Answer:
The "Bohr Model", works only for hydrogen because it considers only the "interactions" between one electron and the nucleus.
Explanation:
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what is the density of a block of wood measuring 9cmx2cmx6cm with the mass of 5.4g
Answer:
0.05 g/cm^3.
Explanation:
The volume of the block = 9*2*6 = 108 cm^3.
Density = mass/volume
= 5.4 / 108
= 0.05 g/cm^3.
Determine the value of the equilibrium constant (report your answer to three significant figures) for the following reaction if an equilibrium mixture contains 0.010 mol of solid PbBr2, and is 0.0100 M in Pb2+ ions and 0.0250 M in Br1- ions. Use the notation 4.31e-5 to indicate a number such as 4.31 x 10-5.
Answer:
6.25e-6 is the value of the equilibrium constant
Explanation:
we have this equation
[tex]PbBr(s) ----- Pb^{2+}(aq) + 2Br(aq)[/tex]
When at a state of equilibrium,
we have the concentration of Pb^2+ to be 0.01
we have the concentration of Br^- to be 0.025
the equilibrium constant concentration of both pure solids and liquid s are said to be equal to 1
[PbBR2] = 1
such tht
Keq = [Pb^2+] x [Br-]^2
we already know the values of these from the above.
0.01x0.025^2
= 0.01 x 0.000625
= 0.00000625
= 6.25 x 10^-6
= 6.25e^-6
How many grams of Cl are in 31.2g CF2Cl2
Answer:
Mass = 42.6 g
Explanation:
Given data:
Mass of CF₂Cl₂ = 31.2 g
Mass of Cl₂ = ?
Solution:
Number of moles of CF₂Cl₂ = mass/molar mass
Number of moles = 31.2 g/121 gmol
Number of moles = 0.3 mol
1 mole of CF₂Cl₂ contain 2 moles of Cl atom.
0.3 mol × 2 = 0.6 mol
Mass of Cl₂:
Mass = number of moles × molar mass
Mass = 0.6 mol × 71 g/mol
Mass = 42.6 g
Use the periodic table to identify the chemical symbol or name for each element below.
zirconium:
zr
rhenium:
re
: As
: K
tin:
yttrium:
: Yb
Answer:
zirconium is Zr
rhenium is Re
As is arsenic
K is potassium
tin is Sn
yttrium is Y
ytterbium is Yb
Explanation:
With the help of the periodic table, the identification of the chemical symbol or name for each element is represented as follows:
Zirconium: Zr. Rhenium: Re. Arsenic: As.Potassium: K.Tin: Sn. Yttrium: Y. Ytterbium: Yb. What are the chemical elements?Chemical elements may be defined as any type of substance that cannot be further decomposed into simpler substances through the utilization of other ordinary chemical processes or external factors. These elements possess specific physical as well as chemical properties distinctly.
In the modern periodic table, each element is arranged on the basis of its increasing atomic number. Each element possesses its unique symbol, atomic mass, and physical properties like boiling points, melting points, density, etc.
Therefore, with the help of the periodic table, the identification of the chemical symbol or name for each element is well represented above.
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Choose all the right answers.
Choose the two places where continental glaciers can be seen.
Iceland
Norway
Antarctica
Greenland
Answer:
the real answer is Iceland, Norway, Antarctica.
Explanation:
It is not Green land proof Glaciers are not an unusual sight in Greenland due to the gigantic ice sheet that covers most of the country. However, there are only a few places where the glaciers occur immediately adjacent to a town, and therefore can be appreciated on an excursion.
proof for Antarctica These large-scale features of glacial erosion can be seen in Antarctica where rock protrudes above the surface of the ice sheet There are many glaciers in the Antarctic. ... The lists include outlet glaciers, valley glaciers, cirque glaciers, tidewater glaciers and ice streams. Ice streams are a type of glacier and many of them have "glacier" in their name, e.g. Pine Island Glacier
proof for Norway are the largest glaciers on mainland Norway. ... In total, Norway has around 1,600 glaciers - 900 of these are in North Norway, but 60% of the total glacier area is south of Trøndelag. 1% of mainland Norway is covered by glaciers.
proof for Iceland Glaciers in Iceland are among the best natural wonders in the world. In fact, the country's glaciers are so great that you can see them from space! With 11% of the total land area covered by ice caps, Iceland is a glacier paradise. Here are the five most amazing glaciers that you must see when visiting Iceland!
