Answer:
7.40×10²² molecules.
Explanation:
From the question given above, the following data were obtained:
Volume of oxygen = 2.75 L
Number of molecules of oxygen =?
Next, we shall determine the number of mole of oxygen present. This can be obtained as follow:
22.4 L contains 1 mole of oxygen at STP.
Therefore, 2.75 L will contain = 2.75 / 22.4 = 0.123 mole of oxygen at STP.
Finally, we shall determine the number of molecules of oxygen present. This can be obtained as follow:
From Avogadro's hypothesis:
1 mole of oxygen = 6.02×10²³ molecules
Therefore,
0.123 mole of oxygen = 0.123 × 6.02×10²³
0.123 mole of oxygen = 7.40×10²² molecules.
Thus, the cylinder contains 7.40×10²² molecules of oxygen.
The extraction of iron from ore is represented by the chemical reaction equation.
Fe2O3 + 3CO → 2Fe + 3CO2
Calculate the mass of carbon (II) oxide required for the reduction of 40 kg of iron (III) oxide
Answer:
21 Kg of CO.
Explanation:
The balanced equation for the reaction is given below:
Fe₂O₃ + 3CO —> 2Fe + 3CO₂
Next, we shall determine the masses of Fe₂O₃ and CO that reacted from the balanced equation. This can be obtained as illustrated below:
Molar mass of Fe₂O₃ = (56×2) + (16×3)
= 112 + 48
= 160 g/mol
Mass of Fe₂O₃ from the balanced equation = 1 × 160 = 160 g
Molar mass of CO = 12 + 16 = 28 g/mol
Mass of CO from the balanced equation = 3 × 28 = 84 g
SUMMARY:
From the balanced equation above,
160 g Fe₂O₃ required 84 g of CO.
Finally, we shall determine the mass of of CO required for the reduction of 40 kg of Fe₂O₃. This can be obtained as follow:
From the balanced equation above,
160 g Fe₂O₃ required 84 g of CO.
Therefore, 40 Kg of Fe₂O₃ will require = (40 kg × 84 g) / 160 g = 21 Kg of CO.
Thus, 21 Kg of CO is required for the reaction.
Question 2 (1 point)
(02.01 LC)
Which scientist proposed the model of an atom as a solid sphere? (1 point)
John Dalton
Niels Bohr
Ernest Rutherford
William Crookes
Answer:
John Dalton
Explanation:
Both John Dalton and Democritus thought that the atom was an indivisible sphere until J.J. Thompson came out with the plum pudding model. Hope I helped!
what is the mass of 1.25 L of ammonia gas at STP
Answer:
mass 1.25 Liters NH₃(gas) = 0.949 grams (3 sig-figs)
Explanation:
At STP (Standard Temperature-Pressure conditions => 0°C(=273K) and 1atm pressure, 1 mole any gas will occupy 22.4 Liters.
So, given 1.25 Liters ammonia gas at STP, convert to moles then multiply by formula wt. (17g/mole gives mass of NH₃.
moles NH₃(gas) = 1.25L NH₃(gas)/22.4L NH₄(gas)· NH₃(gas)mole⁻¹ = 0.0558 mole NH₃(gas).
Converting to grams NH₃(gas) = 0.0558 mole NH₃(gas) x 17 g·mol⁻¹ = 0.949 grams NH₃(gas).
What is the mass of 0.063x10^-4 moles of aluminum sulphate ?
Answer:
The mass of 0.063*10⁻⁴ moles of aluminum sulphate is 2.15*10⁻³ grams.
Explanation:
Aluminum sulfate Al₂(SO₄)₃ has a molar mass of 342.15 g/mol.
Molar mass is the amount of mass that a substance contains in one mole of a substance, which can be an element or a compound.
So in this case you can apply the following rule of three: if 342.15 grams are present in 1 mole of aluminum sulfate, how much mass is present in 0.063*10⁻⁴ moles of the compound?
