How many times as fast does helium (He) effuse compared to oxygen?
Answer:
The rate of effusion of helium is always about twice that of oxygen.
Explanation:
Recall Graham's law of effusion:
[tex]\displaystyle \frac{r_1}{r_2} = \sqrt{\frac{\mathcal{M}_2}{\mathcal{M}_1}}[/tex]
Where r are the rates of effusion and M are the respective molecular weights.
Let r₁ be the effusion rate of helium and r₂ be the effusion rate of oxygen. Hence, M₁ = 8.00 g/mol and M₂ = 32.00 g/mol.
Substitute:
[tex]\displaystyle \begin{aligned}\frac{r_1}{r_2} & = \sqrt{\frac{(32.00\text{ g/mol})}{(8.00\text{ g/mol})}} \\ \\ & = \sqrt{4.00} \\ \\ & = 2.00 \end{aligned}[/tex]
Solving for r₁ yields:
[tex]\displaystyle \begin{aligned} \frac{r_1}{r_2} & = 2.00\\ \\ r_1 & = 2.00r_2\end{aligned}[/tex]
Hence, the rate of effusion of helium is always about twice that of oxygen. This is expected, as helium is smaller than oxygen.
8. Choose the compound that is metallic.
P4010
NaCI
FE
Your answer is FE, or iron!
Describe How did the sun form?
The Sun formed about 4.6 billion years ago in a giant, spinning cloud of gas and dust called the solar nebula. As the nebula collapsed under its own gravity, it spun faster and flattened into a disk.
Answer:
in space billons of year ago dust particles together to create solar nebula also the sun made with helium and hydrogen the sun will run out of energyhope it's helpful thanks
Direct ethanol fuel cells (DEFCs) have shown some promise as a viable option for providing "green" energy to small electrical devices. Calculate E° for the reaction that takes place in DEFCs:
C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)
Use the following values.
∆G°H2O(l) = -237 kJ/mol
∆G°O2(g) = 0 kJ/mol
∆G°CO2(g) = -394 kJ/mol
∆G°C2H5OH(l) = -175 kJ/mol.
Eo = ? V
The emf of the cell from the reactions and the change in free energy is 2.8 V.
What is the Eocell?The Eocell refer to the emf of the cell under standard conditions. In this case, it can be obtained from the free energy of the values of the reactants and products.
Now, given; C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)
ΔG°rxn = [2(-394) + 2( -237)] - [( -175 ) + 0 ]
= [(-788) + (-474)] + 175
= -1087 kJ/mol
Also;
ΔG° = -nFEocell
Eocell = ΔG° /-nF
Eocell = -1087 * 10^3/-(4 * 96500)
Eocell =-1087 * 10^3/386000
= 2.8 V
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Is Fe^+2 the same ion as Fe^2+?
Yes, it doesn't matter if you put the number first or the sign first therefore... +2 = 2+
No, Fe^+2 is a cation and Fe^2+ is an anion
Answer:
It doesn't matter because either or it's still a cation because its positive
Which statement best describes the relationship between ocean CO2 and pH?
Question 3 options:
When CO2 increases, pH increases and acidity decreases.
When CO2 increases, pH decreases and acidity increases.
When CO2 increases, pH decreases and acidity decreases.
There is no relationship between CO2 and pH
Answer:
The answer is When CO2 increases, pH decreases and acidity increases.
Explanation:
Excess carbon dioxide (CO2) in the atmosphere gets absorbed at the ocean surface of the ocean. This excess CO2 results in more hydrogen ions, which increases the acidity of the ocean.
Which element is most similar to nitrogen: Carbon or Phosphorus?
What is the total energy required to break all the bonds in 1 mol hexane, c6h14
The enthalpy of formation or the total energy required to break all the bonds in 1 mol hexane and has a value of -198.67 kJ.
What is the energy of bond breaking?The energy of bond breaking is the energy required to break all the bonds in 1 mole of a substance.
This energy is also the energy required to form the bonds known as enthalpy of formation of that substance.
Therefore, the total energy required to break all the bonds in 1 mol hexane is known as it enthalpy of formation and has a value of -198.67 kJ.
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Hydrochloric acid is usually purchased in a concentrated form that is 37.0% HCl by mass and has a density of 1.20 g/mL. How much concentrated solution would it take to prepare 3.00 L of 0.480 M HCl upon dilution with water?
The required volume of concentrated stock solution of hydrochloric acid is 102.71 mL.
What is the relation between the volume & density?Volume of any solution will be calculated by using the density as:
Volume = Mass/Density
Given that percent mass of HCl is 37%, so mass of the HCl = 37g
So that mass of solution = 100g
And density of solution = 1.2 g/mL
Volume of solution = 100/1.2 = 83.33 mL = 0.08333 L
Moles of HCl will be calculated as:
n = W/M, where
W = given mass = 37g
M = molar mass = 36.4g/mol
n = 37/36.4 = 1.014mol
Then the molarity of the stock solution will be calculated as:
M = n/V
M = 1.014 / 0.0833 = 12.17M
Now the required volume of stock solution will be calculated by using the following equation as:
M₁V₁ = M₂V₂, where
M₁ & V₁ is the molarity and volume of stock solution and M₂ & V₂ is the molarity and volume of dilute solution. On putting values in the above solution we get
12.17 × V₁ = 0.5 × 2500
12.17 × V₁ = 1250
V₁ = 102.71 mL
Hence required volume of stock solution is 102.71 mL.
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Which type of cell is shown in the following image?
Answer:
A prokaryotic cell is shown in the image
Explanation:
Prokaryotic cells are the most basic types. Since they are basic, they don't have a nucleus. All eukaryotic cells have it but prokaryotic cells don't have it. A nucleus contains organelles such as a mitochondria which the diagram doesn't show as well. Thus a prokaryotic cell is shown in the image.
An atom becomes an ion when there are
Question options:
unequal numbers of protons and electrons
equal number of protons, neutrons, and electrons
a different number of neutrons than protons
equal numbers of protons and electrons
Answer:
Unequal number of protons and electrons
Explanation:
When an atom loses or gains electrons, this affects its charge, thus creating it an ion (a charged atom)!
Pls help !
What happens to the speed of a tsunami wave as it approaches the shore?
It increases and then decreases.
It increases.
It remains at a constant speed.
It decreases.
Which term represents when a tsunami wave slows down as it reaches shore?
surfing
waving
sinking
shoaling
Answer: It decreases.
Explanation:
Another word for, The spinning of a planet on its axis
Answer:
A rotation
Explanation:
Calculate the volume in liters of 50.0 grams of NO2 at STP.
According to the mole concept, the number of moles in 50 g of NO₂ is 1.086 as molar mass of NO₂ is 46 g and as per STP conditions volume is 24.32 L.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Initially the number of moles is calculated as, 50/46=1.086 moles . As 1 mole occupies 22.4 L at STP conditions,1.086 moles occupy 1.086×22.4=24.32 L.
Hence, the volume in liters of 50 g of NO₂ at STP is 24.32 L.
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Energy and Chemical Reactions: Mastery Test 4 Select the correct answer. Which factor is defined as the average kinetic energy of a substance? A. the mass of the substance B. the volume of the substance C. the pressure of the substance D. the temperature of the substance
Answer:
D. Temp
Explanation:
Temperature is a mesure of the KE of the molecules/atoms of the substance
1. A weather balloon with a volume of 2000L at a pressure of 96.3 kPa rises and the pressure
decreases to 60.8kPa. Assuming there is no change in the temperature or the amount of gas,
calculate the weather balloon's final volume.
Answer:
3167 .8 liters
Explanation:
P1 V1 = P2 V2
96.3 * 2000 = 60.8 * V2 solve for V2 =3167.8 l
The value of AH° for the reaction below is -1107 kJ:
2Ba(s) + O₂(g) → 2BaO(s)
How many kJ of heat are released when 5.75 g of Ba(s) reacts completely with oxygen to form BaO(s)?
Select one:
O a. 96.3
O b. 26.3
O c. 46.4
O d. 23.2
Oe. 193
Answer:
C
Explanation:
We can use heat stoichiometry. Thus, convert from grams of Ba to moles of Ba; and use the ΔH value to calculate the amount of heat released. Hence:
[tex]\displaystyle 5.75\text{ g Ba}\cdot \frac{1\text{ mol Ba}}{137.33\text{ g Ba}} \cdot \frac{1\text{ mol}_{rxn}}{2\text{ mol Ba}} \cdot \frac{-1107\text{ kJ}}{1\text{ mol}_{rxn}} =-46.4 \text{ kJ}[/tex]
Therefore, about 46.4 kJ of heat was released.
In conclusion, our answer is C.
A molecule has two bonded atoms around the central atom. The central atom does not have any lone pairs. What is the geometry of the molecule?
Bent
Linear
Trigonal planar
Tetrahedral
Answer:
I think Tetrahedral
Explanation: HaHa I D K
Answer:
Linear
Explanation:
Because it has zero lone pairs and only two atoms.
is KNO a strong acid?
Answer:
First of all, it's KNO₃ not KNO.
Second, KNO₃ is neither an acid nor it is a base, infact, it is a salt and therefore it's neutral.
hope that helps...
How did you do? Rate your work on a scale of 1 to 5, with 5 as the highest score. Then write a brief evaluation of your work below. Note what you learned and what challenged you.
Blood samples are important for toxicology tests in crime forensics. However, there are other biological samples that are commonly used for post-mortem toxicology. Research three such biological specimens. Describe how they are collected and their significance.
u did a five because u are awsome.
Answer:
I would rate myself a 5 because I completed all the work with no issues.
Explanation:
The normal boiling point of a liquid is 282 °C. At what temperature (in °C) would the vapor pressure be 0.500 atm? (∆Hvap = 28.5 kJ/mol)
For a normal boiling point of a liquid is 282 °C, the temperature is mathematically given as
T2=181.55°C\
What temperature (in °C) would the vapor pressure be 0.500 atm?Generally, the equation for the gas is mathematically given as
ln(p1/p2)=dHvap/R(1/T2-1/T1)
Therefore
ln(1/0.26)=23500/8.214(1/T2-1/555)
T2=181.55^C
In conclusion
T2=181.55°C
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AgC2H3O2 + K2CrO4 = Ag2CrO4 + KC2H3O2 How many moles of silver chromate, Ag2CrO4 are produced in this reaction
Taking into account the reaction stoichiometry, 1 mole of silver chromate Ag₂CrO₄ are produced in this reaction.
Reaction stoichiometryIn first place, the balanced reaction is:
2 AgC₂H₃O₂ + K₂CrO₄ → Ag₂CrO₄ + 2 KC₂H₃O₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
AgC₂H₃O₂: 2 moles K₂CrO₄: 1 mole Ag₂CrO₄: 1 moleKC₂H₃O₂: 2 molesMoles of Ag₂CrO₄ formedBy reaction stoichiometry 2 moles of AgC₂H₃O₂ form 1 mole of Ag₂CrO₄.
In other words, according to this balanced chemical equation, 1 mole of silver chromate Ag₂CrO₄ are produced in this reaction.
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What is the total number of electrons in the correct Lewis dot formula of the phosphate ion?
30
26
36
34
32
How many moles of water are needed in order to produce 21.8 g of
calcium hydroxide?
CaC2 + 2H₂O -------> C₂H₂ + Ca(OH)2
The number of moles of water are needed in order to produce 21.8 g of
calcium hydroxide is 0.588 moles.
How do we calculate the moles from mass?Moles of any substance will be calculated as:
n = W/M, where
W = given mass
M = molar mass
Given chemical reaction is:
CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂
Moles of 21.8g of Ca(OH)₂ = 21.8g / 74.1g/mol = 0.294mol
From the stoichiometry of the reaction, it is clear that
1 mole of Ca(OH)₂ = needed 2 moles of water
0.294 mole of Ca(OH)₂ = needed 2×0.294=0.588 moles of water
Hence required moles of water is 0.588 moles.
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Calculate the volume of hydrogen gas at 38.0 °C and 763 torr that can be produced
by the reaction of 4.33 g of zinc with excess sulfuric acid.
formula= PV = nRT
moles of Zn = 4.33 g Zn x 1 mol Zn/65.4 g
= 0.0662 moles Zn
moles H2 = 0.0662 moles Zn x 1 mol H2/mol Zn
= 0.0662 mole H2 gas
V = nRT/P
T = 38 + 273
= 311K
763 torr/760
= 1.00 atm
V = (0.0662 mol)(0.0821 Latm/Kmol)(311K)/1.00 atm
V = 1.69 L
Which of the following ions is least likely to form colored compounds?
A) V^(4+)
B) La^(3+)
C) Ti^(2+)
D) Mn^(3+)
E) Cr^(3+)
Answer:
i think d maybe correct me if im wrong
Explanation:
La³⁺ ions are colorless compounds because they have a 4f⁰ electronic configuration. Therefore, option (B) is correct.
What are lanthanoids?The lanthanide series comprises 15 metallic chemical elements with atomic numbers 57 to 71, from lanthanum through the lutetium. These elements have chemically similar elements scandium and yttrium, which are often collectively called rare-earth elements.
The chemical symbol Ln can be used to refer to any lanthanide. They are f-block elements, corresponding to the filling of the 4f-shell. All lanthanoids form trivalent cations, Ln³⁺ are determined by the ionic radius, which decreases from lanthanum to lutetium.
The valence orbitals in lanthanides have f → f transitions that are much weaker and narrower than d → d transitions. In general, the colors of lanthanide complexes are far fainter than transition metal complexes.
The electronic configuration of the lantanum is [Rn]5d¹6s². In the +3 oxidation state, it has all shells fully filled therefore, no electron transitions are possible. Therefore, La³⁺ form colorless compounds.
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compare the boiling point of water at sea leavel to the boiling point in denver (altitude = 1 mile) Explain
Answer:
boiling point decreases in denver
Explanation:
in higher places
theres less atmospheric pressure
it takes less energy to bring water to the boiling point.
Less energy means less heat
which means water will boil at a lower temperature
wonderopolisorg
Use the drop-down menus to name these structures
F
FICH
H
Answer:
What Structures??
Explanation:
Can you please explain the question more
What inference can be drawn from the graph?
A+B=C+D
45
40
35
30
25
Concentration
20
15
10
5
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Time (seconds)
OA. The reaction between A and B is reactant favored.
OB. The amount of product is greater than the amount of reactant.
OC. The reaction uses all its reactants to form products.
OD. The reaction reaches equilibrium at 1.5 seconds
OE. The amount of reactants is highest at equilibrium.
Answer:
i think its C
Explanation:
The graph indicates that the reaction reaches equilibrium around 1.5 seconds. The graph shows how the concentrations of reactants and products change over time until they eventually become constant. So, the correct option is D.
What is an Equilibrium?Equilibrium is a state in a chemical process when forward and backward reactions occur at the same rate, meaning that the concentrations of reactants and products do not change with time. In other words, the forward reaction rate equals the reverse reaction rate.
In the example above, the graph indicates that the reaction reaches equilibrium in about 1.5 seconds. The graph shows how the concentrations of reactants and products change over time until they eventually become constant. This indicates that the reaction has reached equilibrium when obtained in approximately 1.5 seconds.
So, the correct option is D.
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80.0 liters of oxygen is collected over water at 50.0 °C. The atmospheric pressure in the room is 96.00 kPa. What is the partial pressure of the oxygen?
Answer: 83.656 kpa
Explanation:
Use Dalton's law of partial pressures which states that the total pressure of a combination of gases is equal to the sum of the partial pressures of the constituent gases.
So we have,
P(total) = P(oxygen) + P(water vapour)
96.00 kpa = 12.344 + P(oxygen)
P(oxygen) = 83.656 kpa