Answer:
A. Mass percent composition of oxygen = 58.5%
B. Mass percentage composition of oxygen = 42.1%
C. Mass percentage composition of oxygen = 72.7 %
Explanation:
Percentage mass composition of an element in a compound is given by the formula below:
Percentage mass composition = mass of element/ molar mass of compound × 100%
Percentage mass of oxygen in the given compounds are then calculated.
a. Calcium nitrate, Ca(NO₃)₂: molar mass of compound is obtained first.
Molar mass of Ca(NO₃)₂ = 40 + 14 × 2 + 16 × 2 × 3 = 164 g
Mass of oxygen = 16 × 6 = 96 g
Mass percent composition of oxygen = 96/164 × 100% = 58.5%
b. Iron (ii) sulfate, FeSO₄: molar mass of compound is obtained first.
Molar mass of FeSO₄ = 56 + 32 + 16 × 4 = 152 g
Mass of oxygen = 16 × 4 = 64 g
Mass percentage composition of oxygen = 64/152 × 100% = 42.1%
c. Carbon dioxide, CO₂: molar mass of compound is obtained first.
Molar mass of CO₂ = 12 + 16 × 2 = 44 g
Mass of oxygen = 16 × 2 = 32 g
Mass percentage composition of oxygen = 32/44 × 100% = 72.7 %
A) The average molecular speed in a sample of Ar gas at a certain temperature is 391 m/s. The average molecular speed in a sample of Ne gas is ______ m/s at the same temperature.
B) The rate of effusion of Xe gas through a porous barrier is observed to be 7.03×10-4 mol / h. Under the same conditions, the rate of effusion of SO2 gas would be ______ mol / h
Answer:
For A: The average molecular speed of Ne gas is 553 m/s at the same temperature.
For B: The rate of effusion of [tex]SO_2[/tex] gas is [tex]1.006\times 10^{-3}mol/hr[/tex]
Explanation:
For A:
The average molecular speed of the gas is calculated by using the formula:
[tex]V_{gas}=\sqrt{\frac{8RT}{\pi M}}[/tex]
OR
[tex]V_{gas}\propto \sqrt{\frac{1}{M}}[/tex]
where, M is the molar mass of gas
Forming an equation for the two gases:
[tex]\frac{V_{Ar}}{V_{Ne}}=\sqrt{\frac{M_{Ne}}{M_{Ar}}}[/tex] .....(1)
Given values:
[tex]V_{Ar}=391m/s\\M_{Ar}=40g/mol\\M_{Ne}=20g/mol[/tex]
Plugging values in equation 1:
[tex]\frac{391m/s}{V_{Ne}}=\sqrt{\frac{20}{40}}\\\\V_{Ne}=391\times \sqrt{2}=553m/s[/tex]
Hence, the average molecular speed of Ne gas is 553 m/s at the same temperature.
For B:
Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of the molar mass of the gas. The equation for this follows:
[tex]Rate\propto \frac{1}{\sqrt{M}}[/tex]
Where, M is the molar mass of the gas
Forming an equation for the two gases:
[tex]\frac{Rate_{SO_2}}{Rate_{Xe}}=\sqrt{\frac{M_{Xe}}{M_{SO_2}}}[/tex] .....(2)
Given values:
[tex]Rate_{Xe}=7.03\times 10^{-4}mol/hr\\M_{Xe}=131g/mol\\M_{SO_2}=64g/mol[/tex]
Plugging values in equation 2:
[tex]\frac{Rate_{SO_2}}{7.03\times 10^{-4}}=\sqrt{\frac{131}{64}}\\\\Rate_{SO_2}=7.03\times 10^{-4}\times \sqrt{\frac{131}{64}}\\\\Rate_{SO_2}=1.006\times 10^{-3}mol/hr[/tex]
Hence, the rate of effusion of [tex]SO_2[/tex] gas is [tex]1.006\times 10^{-3}mol/hr[/tex]
Aqueous potassium carbonate was mixed with aqueous copper (1) fluoride and a crystallized copper (1) carbonate product was formed. A crystalized product is a solid. The other product, potassium fluoride, remains dissolved in solution. Consider the other product and it’s phase, and then write the balanced molecular equation for this precipitation reaction. Express your answer as a chemical equation including phases. Type an underscore (_) or a carat (^) to add subscripts and superscripted more quickly.