What is the volume of a substance that has a mass of 59 g and a density of 1.98 g/mL?
(show all work)
Answer:
29.8
Explanation:
The formula for volume is mass/ density, so 59/1.98. 29.8 is the answer.
What is the molarity of a solution that contains 7.0 moles of solute in 9.0 liters of solution?
Answer:
The answer is 0.78 mol/dm³Explanation:
In order to calculate the molarity of the solution we use the formula
[tex]c = \frac{n}{v} \\ [/tex]
where
c is the molarity
n is the number of moles
v is the volume in dm³
From the question
n = 7 mol
v = 9 L = 9 dm³
We have
[tex]c = \frac{7}{9} \\ = 0.77777777...[/tex]
We have the final answer as
0.78 mol/dm³Hope this helps you
True or False: The exact location of an electron can be measured thanks to
modern science.
Answer:
false you can not get a exact location of electrons from just modern science
PLEASE HELP, WILL MARK BRAINLIEST!
The best way to find the volume of an empty bottle is to...
a) weigh the bottle and record the mass, then add the water and subtract its mass from that of the empty bottle
b) fill the bottle with water and place it on a balance
c) fill the bottle with water, and then empty the water into a graduated cylinder.
Answer:
C
Explanation:
True or False: Particles that are moving faster have a higher temperature
Answer:
true
Explanation:
I'm not sure why cause I dont know how to explain but it's TRUE
Answer:
True
Explanation:
The particles moving faster in a substance the hotter it gets.
which one of these best defines climate
please help i will mark brainlest answer if correct asap
Answer:
Long term condition of the atmosphere
Explanation:
I think this is right.
I hope this helps! (✿◕‿◕✿)
An ideal gaseous reaction (which is a hypothetical gaseous reaction that conforms to the laws governing gas behavior) occurs at a constant pressure of 35.0 atm and releases 74.6 kJ of heat. Before the reaction, the volume of the system was 8.20 L . After the reaction, the volume of the system was 2.80 L . Calculate the total internal energy change, ΔE, in kilojoules.
Answer:
ΔU = −55.45 kJ
Explanation:
From first law of thermodynamics in chemistry, we have;
ΔU = Q + W
where;
ΔU is change in internal energy
Q is the net heat transfer
W is the net work done
We are given;
Q = 74.6 kJ
But Q will be negative since heat is released
Thus;
ΔU = -74.6 kJ + W
We are given;
Constant pressure; P = 35 atm = 35 × 101325 = 3546375 N/m²
Volume before reaction; Vi = 8.2 L = 0.0082 m³
Volume after reaction; V_f = 2.8 L = 0.0028 m³
Now,
W = -P(V_f - V_i)
W = - 3546375(0.0028 - 0.0082)
W = 19.15 KJ
Thus;
ΔU = Q + W
ΔU = -74.6 kJ + 19.15 KJ =
ΔU = −55.45 kJ
Calcium reacts with sulfur forming calcium sulfide. What is the theoretical yield (g) of CaS(s) that could be prepared from 7.19 g of Ca(s) and 2.67 g of sulfur(s)? Enter your answer with two decimal places. Do not type units with your answer.
Answer:
The theoretical yield of CaS is 6.01 g.
Explanation:
The balanced reaction is given as:
[tex]Ca+S\rightarrow CaS[/tex]
The molar mass of Ca and S is 40.08 and 32.065 g/mol respectively.
Number of moles = [tex]\frac{Mass}{Molar Mass}[/tex]
So, 7.19 g of Ca contains [tex](\frac{7.19}{40.08})[/tex] mol of Ca or 0.179 mol of Ca
Also, 2.67 g of S contains [tex](\frac{2.67}{32.065})[/tex] mol of S or 0.0833 mol of S
According to the balanced equation:
1 mol of Ca produces 1 mol of CaS
So, 0.179 mol of Ca produces 0.179 mol of CaS
According to the balanced equation:
1 mol of S produces 1 mol of CaS
So, 0.0833 mol of S produces 0.0833 mol of CaS
As the least number of mol of CaS (product) is produced from S , therefore, S is the limiting reactant.
So, thoretically, 0.0833 mol of CaS is produced.
The molar mass of CaS is 72.143 g/mol.
So, the mass of 0.0833 mol of CaS is [tex](0.0833\times 72.143)[/tex] g or 6.01 g
Hence, the theoretical yield of CaS is 6.01 g.
a 108ml sampl of gas has a mass of 77.96mg at a pressure of 1140mmhg and temperature of 183°c .what is the molar mass of the gas ?
Answer:
146.85 g/mol
Explanation:
PV=nRT
n=mass/molar mass
covert from mmhg to atm = 0.184 atm
convert from ml to L= 0.108 L
convert from degree C to K= 456.15 K
convert from mg to g= 0.07796g
then rearrange the formula:
n=PV/RT
=(0.184)(0.108)/(0.08206)(456.15)
n= 5.308*10^(-4)
rearrange the n formula interms of molar mass:
Molar mass= mass/n
=0.07796/(5.308*10^-4)
molar mass= 146.85g/mol
Answer:
Molar mass = 20 g/mol
Explanation:
Given data:
Volume of gas = 108 mL
Mass of gas = 77.96 mg (77.96/1000 = 0.08 g)
Pressure of gas = 1140 mmHg
Temperature of gas = 183°C
Molar mass of gas = ?
Solution:
First of all we will calculate the number of moles of gas.
PV = nRT
R = general gas constant = 0.0821 atm.L/ mol.K
Now we will convert the units and then we will put the values in formula.
Volume of gas = 108 mL× 1 L/1000 mL= 0.108 L
Pressure of gas = 1140 mmHg× 1 atm / 760 mmHg = 1.5 atm
Temperature of gas = 183+273 = 456 K
PV = nRT
1.5 atm ×0.108 L = n × 0.0821 atm.L/ mol.K ×456 K
0.162 atm.L = n ×37.44 atm.L/ mol
n = 0.162 atm.L/37.44 atm.L/ mol
n = 0.004 mol
Molar mass of gas:
Number of moles = mass/molar mass
0.004 mol = 0.08 g / molar mass
Molar mass = 0.08 g /0.004 mol
Molar mass = 20 g/mol
. A nail is hammered into a piece of wood. *
Answer:
and now you have a nail in your wood :)
A teaspoon of salt, NaCl has a mass of about
5.0 g. How many formula units are in a
teaspoon of salt?
Answer: The answer is 5.15x10^22
Explanation:
The formula unit present in a teaspoon of salt [tex]NaCl[/tex] having a mass of about 5.0 g is [tex]5.15 \times10^{22}[/tex] formula units.
Molar mass, also known as molecular weight, is the mass of one mole of a substance. It is calculated by summing up the atomic masses of all the atoms in a molecule. The unit of molar mass is grams per mole (g/mol).
Now, to determine the number of formula units in a teaspoon of salt (NaCl), we need to use Avogadro's number and the molar mass of NaCl.
Avogadro's number [tex](N_a)[/tex] is approximately. [tex]6.022 \times10^{23}[/tex] formula units per mole.
The molar mass of [tex]NaCl[/tex] is the sum of the atomic masses of sodium (Na) and chlorine ([tex]Cl[/tex]), which are approximately 22.99 g/mol and 35.45 g/mol, respectively.
To calculate the number of formula units in 5.0 g of [tex]NaCl[/tex], we can follow these steps:
Now, calculate the number of moles of [tex]NaCl[/tex] using its molar mass:
Moles = Mass / Molar mass
Moles = [tex]5.0 g[/tex] / [tex](22.99 g/mol + 35.45 g/mol)[/tex]
Calculate the number of formula units using Avogadro's number:
Formula units = [tex]Moles \times Avogadro's number[/tex]
Let's perform the calculation:
Molar mass of [tex]NaCl[/tex]= [tex]22.99 g/mol + 35.45 g/mol = 58.44 g/mol[/tex]
Moles of [tex]NaCl[/tex] = [tex]5.0 g[/tex] / [tex]58.44 g/mol[/tex] ≈ [tex]0.0856 mol[/tex]
Formula units = [tex]0.0856 mol \times (6.022 \times 10^{23})[/tex] formula units/mol ≈ [tex]5.15 \times10^{22}[/tex]formula units.
Therefore, there are approximately [tex]5.15 \times10^{22}[/tex] formula units in a teaspoon of salt ([tex]NaCl[/tex]) having mass [tex]5.0 g[/tex].
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What do you need to measure the amount of energy in food
Answer:
u measure how much power it has
Explanation:
for example u can power a light bulb woth it if u can it was 100eg energy
What is the pressure if the height of a column of mercury is 0.20 m and the density of mercury is 13,600 kg/m3? (remember, gravity is 9.81 m/s2)
Answer:
[tex]p=26683.2Pa[/tex]
Explanation:
Hello,
In this case, since the pressure is computed via:
[tex]p=h*\rho*g[/tex]
Whereas h is the 0.520-m height, [tex]\rho[/tex] is the 13600-kg/m³ density and the g the 9.81-m/s² gravity. Thus, the pressure in Pa is:
[tex]p=0.20m*13,600 \frac{kg}{m^3} *9.81\frac{m}{s^2} \\\\p=26683.2\frac{kg*\frac{m}{s^2} }{m^2} =26683.2\frac{N}{m^2}\\ \\p=26683.2Pa[/tex]
Best regards.
Answer each of the following questions with increases, decreases, or does not change.
a) If the intermolecular forces in a liquid increase, the normal boiling point of the liquid increases .
b) If the intermolecular forces in a liquid increase, the vapor pressure of the liquid does not change .
c) If the surface area of a liquid increases, the vapor pressure increases .
d) If the temperature of a liquid decreases, the equilibrium vapor pressure increases .
Drag and drop your selection from the following list to complete the answer:
does not change decreases increases
Answer:
1) Increases
2) decreases
3) increases
4) decreases
Explanation:
When the intermolecular forces in a liquid increases, the greater vapour pressure of the liquid decreases accordingly.
Since the vapour pressure is proportional to temperature, as temperature increases, the vapour pressure increases alongside.
As intermolecular forces increases, the boiling point increases accordingly since more energy is required to break intermolecular bonds.
Lastly, the greater the surface area, tell greater the vapour pressure since more liquid surface area is now available.
What occurs after cytokinesis is completed at the end of meiosis I?
O Four haploid cells are formed.
O Two diploid cells are formed.
OTwo haploid cells are formed.
O Four diploid cells are formed.
Answer. After cytokinesis is completed at end of meiosis - I two haploid cells are formed.on:
Answer:
C. TWO HAPLOID CELLS ARE FORMED
Explanation:
I TOOK THE EDGUNITY TEST AND I GOT IT CORRECT
The equilibrium constant _____________. For an ___________ reaction, heat is a reactant. An increase in temperature and heat favors the ____________ reaction and the value of K c _____________.
Answer:
The equilibrium constant change. For an endothermic reaction, heat is a reactant. An increase in temperature and heat favors the forward reaction and the value of Kc increases.
Explanation:
Hello.
In this case, regarding reactions in equilibrium in which heat is a reactant as those exemplified by:
[tex]Heat+Reactants \rightleftharpoons Products[/tex]
We infer that the heat of reaction is positive since the reactants have more energy in their ground state than the products making them endothermic. Moreover, since the Le' Chatelier's principle states that increasing the reaction temperature in endothermic reactions, the forward reaction (towards products) is favored because endothermic reactions absorb heat in the form temperature raise, the required statement is:
The equilibrium constant change. For an endothermic reaction, heat is a reactant. An increase in temperature and heat favors the forward reaction and the value of Kc increases.
Regards.
Answer:
The equilibrium constant increases. For an endothermic reaction heat is a reactant. An increase in temperature and heat favours the forward reaction and the value of KC increases.
Explanation:
What can the chemical formula tell us about a compound?
Answer:
A chemical formula tells us the number of atoms of each element that is in a compound. It contains the symbols of the atoms for the elements present in the compound as well as how many there are for each element in the form of subscripts.
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God bless :)
Scientists are experimenting with pure samples of isotope X which is radioactive. The sample has a mass of 20. Grams. The half-life was measured to be 232 seconds. There is a second sample that weighs 80 grams. What is the half-life of the second sample
Answer:
Explanation:
Half life of radioactive materials do not depend upon the mass of the material . It only depends upon the nature of radioactive materials . The half life of 20 g is 232 seconds . That means 20 gram will be reduced to 10 gram in 232 seconds .
Half life of 80 gram is also 232 seconds . So , 80 gram will be reduced to 40 gram in 232 second .
why are copper pipes used in place of old lead pipes for plumbing systems?
A proton is a very tiny particle inside an atom. The mass of a proton is
estimated to be 0.00000000000000000000000167 g. What is the mass of a
proton in scientific notation?
Answer:
1.67 ×10^-24g
Explanation:
counting from the first digit after the point till I got to the first non zero digit
what are the benefits of using supercritical fluids in EGS
Answer:
See detailed explanation.
Explanation:
Hello.
In this case, it is firstly necessary to cite that EGS accounts enhanced geothermal systems which are man-made reservoirs, placed where lots of hot rock is present but there is lack natural permeability, which requires a fluid to be injected into the subsurface to re-open it and therefore creating permeability.
Typically, water has been used for this purpose, but due to the current issue on saving water alternative methods such as supercritical fluids has been being implemented because they have better dynamic properties such as lower viscosities and therefore larger flow velocities, supercritical CO2 is easy and cheap to get as low temperatures are required to turn it in supercritical condition.
Best regards.!
convert 575.1 mmHg to atm
Answer:
= .7567105263
Explanation:
1 atm = 760 mmHg
575.1 mmHg (1 atm/760mmHg) = .7567105263 atm
A sample of an unknown gas weighs 0.419 grams and produced 5.00L of gas at 1.00atm (unknown gas only) and 298.15K, what is the molar mass (g/mole) of this unknown gas
Answer:
molar mass of unknown gas = 1.987 g/mol
Explanation:
First, the number of moles of the unknown gas is found
Using the ideal gas equation: PV = nRT
P = 1.00 atm, V = 5.00 L, T = 298.15 K, R = 0.082 L.atm.mol⁻¹K⁻¹
n = PV/RT
n = (1.00 atm * 5.00 L)/(298.15 K *0.082 L.atm.mol⁻¹K⁻¹)
n = 0.2109 moles
Molar mass = mass/ number of moles
molar mass = 0.419 g/ 0.2109 mols
molar mass of unknown gas = 1.987 g/mol
The molar mass of unknown gas by using ideal gas equation = 1.987 g/mol.
Ideal gas equationThis equation gives the relation between pressure, volume, temperature as given below:
[tex]PV = nRT[/tex]
P = 1.00 atm, V = 5.00 L, T = 298.15 K, R = 0.082 L.atm.mol⁻¹K⁻¹
Substitute the above values in the above equation as follows:
n = (1.00 atm * 5.00 L)/(298.15 K *0.082 L.atm.mol⁻¹K⁻¹)
n = 0.2109 moles
Formula for molar mass[tex]Molar mass = mass/ number of moles[/tex]
Calculate molar mass by using the above equation,
molar mass = 0.419 g/ 0.2109 moles
The molar mass of unknown gas = 1.987 g/mol
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What element in the second period has the largest atomic radius?
a
neon
b
lithium
c
carbon
d
potassium
Answer:
b) Lithium
Explanation:
Sketch the titration curve for the titration of a generic weak base B with a strong acid. The titration reaction is
B+H+⇌BH+
On the curve indicate the points that correspond to the following:
a) the equivalence point.
b) the region with maximum buffering) the point where pH = pKbd) the region where pH depends only on [B]e) the region where pH depends only on [BH+]f) the region where pH depends only on the amount of excess strong acid
Answer:
Kindly check the attached picture.
Explanation:
Titration is one of the useful concept or practical in chemistry which is used in the determination of the concentration of a particular chemical specie. Without mincing words, let us dive straight into the solution to the question;
(a) Determining the equivalence point using the graph.
=> The equivalence point is the point at which there has been been "enough" addition of the acid to the base to give us the congugate acid. In the diagram showing the curve, it is the point labelled (a).
(b)The next thing is to determine the region with maximum buffering.
=> The position with the maximum buffering ranges from the point labelled (b) in the graph and it is the point when the acid and the base has been added. But the point with the maximum buffering is labeled as point (c).
(c). Determination of the point where pH = pKb.
=> The Point in which the pH = pKb is the point a
(d). The region where pH depends only on [B].
=> The starting point in the point in which the pH is dependent on the concentration of the base, [B].
(e). The region where pH depends only on [BH+].
=> This is the same point with point labelled as (a). Thus, point (a) and (e) are the same.
(f). The region where pH depends only on the amount of excess strong acid is the point labelled as (f) which is known as the post equivalence point.