the bigger the object the more weight of the planet or gravity is acted upon if
The weight of the purified caffeine is often much lower than the weight of the crude caffeine. Explain why the percent recovery is frequently low?
Answer:
see explanation
Explanation:
When caffeine is purified, the impurities are removed, these impurities are responsible for the greater mass of pure caffeine compared to the mass of the pure sample.
The percent recovery of caffeine is frequently low because some caffeine is often left behind in the solvent during the process of recrystallization.
Secondly, since caffeine is a sublime substance, some caffeine may be lost o sublimation leading to a low percent recovery of pure caffeine.
Consider the diagram below.
What does C represent?
A) enthalpy of reaction
B) activation energy
C) activated complex
D) energy of the reactants
Answer:
A) enthalpy of reaction
Explanation:
The region C signifies the enthalpy of reaction.
This diagram is the energy profile of an endothermic reaction. In such reaction, heat is absorbed from the surrounding. At the end of the reaction, the heat of product is lesser than that of the reactants.
Enthalpy changes are heat changes accompanying a physical and chemical change. An enthalpy is the difference between the sum of the heat contents of products and sum of the heat contents of reactants.it is indeed A) enthalpy of reaction
Atoms of two different elements must have different
electrical charges.
numbers of neutrons.
atomic numbers.
energy levels.
GIVE EXPLANATION!!!!
Answer:
c atomic numbers
Explanation:
hope this helps
Answer:
atomic numbers
Explanation:
In order for two atoms to be different, they have to have a different number of protons. Protons are represented by the atomic number. Thus, atoms of two DIFFERENT elements must have different atomic numbers.
I took the test and got 100%
Hope this helps!
A petroleum refinery is producing the four products shown in the table. The table also shows the state of matter at room temperature of each of the substances. All of these compounds are molecular compounds consisting of only hydrogen and carbon. Which of the following products is likely to have the highest molecular weight? A. Natural gas B. Gasoline C. Jet fuel D. Paraffin wax
Answer:D
Explanation: in molecular solids, one factor that determines the strength of intermolecular forces is the mass of the molecules. Since all of these compounds only contain hydrogen and carbon we don’t have to worry about their polarities as they are all the same. Inter molecular forces tend to be stronger when the molecular weight is greater since paraffin wax is the only solid at room temperature it has the highest melting point
Answer: Your Answer Is D. Paraffin wax
Explanation:Hope This Helps!
If3.91 potassium metal is
allowed to react with oxygen,
O2, the reaction yields 7.11g of k2o.
How much oxygen was reacted?
Calculate the wavelength of light (in nm) of the spectral line of Hydrogen where an electron falls from the 6th Bohr orbit to the 3rd Bohr orbit.
a) 540 nm
b) 2000 nm
c) 1090 nm
d) 1050 nm
Answer:
The wavelength of light (in nm) of the spectral line of Hydrogen where an electron falls from the 6th Bohr orbit to the 3rd Bohr orbit is 1090nm
Explanation:
We know that , the wavelength of the light is calculated by Rydberg's formula-
[tex]\frac{1}{\pi} =R^2(\frac{1}{n^2_1} -\frac{1}{n^2_2})[/tex] [tex][n_2>n_1][/tex]
Here , R = Rydberg's constant [tex](1.097\times 10^7 m^-^1)[/tex]
Z = atomic number (for hydrogen , Z= 1)
[tex]n_2 =6 , n_1=3[/tex]
[tex]\pi =[/tex] wavelength of light
Now , putting the values in the Rydberg's formula ,
[tex]\frac{1}{\pi} =1.097\times10^7m^-^1(\frac{1}{3^2} -\frac{1}{6^2} )[/tex]
=[tex]1.097\times 10^7m^-^1 (\frac{4-1}{36} )[/tex]
=[tex]1.097\times 10^7m^-^1(\frac{3}{36} )[/tex]
=[tex]1.097\times 10^7m^-^1(\frac{1}{12} )[/tex]
[tex]\frac{1}{\pi}[/tex] = [tex]0.0914167\times 10^7m^-^1[/tex]
[tex]\pi=\frac{1}{0.0914167\times10^7m^-^1}[/tex]
[tex]\pi=10.9389\times10^-^7\\\pi=1093.89\times10^-^9m[/tex]
=1090nm
Hence , the wavelength of the light is 1090nm,, that is option D is correct.
What is the value of E0 for the spontaneous reaction resulting from a suitable combination of these half reactions?
Standard Potentials E0
Fe2+ --> Fe3+ + e- -0.77 V
2Hg --> Hg2+ + 2e- -0.79 V
a. +0.02 V.
b. +0.36 V.
c. -1.56 V.
d. -0.02 V.
e. +1.56 V.
Answer:
+0.02 V
Explanation:
For the reaction to be spontaneous, iron must be the cathode and Mercury the anode
Given that the standard cell potential is obtained from;
E°=E° cathode - E° anode
Since;
E° cathode = -0.77V
E° anode = 0.79 V
E°cell = -0.77 -(-0.79)
E°cell = +0.02 V
if you wanted to measure in irregular object's volume, which device would you use?
Answer:
a beaker
Explanation:
SOMEONE PLZ HELP!!!!
Answer:
4.22mL
Explanation:
V=m/d
v= 18.45g/4.37g/mL
2. Determine the possible traits of the calves of : Da red (RR) bull is mated with a red (RR) cow 1 a red * (RR) bullis mated with a white (WW) Cow 2 Da roan * (RW) is mated with a red(RR)Cow 3 3. Illustrate your answers using a Punnett square. 4. Write your answers on the paper.
Someone plz hello me ASAP it would be appreciated on question 7 btw
Answer:
Kinetic Energy is the correct Answer.
Explanation:
At the highest point on the roller coaster (assuming it has no velocity), the object has a maximum quantity of gravitational potential energy. As the object begins moving down to the bottom, its gravitational potential energy begins to decrease and the Kinetic Energy starts to increase.
Which is one way that minerals crystallize from materials dissolved in water?
from the air
from solutions that evaporate
from hot water solutions when water boils
from the soil
Answer:
the second answer its science behind it
Answer:
b
Explanation:
plz help answer both will mark brainest
3. Does matter increase in
mass when mixed with
another substance?
a Yes
b. No
Answer:
b. No
Explanation:
The question above is related to "The Law of Conservation of Mass." This law states that mass is neither created nor can it be destroyed. Even if a particular matter will be mixed with another substance or it undergoes chemical reaction, the mass of the matter will remain the same. Even with a change in phase, the mass of the matter will remain the same.
Which phase change results in an increase in entropy?
1.
12(9) - 12(s)
2.
CH2(g) - CH40
3.
Br2(1) - Br2(g)
4.
H20(1) - H20(s)
The phase change that results in an increase in entropy is the change; Br2(1) - Br2(g)
What is entropy?The term entropy refers to the degree of disorderliness in a system. We have to note that gases have a higher entropy than liquids and liquids have a higher entropy than the solids.
As such, the phase change that results in an increase in entropy is the change; Br2(1) - Br2(g)
Learn more about entropy:https://brainly.com/question/12786977
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During a solar eclipse, which of the following is true?
HELP
Answer:
The moon blocks the Sun's light from hitting the surface of the earth
Explanation:
pentane or 2,2,3- trimethylhexane has the higher boiling point. why?
Answer:
2,2,3- trimethylhexane because it has more carbon atoms than pentane.
Explanation:
Hello.
In this case, since the physical properties of organic compounds are intensified as the number of carbon atoms start increasing on it, the larger the amount of carbon atom, the higher the boiling point since more energy is required to allow the liquid-phase molecules to transcend to the vapor-phase.
In such a way, since pentane has five carbon atoms and 2,2,3- trimethylhexane has nine carbon atoms, 2,2,3- trimethylhexane has the highest boiling point.
Best regards.
Which energy source would be the best source of energy for rescue workers?
List the sources from worst to best.
Combustion Engine
Solar Cell
Nuclear Power Plant
Hydroelectric Power Plant
Human Powered Generator
Wind Turbine
Fuel Burning Power Plant
Answer:
Solar Cell
Explanation:
Claim 1: The sun (solar cells) is the best energy source for the rescue team.
what might happen to variables in a science experiment that would lead to unusable results?
Answer:
ejeb094
Explanation:
nnb3neneie9eei rje
Please help! I'm confused on a few of these, 100 points!
Which of the following particles combine to form molecules?
Compounds
Protons
Electrons
Atoms
Answer: i think its protons and electrons but it also might just be atoms because protons and electrons make atoms when there are also neutrons
Explanation:
Which condition produces an anion?
A. more neutrons than electrons
B. more protons than electrons
C. more electrons than neutrons
D. more electrons than protons
Which of the following objects would have the smallest wavelength at the same velocity?
Baseball
Electron
Planet Earth
Proton
Answer: Planet Earth
Explanation: Wavelength (λ) is equal to h/mυ , where m = the mass of your object and υ = the frequency. Since Earth has the largest mass of the options, we can conclude that Earth will have the smallest wavelengths out of the rest.
The wavelength of matter-waves is given by the De Broglie formula. The larger the object, the smaller the observed wavelength hence the object having the smallest wavelength is Planet Earth.
De Broglie established the relationship between the momentum and the observed wavelength of an object. This proposition came to be known as wave-particle duality.
The wavelength of matter waves is given by;
λ = h/mv
Where;
λ = wavelength
m = mass of object
v = velocity of the object
If all the objects have the same velocity, the magnitude of the wavelength now depends on the mass of the object.
The object having the largest mass among the options is planet earth (5.972 × 10^24 kg).
Hence planet earth has the smallest wavelength among the options listed.
Learn more; https://brainly.com/question/7143261
PLS PLS PLS PLS PLS PLS PLS help ASAP!!!!! Scientists call all of the compounds that contain carbon and are found in living things Organic because ________.
WILL DO BRAINLIEST!
Two elements in the same period have the same number of _____ _____ in their electron clouds.
Answer:
outer electrons
Explanation:
Answer:
Energy levels
Explanation:
PRACTICE PROBLEM Two compounds, A and B, have the same molecular formula, C6H8. Both A and B react with two molar equivalents of hydrogen in the presence of platinum to yield cyclohexane. Compound A shows three signals in its broadband decoupled NMR spectrum. Compound B shows only two NMR signals. Compound A shows an absorption maximum at 256 nm, whereas B shows no absorption maximum at wavelengths longer than 200 nm. What are the structures of A and B
Answer:
See explanation
Explanation:
One basic thing that we must keep in mind is that A and B are both dienes.
The NMR spectrum and absorption maxima of A and B indicates that A may be a conjugated diene while B may be an isolated diene.
Remember that conjugated dienes shift the absorption maxima to longer wavelengths due to π - π* transition.
The two structures attached may suffice for compounds A and B
The density of wind-packed snow is estimated to be 0.35 g/cm^3. A flat roof that is 35 by 43 feet has 28 inches of snow on it. How many pounds of snow are on the roof?
Answer:
There are 76728.2 pounds of snow on the roof
Explanation:
To determine how many pounds of snow are on the roof,
First we will determine the mass of the snow in grams.
From the question,
Density of snow = 0.35 g/cm³
From
Density = Mass / Volume
To determine the mass, we will first find the volume.
From the question, a flat roof that is 35 by 43 feet has 28 inches of snow on it, that is, the height of the snow on the roof is 28 inches.
Area of the roof = 35 ft × 43 ft = 1505 ft²
Volume of the snow = Area of the roof × Height of the snow
Height of the snow = 28 inches
12 inches = 1 foot
∴ 28 inches = 28/12 feet = 2.3333 ft
Hence,
Volume of the snow = 1505 ft² × 2.3333 ft = 3511.62 ft³
Volume of the snow = 3511.62 ft³
This is the volume of the snow in cubic feet
Now, we will convert cubic feet (ft³) to cubic centimeter (cm³)
1 ft = 30.48 cm
and 1 ft³ = 30.48³ cm³ = 28316.84659 cm³.
If 1 ft³ = 28316.84659 cm³
∴ 3511.62 ft³ will be 3511.62 × 28316.84659 cm³ = 99438004.83 cm³
Hence, Volume of snow = 99438004.83 cm³
Now, we can determine mass of snow in grams
From
Density = Mass / Volume
Mass = Density × Volume
Mass = 0.35 g/cm³ × 99438004.83 cm³
Mass = 34803301.69 g
Now, we will convert the mass from grams to pounds
1 pound = 453.592 grams
If 453.592 grams = 1 pound
Then, 34803301.69 g will be 34803301.69 / 453.592 pounds = 76728.2 pounds
Hence, there are 76728.2 pounds of snow on the roof.
What concentration of NO−3NO3− results when 897 mL897 mL of 0.497 M NaNO30.497 M NaNO3 is mixed with 813 mL813 mL of 0.341 M Ca(NO3)2?
Answer:
Explanation:
NaNO₃ = Na⁺ + NO₃⁻¹
.497 M .497 M
moles of NO₃⁻¹ = .897 x .497 = .4458 moles
Ca( NO₃)₂ = Ca + 2 NO₃⁻¹
.341 M 2 x .341 M = .682 M
moles of NO₃⁻¹ = .813 x .682 = .5544 moles
Total moles = .4458 moles + .5544 moles
= 1.0002 moles
volume of solution = 897 + 813 = 1710 mL
= 1.710 L
concentration of nitrate ion = 1.0002 / 1.710 M
= .585 M
The first energy level which has p orbitals to fill is ___
1
2
3
4
Answer:
2
Explanation:
The Aufbau sequence of increasing energy levels is 1s,2s,2p,3s,3p,4s,3d and so on....
Hope this helps! :D
For a water in equilibrium with the atmosphere, a pH of 2.0, and a total soluble iron concentration of 1 mg/L, calculate the concentrations of Fe2+(aq) and Fe3+(aq).
Answer:
Fe^2+(aq) = 4.51 × 10^-11 M
Fe3+(aq) = 1.79 × 10^5 M.
Explanation:
So, the first thing to do is to to write out the chemical reaction showing the ionic reaction of the chemical species present in the chemical reaction;
4Fe^2+ (aq) + O2(g) + 4H^+ <---------------------------> 4Fe^3+(aq) + 2H2O(l).
The next thing to do is to determine or calculate for G° and the equilibrium constant,kc. Thus, the value of G° = 4(-4.6) + 2(-237.18) - {4(-78.87)} = -177.28 kJ/mol.
Therefore, the equilibrium constant = e^-∆G°/RT = 1.19 × 10^31.
Therefore the value for Fe^2+ and Fe^3+ can be determine as;
NB=> Recall that [Fe^3+]/[Fe^2+] = kc [(Po2) (H^+)^4]^1/4.
Also, 1/ 55850 = 1.79 × 10^-5 M.
[Fe^2+] + [Fe^3+] = 1.79 × 10^-5. -------(1).
Therefore, [Fe^3+]/[Fe^2+] = kc [(Po2) (H^+)^4]^1/4. = [Fe^3+]/[Fe^2+] = [ 1.19 × 10^31 × 0.2095 × (10^2)^2] ^1/4 = 3.97 × 10^5.
Therefore, [Fe^3+]/[Fe^2+] = 3.97 × 10^5.
[Fe^3+] = 3.97 × 10^5[Fe^2+].
Hence, using the equation (1) above we can determine the value of the species.
[Fe^2+] + [Fe^3+] = 1.79 × 10^-5
[Fe^2+] + [Fe^2+] = 1.79 × 10^-5.
[Fe^2+] + 3.97 × 10^5[Fe^2+] = 1.79 × 10^-5.
[Fe^2+] = 4.51 × 10^-11 M.
Therefore, we will have [Fe^3+]/[Fe^2+] = 3.97 × 10^5.
Thus, [Fe^3+] = [Fe^2+] × 3.97 × 10^5. = 1.79 × 10^5 M.