[tex]mass of aluminum sulphate=\frac{0.063*10^{-4}moles*342.15 grams }{1 mole}[/tex]
mass of aluminum sulphate= 2.15*10⁻³ grams
The mass of 0.063*10⁻⁴ moles of aluminum sulphate is 2.15*10⁻³ grams.
A certain protein transports a sodium ion from the inside of the cell membrane to the outside using active transport. Which of the following must be true? A. There is no change in concentration before or after transport. B. The transport process did not use chemical energy. C. After transport, the concentration of protein in the cell decreases. D. After transport, the concentration of sodium is lower inside the cell.
help please guys i need it
Answer:
Amplitude
Explanation:
Hope I helped :)
After you set up your apparatus for the second part of the experiment, your group begins to add the textbooks on top of the plunger. It appears that the plunger continues to drop with every added book and does not return to its original place after the books are removed. What possible sources of error could be given for this experimental outcome? Be specific and give at least two reasons.
The possible sources of error that could be given for this experimental outcome is the change in the density of the air.
What is an experiment?An experiment simply means the procedure that is carried out in order to refute a particular hypothesis. It should be noted that experiments are important to provide insights into the cause and effect of a particular situation.
In this situation, with every added book, the volume of that air column will reduce. It is just important that the temperature should remain constant when the gas compression is taking place.
Another source of error is the assumption of moles that was assumed was constant during the experiment. In this scenario, it's possible that some gas could have escaped while the compression was taking place.
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Which postmortem parameter is fixed by 8 hours?
1)cloudiness of the eyes
2)rigor mortis
3)livor mortis
4)putrefaction
1) Calculate the percent composition of each element in ammonia (NH).
Answer:
[tex]\% N=82.2\% \\\\\% H=17.8\%[/tex]
Explanation:
Hello there!
In this case, since ammonia is NH₃, we can see nitrogen weights 14.01 g/mol and hydrogen 3.03 g/mol as there is one only nitrogen atom and three hydrogen atoms; thus, the total mass is 17.04 g/mol. In such a way, the percent composition of each element turns out to be:
[tex]\% N=\frac{14.01}{17.04}*100\%=82.2\% \\\\\% H=\frac{3.03}{17.04}*100\%=17.8\%[/tex]
Best regards!
What is the atomic mass of element XX if 3.6 moles of the substance has a mass of 192 grams?
Answer:
53.3g/mol
Explanation
Moles=mass/molar mass
Molar mass= mass/moles
Molar mass= 192/3.6
= 53.3
Can u please help me name which one it is
Answer:
I think it is C
Explanation:
A gas takes
up a volume of 17 L, has a
pressure of 2.3 atm, and a temperature
of 299 K. If I raise the temperature to
350 K and lower the pressure to 1140
mmHg, what is the new volume?
Answer:
V₂ = 25.065 L
Explanation:
Given data:
Initial volume = 15L
Initial pressure = 1500 mmHg (1500/760 = 1.97 atm)
Initial temperature = 299 K
Final temperature = 350 K
Final volume = ?
Final pressure = 1050 mmHg (1050/760 = 1.38 atm)
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 1.97 atm × 15 L × 350 K / 299 K × 1.38 atm
V₂ = 10342.5 atm .L. K / 412.62 K.atm
V₂ = 25.065 L
Liquids B and C are partially miscible at 25 oC. When one starts with 1 mol of C at 25 oC and isothermally adds B a little at a time, a two-phase system first appears when a bit more than 0.125 mol of B has been added; continuing to add B, one finds the two-phase system becomes a one-phase system when a total of 3 mol of B has been added. For a system consisting of 2.5 mol of B and 2 mol of C at 25 oC, find the number of moles of B and of C present in each phase.
Answer:
[tex]0.8\overline 3[/tex] moles of A and 2.5 moles of B in the one-phase system
[tex]1.1 \overline 6[/tex] moles of A and [tex]0.1458 \overline 3[/tex] moles of B in the two-phase system
[tex]0.3541 \overline 6[/tex] moles of B remains in the system
Explanation:
The given parameters are;
The extent of miscibility of liquid B and C = Partially miscible
The number of moles of liquid B added to 1 mole of liquid A that forms a two-phase system = 0.125 mol of liquid B
The number of moles of liquid B added to 1 mole of liquid A that forms a one -phase system = 3 moles of liquid B
Whereby the system consist of 2.5 mol of B and 2 mol of C at 25°C, we have;
The 1 mole of A mixes with 3 moles of B to form a single phase solution
Therefore;
2.5 moles of B will mix with (1/3)×2.5 moles of A = 5/6 moles of A
The remaining number of moles of A in the system = 2 - 5/6 = 7/6 moles of A
Similarly, we have;
At least, 0.125 mole of B combines with 1 mole of A to form a two-phase system
7/6 moles of A will combine with 7/6 × 0.125 = 7/48 moles of B to form a two-phase system
The number of moles of B left = 0.5 - 7/48 = 17/48 = 0.3541[tex]\overline 6[/tex] moles of A
Therefore, we have;
5/6 moles of A and 2.5 moles of B in the one-phase system
7/6 moles of A and 7/48 moles of B in the two-phase system
17/48 moles of B remaining in the system
Plasma can be found naturally in
O water and ice.
O stars and lightning.
O wood and metal.
O comets and asteroids.
Answer:
stars and lightning. this is the answer ok
Balance the chemical equation
C2H6+O2 = CO2 +H2O
(b) The student collects the H2(g) produced by the reaction and measures its volume over water at 298 K after carefully
equalizing the water levels inside and outside the gas-collection tube, as shown in the diagram below. The volume is
measured to be 45.6 mL. The atmospheric pressure in the lab is measured as 765 torr, and the equilibrium vapor pressure
of water at 298 K is 24 torr,
45
46
Gas
Water
Calculate the following.
() The number of moles of h2 produced in the reaction
Answer:
The pressure of H₂(g) = 741 torr
Explanation:
Given that:
The atmospheric pressure measured in the lab = 765 torr
The vapor pressure of water = 24 torr
By applying Dalton's Law of Partial Pressure :
Making The Pressure inside the tube due to the H₂(g) the subject of the formula :
we have:
= (765 -24) torr
= 741 torr
According to ideal gas law and Dalton's law of partial pressure, 0.0136 moles of hydrogen are produced in the reaction.
What is ideal gas law?The ideal gas law is a equation which is applicable in a hypothetical state of an ideal gas.It is a combination of Boyle's law, Charle's law,Avogadro's law and Gay-Lussac's law . It is given as, PV=nRT where R= gas constant whose value is 8.314.The law has several limitations.It is applicable to ideal gases which have hypothetical existence.Law was proposed by Benoit Paul Emile Clapeyron.
In the given problem, according to Dalton's law of partial pressure, pressure =765-24=741 torr
Substituting the given values in the ideal gas equation, n=PV/RT
n=741×45.6×10[tex]^-3[/tex]/8.314×298=0.0136 moles.
Thus 0.0136 moles of hydrogen are produced in the reaction.
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Fill in the blanks. 3NH3
Answer:
3, 9, 3
Explanation:
The coefficient of 3 tells us that there are three molecules (the chemical unit of NH3). Each molecule of ammonia (NH3) is made up of 1 atom of nitrogen bonded to 3 atoms of hydrogen.
Since there are three molecules, we have three times the amount of atoms there are in one molecule.
3 x 1 = 3 nitrogen
3 x 3 = 9 hydrogen
Which set of coefficients will correctly balance the following skeleton equation?
Fe + Cl2 →FeCl3
Answer:
2Fe + 3Cl2 → 2FeCl3
Explanation:
The subscript represents the number of ____________ in a chemical equation.
Cool air can hold less water vapor than warm air. Apply this fact to explain why clouds and precipitation form on the windward side of the mountain.
The pressure is directly proportional to temperature (when the pressure decrease the temperature decrease too). Because the air parcel expands so the molecules will not interact with each other as much.
The energy of the particles does not change but the fact that the particles are more spaced out means the parcel is cooler.
so now, the warmer a parcel of air the more water vapor it can hold. so, if a parcel of air cools it's ability to hold water vapor drops and if it drops to a low enough point that is when the water vapor will condense and turn back into liquid water. This is how clouds and precipitation form on the the windward side of the mountain.
Clouds and precipitation form on the windward side of the mountain due to change in temperature and pressure.
What is the relation between pressure and temperature?
Temperature of any substance is directly proportional to the pressure of that substance.
If the temperature of the wind increases so that winds get warmer and at the same time pressure of gas also increases, due to which particles will go far from each other. After this warm air rises up and cools down will condenses to form clouds, after this precipitate will falls on the windward side of the mountain.
Hence due to temperature and pressure precipitate will form on the windward side of the mountain.
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Pls someone help rn!! Pls pls
Answer:
A. Mass = 61kg, weight on moon = 97.8N
Explanation:
To calculate the weight (force) from Mass of a body, the following formula is used:
W = mg
Where;
W = weight (Newtons)
m = mass (kg)
g = acceleration due to gravity (9.8m/s²)
According to this question, a scale shows that I weigh 600N on Earth, the mass on Earth can be calculated thus:
Using W = mg
m = W/g
m = 600/9.8
m = 61.2
m = 61kg
However, this mass on Earth will weigh differently on the Moon because gravity in the moon is 1.6 N/kg. The weight of the 61kg on the Moon is:
W(moon) = mass × gravity
W = 61 × 1.6
W = 97.6 N
Therefore, Mass = 61kg, weight on moon = 97.8N
Sulfur
how many electron shells in 4th shell?
Answer:
16 electrons in a sulfur atom. Looking at the picture, you can see there are two electrons in shell one, eight in shell two, and six in shell three.
Explanation:
Astronauts go to live on the International Space Station for a period of ________ month(s). A one B three C six D nine
Answer:
The answer is C. six months
Explanation:
I hope this helps you bestie:))
I need help with like 35 questions anyone willing to help please let me know I have discord
UnknownGoddxss#2795
Please I only have like 5 hours to complete this
Answer and Explanation:
The molar mass of a substance is all of the weights from the elements combined.
So, we have the elements
CU, S, and [tex]O_{4}[/tex]
CU has a mass is 65
S mass is 32
O has a mass of 16, but there's 4 atoms of O, so we do 16 times 4, which is 64.
Now we add.
65 + 32 + 64 is 161.
So, the answer is 160, or answer choice A.
#teamtrees #PAW (Plant And Water)
Elizabeth REALLY didn’t study, and she also wrote the formula for dicarbon tetrafluoride as “C2F5”. Describe why her answer is incorrect.
Answer:
correct formula: C2F4
Explanation:
tetra means 4. There are 2 C and 4 F in dicarbon tetrafluoride.
Who among, Amit and Saaketh, is correct? Explain.
Answer:
What is their question answers exactly? I won't be able to explain who is correct.
Explanation:
Answer:
Not a lot to draw from this question if im going to be honest
Explanation
How many grams equal 4.3 x 1024 atoms of oxygen (02)?
Answer: 248.66g
Explanation:
4.3e24 / 6.23e23 = 6.9 mols O2
6.9(18.02*2)=248.66
chemical properties of elements
Answer:
Atomic number. The atomic number indicates the number of protons within the core of an atom. ...
Atomic mass. The name indicates the mass of an atom, expressed in atomic mass units (amu). ...
Electronegativity according to Pauling. let me know if you need more ;)
what is derived from sheep and goats that is used in break fluid
A bones and horns
B Fats and Fattys acids
C Manure
D Wool and Lanolin
the answer is A I took the test
Which of the following is a characteristic of both the Earth and the Moon?
Fossils and fossil
fuels under the
surface
Rocky surface
covered with
landforms
Flowing water in
Oceans and rivers
Atmosphere
containing oxygen
Answer:
rocky surface covered with landforms
Explanation: