a good choice for wiring because it is particularly good at conducting electricity. Tungsten is used for the filaments of light bulbs because it glows white-hot without melting.
Nonmetals are plentiful and useful. These are among the most commonly used:
Oxygen, a gas, is absolutely essential to human life. Not only do we breathe it and use it for medical purposes, but we also use it as an important element in combustion.
Sulfur is valued for its medical properties and as an important ingredient in many chemical solutions. Sulfuric acid is an important tool for industry, used in batteries and manufacturing.
Chlorine is a powerful disinfectant. It is used to purify water for drinking and fill swimming pools.
Explanation:
The carbon atom with 12 protons and 12 electrons has a charge of:
a. 1 C
b. +12 C
c. -1 C
d. 0 C
e. -12 C
Answer:
Isotopes are the elements having the same atomic number i.e same number of protons which in turn is equal to same number of electrons. Number of protons and electrons are equal as the atom is electrically neutral. So, the only option is A.
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(V) What are the objectives of the space mission?
Explanation:
I hope this helps, I got this from another person
is an increase in speed in a certain time .
a. Acceleration
b. ActionReaction Pairs
c. Force
d. Inertia
It's Acceleration
We can calculate the average speed by finding the total distance traveled divided by the elapsed time: Average speed=–s=Total distanceElapsed time. Average speed = s – = Total distance Elapsed time.
What would the acceleration of a car be from a stoplight if it started at 0 m/s and reached a
speed of 100 m/s in 7.8 seconds?
Answer:
The acceleration of a car would be: [tex]a=12.8[/tex] m/s²
Explanation:
Given
Initial velocity = [tex]v_1=0[/tex] m/s
Final velocity = [tex]v_f=100[/tex] m/s
Time elapsed = [tex]t = 7.8[/tex] s
To determine
We need to determine the acceleration of a car.
We know that acceleration is basically the rate of change in velocity over time.
Thus,
We can determine the acceleration using the formula
[tex]\:\:\:a=\:\frac{v_f-v_i}{t}[/tex]
where
[tex]a[/tex] is the acceleration[tex]v_1[/tex] is the initial velocity[tex]v_f[/tex] is the final velocity[tex]t[/tex] is time elapsednow substituting the values [tex]v_1=0[/tex], [tex]v_f=100[/tex], and [tex]t = 7.8[/tex] in the formula
[tex]\:\:\:a=\:\frac{v_f-v_i}{t}[/tex]
[tex]a=\:\frac{100-0}{7.8}[/tex]
[tex]a=\frac{100}{7.8}[/tex]
[tex]a=12.8[/tex] m/s²
Therefore, the acceleration of a car would be: [tex]a=12.8[/tex] m/s²
1. We expect a conductor to be a constant voltage throughout. The conductive surface (silver marks) is mostly a constant voltage, but sometimes you may observe a millivolts-ish difference between different points on it. What does this mean about said conductive surface?
Answer:
Answer is explained in the explanation section below.
Explanation:
If the conductor has developed the potential difference. It simply means it is charged.
A conductor can be charged in different scenarios, let's discuss some of it and try to deduce the appropriate meaning for this question.
A conductor can be charged due to ions or
A conductor can be charged if it come across any current carrying conductor, so as to gain induced emf.
So, In both of these case, both can be very reasons for its potential difference.
Anyone who answer will get brainlest
Answer:
D
Explanation:
work = Force x distance
work = 2000 x 2 = 4000
power = work÷ time
4000/.8 = 5000W
Answer:
The answer is D 5000w
Explanation:
work = Force x distance
work = 2000 x 2 = 4000
power = work÷ time
4000/.8 = 5000W
Pls answer quick will mark brainlest and 5 stars
Answer:A
Explanation:
It’s bigger I am not sure
Answer:
For the first question, the answer is
B. Kettle
what is ionisation?
Answer: Ionisation is the process of an atom gets a negative or a positive charge by gaining or losing electrons. The result is an ion.
Explanation: Thats why
After Sophia eats her body breaks down the food to use as an engery source when she runs this is an example of which type of engery conversion
Answer:
cannibalism
Explanation:
because she is eating her body!
4. Find the valency of atoms of chlorine, sulphur and magnesium.
Answer:
1. Chlorine = 7 valence electrons.
2. Sulphur = 6 valence electrons.
3. Magnesium = 2 valence electrons.
Explanation:
In Chemistry, valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.
1. Chlorine = it is an element found in group (7) of the periodic table known as halogens and as such it has 7 electrons in its outermost shell. Therefore, Chlorine has seven (7) valence electrons.
Sulphur = this element is found in group (6) of the periodic table and as such it has 6 electrons in its outermost shell. Therefore, Sulphur has six (6) valence electrons.
Magnesium = this element is found in group (2) of the periodic table and as such it has 2 electrons in its outermost shell. Therefore, Magnesium has two (2) valence electrons.
if anyone has course hero could you send me the Gizmo Fan Cart Physics?
Answer:
I might be able to help, but I also might not. I need to check if I can get you the answer.
Explanation:
pls help i’ll give brainliest if you give a correct answer!!
Why can’t the high-quality energy released from a lump of burning coal be recycled?
Answer:
when energy changes from one form to another, it always goes from a more useful to a less useful form. This means that people can't recycle or reuse high quality energy to perform useful work.
When energy changes from one form to another, it always transitions from a more helpful to a less useful one. Because of this, people are unable to reuse or recycle high-quality energy to complete crucial tasks.
What is the term of burning coal?Coal is most frequently and significantly used in combustion, where heat is produced to create steam, which in turn powers the turbines that generate electricity. All living things, including humans, are composed of carbon. However, as coal burns, its oxygen reacts with airborne oxygen to generate carbon dioxide. Although dioxide (CO2) is an odourless, colourless gas, it is one of numerous gases found in the atmosphere that can retain the heat from the planet.
Why is burning coal a problem?It's a major issue for climate change since it produces more carbon dioxide when burned than oil or gas. In addition to producing microscopic soot particles and hazardous substances like arsenic and mercury, coal also contributes to air pollution.
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Bronco the skydiver, whose mass is 80 kg experiences 200 N of air resistance and gravity pulls on him with 800 N What is the acceleration of his fall?
Bronco the skydiver, whose mass is 80 kg experiences 200 N of air resistance and gravity pulls on him with 800 N. The acceleration of his fall 7.5 m/sec².
What is force?A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
To find the acceleration,
F = mg
F = 80.(10)
F = 800 N
air resistance = 200 N
Net force = F - air resistance
= 800 - 200
= 600 N
600 = mass . acceleration
600 = 80 . acceleration
acceleration = 7.5 m/sec²
Bronco the skydiver, whose mass is 80 kg experiences 200 N of air resistance and gravity pulls on him with 800 N. The acceleration of his fall 7.5 m/sec².
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Jenny is studying a compound that has two oxygen atoms and one nitrogen atom. Which statement describes the subscripts she will use to write the chemical formula? She will use one 2 as a subscript. She will use one 2 and one 1 as subscripts. She will use one 3 as a subscript. She will use two 2s and one 1 as subscripts.
Answer:
She will use one 2 as a subscript.
Explanation:
Nitrogen is a chemical element with the symbol "N" and has an atomic number of 7. Thus, it is found in group (5) of the periodic table and as such it has 5 electrons in its outermost shell. Therefore, nitrogen has two (5) valence electrons.
On the other hand, oxygen has an atomic number of 8 and with the symbol "O."
When nitrogen and oxygen react chemically, they produce a compound known as nitrogen dioxide [tex] NO_{2} [/tex]
In this scenario, Jenny is studying a compound that has two oxygen atoms and one nitrogen atom. Therefore, the statement which describes the subscripts she will use to write the chemical formula is, she will use one 2 as a subscript.
[tex] N + O_{2} ------> NO_{2} [/tex]
Where: 2 represents the subscript of oxygen.
Answer:
A- she will use 2 as a subscript
Explanation: because im doing the test rn and i got it right on edg2021
if a town was 90 miles away and you travel at 45 mph how long would it take to get there
Answer:
t = 2 hours
Explanation:
Given that,
Distance of the town, d = 90 miles
Speed, v = 45 mph
We need to find the time to get there. The speed of an object is given by :
[tex]v=\dfrac{d}{t}[/tex]
Where
t is time
[tex]t=\dfrac{d}{v}\\\\t=\dfrac{90}{45}\\\\t=2\ h[/tex]
So, the required time is 2 hours.
Which situation involves kinetic energy being transformed into sound energy?
Answer:
c
Explanation:
this is because you move ( kinetic energy) your hands and clap the other person's hand, you will definitely hear sound right.
Answer:
c
Explanation:
When they move their hands together their energy transforms to sound energy.
White light is an _____________ mixture of all the colors.
a) observable b) unequal c) equal
Answer:
unequal
Explanation:
White light is a combination of all colors in the color spectrum.
Answer: C) equal
If you use a glass prism, you can split white light into a rainbow which shows all of the colors along a spectrum. Each little color slice is the same width. In other words, something like green doesn't dominate the spectrum and take up a wider portion compared to other colors.
an atom has 5 protons, 6 neutrons, and 5 electrons. what is the atomic mass?
Answer:
the atomic mass is 11
Explanation:
the atomic mass is basically how many protons and neutrons there are so for this all you have to do is some simple math:
5 + 6 = 11
and boom, ur atomic mass is equal to 11!
Your are on a boat on a lake with no current. The lake is full of sharks that will eat you if you put your hands too close to the water, and your paddle has been eaten by those sharks. However, you do have a big bucket of grapefruit in the boat. How will you get to shore? Your answer must reference Newton's third law.
Answer:
throw the lakes to make a current maybe?
Explanation:
Mr. Rosa sees a random flying object headed towards his student’s face. He sprints at 13 m/s in 2 seconds. How fast did Mr. Rosa accelerate to save his student?
What is your known?
What is your unknown?
Plug it in.
What is your answer?
Answer:
13m/s
Explanation:
actually the answer is already given the thing which is not given is the distance which is 26 m which Mr Rosa walked it in 2 secs
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