Answer: The balanced molecular equation for the precipitation reaction is [tex]K_2CO_3(aq)+2CuF(aq)\rightarrow Cu_2CO_3(s)+2KF(aq)[/tex]
Explanation:
A precipitation reaction is defined as the reaction where a solid precipitate (solid substance) is formed at the end of the reaction. It is insoluble in water.
When potassium carbonate reacts with copper (I) fluoride, it leads to the formation of solid copper (I) carbonate and potassium fluoride solution.
The balanced chemical equation follows:
[tex]K_2CO_3(aq)+2CuF(aq)\rightarrow Cu_2CO_3(s)+2KF(aq)[/tex]
The precipitate formed is copper (I) carbonate
I NEED THIS NOW AND NO LINKS OR ILL REPORT
Which material creates the most waste and pollutants when creating one
ton of bottles? *
aluminum
glass
plastic
Answer:
plastic
........................
Calculate the number of moles
309 grams of (SF)4 = how many moles of (SF)4
Answer:
2.85 mol
Explanation:
Step 1: Given data
Mass of sulfur tetrafluoride (SF₄): 309 g
Step 2: Calculate the number of moles corresponding to 309 g of sulfur tetrafluoride
To convert mass to moles we need a conversion factor: the molar mass. The molar mass of SF₄ is 108.07 g/mol.
309 g × 1 mol/108.07 g = 2.85 mol
The sloth is able to camouflage by moving really slowly and
A. changing colors
B. hanging upside down
D. having fur that is a similar color to tree barks with algae growing on it
Answer:
D. having fur that is a similar color to tree barks with algae growing on it
Explanation:
Choice A doesnt make sense because sloths do not change colors, and hanging upside down would not protect you from prey or blend in. D matches the description of a sloth.
Answer:
Having fur that is a similar color to tree barks with algae growing on it.
Explanation:
Calculate the number of milliliters of 0.587 M NaOH required to precipitate all of the Fe3 ions in 197 mL of 0.654 M FeCl3 solution as Fe(OH)3. The equation for the reaction is: FeCl3(aq) 3NaOH(aq) Fe(OH)3(s) 3NaCl(aq)
Answer: The number of milliliters of 654 mL for 0.587 M NaOH required to precipitate all of the [tex]Fe^{3+}[/tex] ions in 197 mL of 0.654 M [tex]FeCl_{3}[/tex] solution as [tex]Fe(OH)_{3}[/tex].
Explanation:
The reaction equation is as follows.
[tex]FeCl_{3}(aq) + 3NaOH(aq) \rightarrow Fe(OH)_{3}(s) + 3NaCl(aq)[/tex]
Therefore, moles of [tex]Fe(OH)_{3}[/tex] are calculated as follows.
Moles = Molarity of [tex]Fe(OH)_{3}[/tex] [tex]\times[/tex] Volume (in L)
= 0.654 M [tex]\times[/tex] 0.197 L
= 0.128 mol
Now, according to the given balanced equation 1 mole of [tex]FeCl_{3}(aq)[/tex] reacts with 3 moles of NaOH(aq). Hence, moles of [tex]Fe(OH)_{3}[/tex] reacted are calculated as follows.
3 [tex]\times[/tex] 0.128 mol = 0.384 moles of NaOH
As moles of NaOH present are as follows.
Moles of NaOH = Molarity of NaOH [tex]\times[/tex] Volume (in L)
0.384 mol = 0.587 M [tex]\times[/tex] Volume (in L)
Volume (in L) = 0.654 L (1 L = 1000 mL) = 654 mL
Thus, we can conclude that the number of milliliters of 654 mL for 0.587 M NaOH required to precipitate all of the [tex]Fe^{3+}[/tex] ions in 197 mL of 0.654 M [tex]FeCl_{3}[/tex] solution as [tex]Fe(OH)_{3}[/tex].
g Using Newman projections, draw the most stable conformation for each of the following compounds. (a) 3-methyl pentane, viewed along the C2-C3 bond (b) 3,3-dimethyl hexane, viewed along the C3-C4 bond
Answer:
Using Newman projections, draw the most stable conformation for each of the following compounds.
(a) 3-methyl pentane, viewed along with the C2-C3 bond.
(b) 3,3-dimethyl hexane, viewed along with the C3-C4 bond.
Explanation:
(a) The structure of 3-methyl pentane is shown below:
In Newman projection, the most stable conformation is staggard conformation.
In staggard conformation, the torsional strain is very less compared to eclipsed conformation.
(b)3,3-dimethyl hexane, viewed along with the C3-C4 bond.
Which of the following is not a polymer
A. Glucose.
B. Starch.
C. Cellulose.
D. DNA.
Answer:
A. Glucose
Explanation:
Glucose is a monomer and not a polymer. So, option (A) is not a polymer.
Glucose is not a polymer because it is a kind of molecule while Starch , cellulose and DNA are polymers.
The correct answer is option A. Glucose.
How many significant figures are in a measurement of 28.050 km?
Answer:
has 5, ans 3 decimals.
thats as simple as i can put it.
163 mL of 2.75 mol/L aluminum sulfate is to have all aluminum ions removed by adding a 3.65 mol/L sodium sulfide solution.
Al2(SO4)3(aq) + 3 Na2S(aq) → Al2S3(s) + 3 Na2SO4(aq)
What is the minimum volume of sodium sulfide that must be added to completely remove all the aluminum ions? What mass of aluminum sulfide will form?
Answer:
[tex]V_{Na_2S}=368mL[/tex]
[tex]m_{Al_2S_3}=67.3gAl_2S_3[/tex]
Explanation:
Hello there!
In this case, according to the given information, it is possible to realize that the only way for us to calculate the required volume of sodium sulfide, is by calculating the moles of this substance consumed 163 mL of 2.75 mol/L aluminum sulfate by using the definition of molar concentration and the 1:3 mole ratio between these two:
[tex]n_{Na_2S}=0.163L*2.75\frac{molAl_2(SO_4)_3}{L}*\frac{3molNa_2S}{1molAl_2(SO_4)_3} =1.34molNa_2S[/tex]
Now, we divide these moles by the molar concentration of sodium sulfide to obtain the required volume:
[tex]V_{Na_2S}=\frac{1.34molNa_2S}{3.65mol/L} =0.368L=368mL[/tex]
For the last part, we now use the 1:1 mole ratio of aluminum sulfate to aluminum sulfide and the molar mass of the latter (150.158 g/mol) in order to calculate the required mass:
[tex]m_{Al_2S_3}=0.163L*2.75\frac{molAl_2(SO_4)_3}{L}*\frac{1molAl_2S_3}{1molAl_2(SO_4)_3} *\frac{150.158gAl_2S_3}{1molAl_2S_3} \\\\m_{Al_2S_3}=67.3gAl_2S_3[/tex]
Regards!
A central idea in modern quantum mechanics is:
(4 Points)
A wave character exhibited by all particles.
The acceleration of charged particles moving around a nucleus.
The opportunity to locate the position of an electron exactaly.
The continuous range of energies that electrons can have.
Answer:
A wave character exhibited by all particles
Explanation:
The central idea in quantum mechanics is the paradox of wave-particle duality. In quantum mechanics, all particles are believed to also exhibit wavelike characters.
The electron is assumed to behave as a wave hence its position can not be precisely determined according the Heisenberg's uncertainty principle.
These are the underlying postulates that informed Erwin Schrödinger's wave mechanical model of the atom.
Hence, the basic postulate of quantum mechanics is that a wave character is exhibited by all particles.
Calculate the mass in grams of 24.5 mL of diethyl ether, an anesthetic that has a density of 0.713 g/mL. Round your answer to the tenth's place.
Answer:
17.48
Explanation:
mass=density×volume
= 0.713g/ml × 24.5 ml
= 17.4685
≈ 17.47
Why do powders react faster than lumps?
1)Particles of a powder have a lower activation energy
2)Collisions between reactant particles are more frequent
3)Particles of a powder move faster
The more finely divided the solid is, the faster the reaction happens. A powdered solid will normally produce faster reaction than if the same mass is present as a single lump. The powdered solid has a greater surface than the single lump
Explanation:
Mark as brainlist
Element compound2. Select all the compounds from the following elements
HE
Fe2O3
O2
P4
C2H4O2
Answer: [tex]Fe_2O_3[/tex] and [tex]C_2H_4O_2[/tex] are the compounds.
Explanation:
A chemical compound is defined as a chemical substance that is formed by the combination of two or more atoms of different elements which cannot be separated by any physical means but when chemically treated, they decompose into their parent elements.
For example, water is made up of hydrogen and oxygen. This compound is a liquid and its individual components are gases. When water is decomposed, it forms hydrogen and oxygen gas.
For the given options:
He(Helium) is an element formed by the combination of only type of atoms.
[tex]O_2[/tex] and [tex]P_4[/tex] are molecules of same element.
[tex]Fe_2O_3[/tex] is a compound fomed by the combination of iron and oxygen atoms.
[tex]C_2H_4O_2[/tex] is a compound fomed by the combination of carbon, hydrogen, and oxygen atoms.
Hence, [tex]Fe_2O_3[/tex] and [tex]C_2H_4O_2[/tex] are the compounds.
El agua del mar contiene aproximadamente un 3,0 % m/v de sal (NaCl, 58,44 g/mol), (asuma que es la única fuente de cloruros) si una fábrica de baterías para carro provoca un derrame de material con plomo(II). La concentración máxima (en g/L) de plomo(II) que puede contener el agua marina es:_______________
Kps=1,6x10^5
Answer:
s = 4.41 g/L.
Explanation:
¡Hola!
En este caso, considerando el escenario dado, se hace necesario para nosotros saber que la posible reacción de disociación la experimenta el cloruro de plomo (II) como se muestra a continuación:
[tex]PbCl_2(s)\rightleftharpoons 2Cl^-(aq)+Pb^{2+}(aq)[/tex]
Lo cual hace que la expresión de equilibrio se calcule como:
[tex]Ksp=[Pb^{2+}][Cl^-]^2[/tex]
Y que en términos de la solubilidad molar, s, se resuelve como:
[tex]1.6x10^{-5}=s(2s)^2\\\\1.6x10^{-5}=4s^3\\\\s=\sqrt[3]{\frac{1.6x10^{-5}}{4} } \\\\s=0.0159molPbCl_2/L[/tex]
Ahora, convertimos este valor a g/L al multiplicarlo por la masa molar del cloruro de plomo (II):
[tex]s=0.0159molPbCl_2/L*\frac{278.1gmolPbCl_2}{1molmolPbCl_2} \\\\s=4.41g/L[/tex]
¡Saludos!
(iii) Give areason why the nitrogen gas obtained is not pure
Answer:
jhhhhhhhhh
Explanation:
dffffffffffffg
How do scientists test their ideas
What is the purpose of the scientific method
What is the pH of 0.6 M NaOH?
Answer:
pOH = - log[OH-]
[OH-] = 0.6M
[tex]pOH \: = - log(0.6) \\ = 0.2218487496 \\ pH \: + pOH \: = 14 \\ pH \: + 0.221848749 = 14 \\ pH = 14 - 0.221848749 \\ = 13.77815125 \\ 13.8[/tex]
It is important for scientists to know how much energy is given off or absorbed in a chemical reaction. Which options below would indicate an exothermic reaction?
delta H = –
delta H = +
Energy is considered a reactant in the reaction: A + B + energy ---> C + D
Energy is considered a product in the reaction: A + B ---> C + D + energy
Energy is released in the reaction.
Energy is absorbed in the reaction.
For exothermic reactions, ΔH is always negative, energy is considered a product, and energy is released in the reaction.
An exothermic reaction is one in which energy, usually in the form of heat, is released to the environment from the reaction. In other words, the final temperature of an exothermic reaction would always be more than the initial temperature.
This also means that heat energy is a product of exothermic reactions and this heat is released to the environment from the reaction.
More on exothermic reactions can be found here: https://brainly.com/question/10373907?referrer=searchResults
Answer:
a, d, and e is correct on edge of the nuity
Explanation:
have a good day
We can determine the potential of a single electrode by:____________.
a. attaching it to a voltmeter
b. determining the electronegativity of its component elements
c. measuring its mass
d. none of the above
Answer:
d. none of the above
Explanation:
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
The potential of a single electrode in a half-cell is called the Single electrode potential.
The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
However, there is no way of measuring the emf of a single half-cell directly.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Therefore, the correct option is D "none of the above"
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
What is an electrochemical cell?
An electrochemical cell is a device that can generate electrical energy from the chemical reactions occurring in it, or use the electrical energy supplied to it to facilitate chemical reactions in it.
The potential of a single electrode in a half-cell is called the Single electrode potential.The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Hence the correct option is D.
Learn more about electrochemical cell here:
https://brainly.com/question/12034258
#SPJ1
Use the graph to calculate the instantaneous rate of formation of HBr at 50 s
Express your answer using one significant figure.
Answer: The instantaneous rate of formation of HBr at 50 s is [tex]1.4\times 10^{-2}M/s[/tex]
Explanation:
From the graph,
Initial rate of the [tex]Br_2[/tex] = 1.0 M
Time when the concentration of [tex]Br_2[/tex] is 0.5 M (half the concentration ) = 60 sec
For first order reaction:
Calculating rate constant for first order reaction using half life:
[tex]t_{1/2}=\frac{0.693}{k}[/tex] .....(1)
[tex]t_{1/2}[/tex] = half life period = 60 s
k = rate constant = ?
Putting values in equation 1:
[tex]k=\frac{0.693}{60s}\\\\k=0.01155s^{-1}[/tex]
For the given chemical reaction:
[tex]H_2(g)+Br_2(g)\rightarrow 2HBr(g)[/tex]
Rate of the reaction = [tex]-\frac{\Delta [Br_2]}{\Delta t}=\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}[/tex]
Negative sign represents the disappearance of the reactants
From the above expression:
[tex]k[Br_2]=-\frac{\Delta [Br_2]}{\Delta t}=\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}[/tex]
At 50 seconds, [tex][Br_2]=0.6 M[/tex]
Plugging values in above expression, we get:
[tex]\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}=0.01155\times 0.6\\\\\frac{\Delta [HBr]}{\Delta t}=2\times 0.01155\times 0.6=0.01386=1.4\times 10^{-2}M/s[/tex]
Hence, the instantaneous rate of formation of HBr at 50 s is [tex]1.4\times 10^{-2}M/s[/tex]
How many molecules are in 0.5 grams of ammonia, NH3?
Answer:
I dont no ma men
Explanation:
Sorry cause a dont no
Which of the following material is the weakest thermal conducters
Determine which intermolecular forces are the dominant (strongest) forces for a pure sample of each of the following molecules by placing the molecules into the correct bins.
Dispersion Forces; Dipole-Dipole Forces; Hydrogen Bonding Forces
Kr, H2O, CHCI3, HF, C2H6, HBr
Answer:
Kr- Dispersion Forces
H2O- Hydrogen Bonding
CHCI3- Dipole-Dipole Forces
HF- Hydrogen Bonding
C2H6- Dispersion Forces
HBr- Hydrogen Bonding Forces
Explanation:
Dispersion forces occurs in all substances. They are the dominant intermolecular interaction in all non polar substances such as C2H6 and Kr.
Hydrogen bonding occurs when hydrogen is bonded to a highly electronegative atom such as Cl, Br, O etc. It is the dominant intermolecular interaction in HF, HBr and H2O.
Dipole-Dipole interactions occur when a permanent dipole exists in a molecule such as in CHCI3
Cyclopropane is more reactive than most cycloalkanes. What factors lead to cyclopropane being less stable than the other cycloalkanes
Answer: The factor that lead to cyclopropane being less stable than the other cycloalkanes is the presence of a RING STRAIN.
Explanation:
In organic chemistry, the end carbon atoms of an open aliphatic chain can join together to form a closed system or ring to form cycloalkanes. Such compounds are known as cyclic compounds. Examples include cyclopropane, cyclobutane, cyclopentane and many among others.
Cyclopropane is less stable than other cycloalkanes mentioned above because of the presence of ring strain in its structural arrangement. The ring strain is the spatial orientation of atoms of the cycloalkane compounds which tend to give off a very high and non favourable energy. The release of heat energy which is stored in the bonds and molecules cause the ring to be UNSTABLE and REACTIVE.
The presence of the ring strain affects mainly the structures and the conformational function of the smaller cycloalkanes. cyclopropane, which is the smallest cycloalkane than the rest mentioned above, contains only 3 carbons with a small ring.
A substance with two oxygen atoms is combined with a substance with one oxygen atom to form one product. What is true of the product?
There will be no oxygen in the product. Some of the oxygen will evaporate into the air.
A solution made by dissolving 9.81 g of a nonvolatile, nonelectrolyte in 90.0 g of water boiled at 100.37 °C at 760 mm Hg. What is the molar mass of the substance? [kp = 0.51 °c/m]
Answer:
151 g/mol
Explanation:
In order to solve this problem we need to keep in mind the formula for the boiling point elevation:
ΔT = Kb * m * iWhere:
ΔT is the temperature difference between the boiling point of the solution and that of pure water. 100.37 °C - 100.00 °C = 0.37 °C.m is the molarity of the solutioni is the van't Hoff factor. As the solute is a nonelectrolyte, the factor is 1.Input the data and calculate m:
0.37 °C = 0.51 °C/m * m * 1 m =0.72 mWe now can calculate the number of moles of the substance, using the definition of molarity:
molarity = moles of solute / kg of solventIn this case kg of solvent = 90.0 g / 1000 = 0.090 kg
0.72 m = moles / 0.090 kgmoles = 0.065 molFinally we calculate the molar mass, using the number of moles and the mass:
9.81 g / 0.065 mol = 151 g/molOnce the race had been completed, the students opened their canisters to see if anything remained inside. They wanted to decide if they should modify their techniques for another race. Designs 1, 2, and 3 all still had some solid Alka-Selzter residue in the canister. Design 4 did not. The teacher asked the students to analyze their results as an engineer would. What worked well in the design? What could be improved? Predict what Design Team 3 decided to change.
A)Use hot water
B)Use more water
C)Not to crush the tablet and to use hot water
D)Not to crush the tablet and to use more water
HURRY! GIVING BRAINLY
Answer:
a
Explanation:because i did the test
heating curve shows temperature verses energy gain. Which parts of the curve represent a gain in potential energy?
100
Temperature (°C)
0
Increasing Energy
Answer:
Those two horizontal lines.
Explanation:
Hello there!
In this case, when focusing on these heating curves, it is important to say they tend to have two constant-temperature sections and three variable-temperature sections. Thus, from lower to higher temperature, the first constant-temperature section corresponds to melting and the second one vaporization, whereas the three variable-temperature sections correspond to the heating of the solid until melting, the liquid until vaporization and the gas until the critical point.
In such a way, we infer that the boxes referred to constant temperature are referred to a gain in potential energy, that is, the two horizontal lines.
Regards!
Answer: My sacrifica has been made.
Explanation: