Answer:
X(O₂) = 0.323
X(N₂) = 0.677
Explanation:
We have the partial pressures of oxygen (O₂) and nitrogen (N₂):
P(O₂) = 0.20 atm
P(N₂) = 0.80 atm
In order to solve the problem, you need the solubilities of each gas in water at 298 K. We can consider 1.3 x 10⁻³ mol/(L atm) for oxygen (O₂) and 6.8 x 10⁻⁴mol/(L atm) for nitrogen (N₂) from the bibliography.
s(O₂) = 1.3 x 10⁻³ mol/(L atm)
s(N₂) = 6.8 x 10⁻⁴mol/(L atm)
So, we calculate the concentration (C) of each gas as the product of its partial pressure (P) and the solubility (s):
C(O₂) = P(O₂) x s(O₂) = 0.20 atm x 1.3 x 10⁻³ mol/(L atm) = 2.6 x 10⁻⁴mol/L
C(N₂) = P(N₂) x s(N₂) = 0.80 atm x 6.8 x 10⁻⁴mol/(L atm) = 5.44 x 10⁻⁴ mol/L
In 1 liter of water, we have the following number of moles (n):
n(O₂) = 2.6 x 10⁻⁴ mol
n(N₂) = 5.44 x 10⁻⁴ mol
Thus, the total number of moles (nt) is calculated as the sum of the number of moles of the gases in the mixture:
nt = n(O₂) + n(N₂) = 2.6 x 10⁻⁴ mol + 5.44 x 10⁻⁴ mol = 8.04 x 10⁻⁴ mol
Finally, the mole fraction of each gas is calculated as the ratio between the number of moles of each gas and the total number of moles:
X(O₂) = n(O₂)/nt = 2.6 x 10⁻⁴ mol/(8.04 x 10⁻⁴ mol) = 0.323
X(N₂) = n(N₂)/nt = 5.44 x 10⁻⁴ mol/(8.04 x 10⁻⁴ mol) = 0.677
HC2HO3(aq)+H2O(l)⇄H3O+(aq)+C2HO3−(aq)
pKa=3.18
at 25°C
The equilibrium for the acid ionization of HC2HO3 is represented by the equation above. If 10.0mL of 0.20MHC2HO3 reacts with 5.0mL of 0.10MNaOH, which of the following could be used to calculate the correct pH of the resulting solution?
A) pH=pKa+log(0.100.20)
B) pH=pKa+log(0.0050×0.100.0100×0.20)
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
D) pH=pKa+log[((0.0050×0.10)+(0.0100×0.20)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Answer:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Explanation:
To find the pH of a buffer (The mixture of the weak acid and its conjugate base) we have to use Henderson-Hasselbalch equation:
pH = pKa + log [Base] / [Acid]
Where pKa is the pka of the buffer and [] is molar concentration of the species of the buffer
The [Base] is equal to the concentration of NaOH added:
0.10M * (0.005L / 0.015L)
And the concentration of the acid [Acid] is the initial concentration of the acid - the concentration of the NaOH added:
0.0100L * (0.20M)/0.0150L - 0.10M * (0.005L / 0.015L)
That means the pH of the buffer is:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Answer:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Explanation:
The equilibrium for the acid ionization of HC2HO3 is represented by the equation above. If 10.0mL of 0.20MHC2HO3 reacts with 5.0mL of 0.10MNaOH, which of the following could be used to calculate the correct pH of the resulting solution. pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Use the crisscross method to find the chemical formula for the ionic compound formed by aluminum (Al) and sulfur (S). A. Al₂S2 B. AlzS3 C. Al3S2 D. Als
Answer:Al2s3
Explanation:
Just took quiz
Write a balanced equation for the double-replacement precipitation reaction described, using the smallest possible integer coefficients. A precipitate forms when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. Do not include states such as (s) or (aq). It is not necessary for you to indicate which of the products is the precipitate.
Answer:
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
Explanation:
Let's consider the unbalanced equation for the reaction that occurs when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. This is a double-replacement precipitation reaction.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + NaNO₃
We will balance the equation using the trial and error method.
First, we will balance Na atoms by multiplying NaNO₃ by 2.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
As we can see, the equation is balanced.
Consider the following data on some weak acids and weak bases
acid
Ka
name formula
acetic acid
HCH3CO2
1.8 x10−5
hydrocyanic acid
HCN
4.9 x 10−10
base
Kb
name formula
pyridine
C5H5N
1.7 x 10−9
ammonia
NH3
1.8 x 10−5
Use this data to rank the following solutions in order of increasing pH. In other words, select a '1' next to the solution that will have the lowest pH, a '2' next to the solution that will have the next lowest pH, and so on.
a. 0.1M NaCH3CO2
b. 0.1M NH4Br
c. 0.1M NaBr
d. 0.1M KCN
Answer:
b < c < a < d
Explanation:
The weak acid with the lowest pKa will be the most acidic. In the other way, the conjugate base which the acid is weak will be strong.
The weak base with the lowest pKb will be the most basic. And the conjugate base of the weak base will be a strong acid.
Ka Acetic acid = 1.8x10-5
Ka HCN = 1.9x10-10
Kb pyridine = 1.7x10-9
Kb NH3 = 1.8x10-5
NH4Br is the conjugate base of a weak base. That means is a strong acid.
NH4Br has the lowest pH
NaBr is the conjugate base of a strong acid, HBr. That means NaBr is neutral
The most basic between the conjugate base of the acetic acid, NaCH3CO2 and KCN is KCN because the acetic acid is the stronger acid regard to HCN.
The rank is:
NH4Br < NaBr < NaCH3CO2 < KCN
b < c < a < d7.In the oxidation of ethane: 2 C2H6 + 7 02 + 4CO2 + 6H2O how many
liters of O2 are required to react with 90 grams of ethane?
Answer:
If reaction is taking place at room temperature and pressure(rtp)
= 360 litres of O₂ at rtp
If reaction is taking place at standard temperature and pressure(stp):
= 336 litres of O₂ at stp
Explanation:
2C₂H₆ + 70₂ → 4CO₂ + 6H₂O
1 mole of C₂H₆ = (12 × 2) + (1 × 6) = 24 + 6 = 30g
2 moles of C₂H₆ = 30 × 2 = 60g
From the equation:
1 mole of 0₂ reacts with 2 moles of C₂H₆
1 mole of 0₂ reacts with 60g of C₂H₆
? moles of 0₂ react with 90g of C₂H₆
[tex]\frac{90}{60}[/tex]= 1.5 moles of O₂
Considering condition of reaction taking place whether room temperature and pressure(rtp) or standard temperature and pressure(stp)
If room temperature and pressure(rtp):
1 mole of 0₂ occupies 24 liters/24000 cm³/ 24 dm³ of O₂
1.5 moles of O₂ occupies (24 × 1.5) litres of O₂
= 360 litres of O₂ at rtp
If standard temperature and pressure(stp):
1 mole of 0₂ occupies 22.4 liters/22400 cm³/ 22.4 dm³ of O₂
1.5 moles of O₂ occupies (22,4 × 1.5) litres of O₂
= 336 litres of O₂ at stp
how a scientist might use a graph of the
relationship between population growth and time to identify
a trend
Determine the number of electrons in an Cl ion with a charge of -3
Answer:
There are 20 electrons.
Explanation:
Chlorine has 17 electrons in its atom to begin with (you can tell from the proton number in the periodic table).
A charge of -3 means that the chlorine atom gained 3 electrons, and now needs to lose 3 electrons to return to its atom configuration.
Which of the two Lewis/electron dot structure representations, which is
the correct one for oxygen gas? PICTURE BELOW
Answer:
A
Explanation:
A mixture of He, Ar, and Xe has a total pressure of 2.40 atm. The partial pressure of He is 0.300 atm, and the partial pressure of Ar is 0.250 atm. What is the partial pressure of Xe?
Express your answer to three significant figures and include the appropriate units.
The partial pressure of Xe in the mixture is 1.850 atm. (partial pressure of Xe = Total pressure - Partial pressure of He - Partial pressure of Ar = 1.850 atm).
To find the partial pressure of Xe, we need to subtract the partial pressures of He and Ar from the total pressure.
Total pressure = partial pressure of He + partial pressure of Ar + partial pressure of Xe
Given:
Total pressure = 2.40 atm
Partial pressure of He = 0.300 atm
Partial pressure of Ar = 0.250 atm
Let's solve for the partial pressure of Xe:
Partial pressure of Xe = Total pressure - Partial pressure of He - Partial pressure of Ar
Partial pressure of Xe = 2.40 atm - 0.300 atm - 0.250 atm
Partial pressure of Xe = 1.850 atm
Therefore, the partial pressure of Xe in the mixture is 1.850 atm.
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You are performing an acid-base neutralization reaction in the laboratory to determine the concentration of an unknown base. You are supposed to titrate it with a monoprotic acid, but your lab partner accidentally fills your buret with sulfuric acid, a diprotic acid, with the same concentration as the acid called for in the experiment. How will the volume of diprotic acid compare to the volume of monoprotic acid you would have used
Answer:
Volume is reduced to half
Explanation:
Acid base titration are commonly used reactions in a lab, and are ofter used to get pH or different kind of solutions.
The neutralization of an acid base reaction is reached, when the solution (having added an indicator previously) changes its original color. chemically speaking, this occurs when the number of moles of the acid and the base are balanced and equal. In other words the following:
n₁ = n₂ (1)
This expression can also be expressed in function of concentration and volume:
M₁V₁ = M₂V₂ (2)
From here, solving for V₁:
V₁ = M₂V₂ / M₁
Now, this expression is true only when we have the same kind of substance that can lose or gain the same number of hydrogens.
Lets suppose that we have as base NaOH (Monoprotic base) and HCl (monoprotic acid), the titration reaction would be:
NaOH + HCl --------> NaCl + H₂O
As both of the species are monoprotic, the number of moles are the same when they reach the equilibrium, so, expression (2) can be used, and calculate volume or concentrations.
However, in this case, a partner made a mistake and use a diprotic acid, in this case, H₂SO₄, In this case, things chance because H₂SO₄ is diprotic, meaning that we need to dissociate two hydrogens in equilibrium, therefore, expression (2) would be something like this.
Acid: 1; Base: 2
H₂SO₄ + 2NaOH ------> Na₂SO₄ + H₂O
nH₂SO₄ = n₁ = 1
nNaOH = n₂ = 2
n₁/n₂ = 1/2
2n₁ = n₂ (3)
Writting this, in function of concentration and volume, it would be:
2M₁V₁ = M₂V₂ (4)
From here, if we solve for the volume of the acid (V₁):
V₁ = M₂V₂ / 2M₁
Therefore, according to this expression, we can see that the volume required of the acid would be half the volume required of the monoprotic acid. For example, if we need 50 mL of Chloridic acid to reach the equivalence point with NaOH, then, with H₂SO₄ it will only need 25 mL. This, of course, assuming that concentrations are the same, and volume of the base used, the same.
Hope this helps
what is the difference between transmutation and natural radioactivity
what element in magma is most abundant
Answer:
Oxygen and Silicon
Explanation:
Oxygen and Silicon are the most abundant elements in magma, SiO₂
-TheUnknownScientist
Match the element with its oxidation number (charge).
1. +1 O
2. -1 Ca
3. -3 Si
4. -2 Al
5. +2 N
6. +3 Na
7. +/- 4 F
Answer:
The answer is in the problem
Explanation:
As general rule of number of oxygen is -2:
O → -2
Alkali metals (Li, Na, K) are always +1
Na → +1
Alkali earth methals (Be, Mg, Ca...) are always +2
Ca → +2
The halogen group (F, Cl, Br...) is always -1
F → -1
The oxidation number of Si (+/- 4)
Aluminium is, usually +3
And to complete the octet rule in nitrogen, 3 electrons are required. That means:
N → -3
Balance the equation ___ CaCO3 -> ____ CaO + ____ CO2
Answer:
CaCO3 -> CaO + CO2
Explanation:
Woahhhh, did you balance it yourself just then?
Potassium nitrate, KNO3 , has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 13.3 g of KNO3 is dissolved in 213 g of water at 23.00 °C . KNO3(s)−→−−H2OK+(aq)+NO−3(aq) The temperature of the resulting solution decreases to 19.60 °X . Assume that the resulting solution has the same specific heat as water, 4.184 J/(g·°C) , and that there is negligible heat loss to the surroundings. How much heat was released by the solution
Answer:
[tex]Q_{sln}=-3219.25 J[/tex]
Explanation:
Hello there!
In this case, for this calorimetry problem, it is possible for us to infer that the heat of the reaction of dissolution of KNO3 is absorbed by the solution composed by the former and water so that we can write:
[tex]Q_{rxn}=-Q_{sln}[/tex]
Thus, given the mass, specific heat and temperature of the solution, we plug in the data to obtain the heat absorbed, by the reaction:
[tex]Q_{rxn}=-m_{sln}C_{sln}\Delta T _{sln}\\\\Q_{rxn}=-(13.3+213)g(4.184\frac{J}{yg\°C} )(19.60-23.00)\°C\\\\Q_{rxn}=3219.25J[/tex]
Also, we can say the the heat released by the solution was -3219.25 J.
Best regards!
Are sperm and egg cells exact copies of the plant cell
Answer:
No
Explanation:
thats scientifically impossible
un MODELO ATÓMICO es:
a. Una esfera con partículas positivas y negativas
b. La estructura mínima de la materia.
c. Una serie de descubrimientos.
d. La representación de un átomo donde se explica su comportamiento y características.
Answer:
Creo que es D pero no tan segura
Explanation:
PLEASE HURRY!!!
It took Mrs. Murphy 5.5 hours traveling at a rate of 113 km/hr to finally reach her parents house.
How far did she travel?
2 Which of the gases in air are elements? Explain how you can tell.
Answer:
I'll explain.
Explanation:
The molecules of two different elements, nitrogen and oxygen, make up about 99 percent of the air. The rest includes small amounts of argon and carbon dioxide. Oxygen is the life-giving element in the air. You can tell because they're on the periodic table which is a table for elements.
Explanation:
nitrogen and oxygen are the gases in the air which are elements you can simply say it by looking the periodic table
Which of the following statements about energy is FALSE?
A. Energy can be converted from one type to another.
B. The total energy of a system remains constant.
C. Energy is the capacity to do work.
D. Kinetic energy is the energy associated with its position or composition
E. Systems tend to change in order to lower their potential energy
According to law of conservation of energy, the statement which is false is kinetic energy is the energy associated with its position or composition.
According to law of conservation of energy, it is evident that energy is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.
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HELP PLISSS !!!!! what did a criminal often use to poison? A. Eye medication. B. potassium cyanide
Answer:
potassium cyanide
Explanation:
while eye medications do harm your immune system it is not enough to kill someone. criminals mainly used potassium cyanide because it was cheap. it serves as a substitute for ethanol.
PLZ HELP "NO LINKS"
A vessel of volume 22.4 dm3 contains 2.0 mol H2(g) and 1.0 mol N2(g) at 273.15 K.
(a) Calculate the mole fractions of each component.
H2:
N2:
(b) Calculate the partial pressures of each component.
H2:
N2:
(c) Calculate the total pressure.
Thanks!
Answer: (a) Mole fraction of [tex]H_{2}[/tex] is 0.66.
Mole fraction of [tex]N_{2}[/tex] is 0.33
(b) The partial pressure of [tex]H_{2}[/tex] is 1.98 atm.
The partial pressure of [tex]N_{2}[/tex] is 0.99 atm.
(c) The total pressure is 3.0 atm
Explanation:
Given: Volume = [tex]22.4 dm^{3}[/tex] (1 [tex]dm^{3}[/tex] = 1 L) = 22.4 L
Moles of [tex]H_{2}[/tex] = 2.0 mol
Moles of [tex]N_{2}[/tex] = 1.0 mol
Total moles = (2.0 + 1.0) mol = 3.0 mol
Temperature = 273.15 K
Now, using ideal gas equation the total pressure is calculated as follows.[tex]PV = nRT\\[/tex]
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
[tex]PV = nRT\\P \times 22.4 L = 3.0 mol \times 0.0821 L atm/mol K \times 273.15 K\\P = 3.0 atm[/tex]
The mole fractions of each component:The mole fraction of [tex]H_{2}[/tex] is calculated as follows.
[tex]Mole fraction = \frac{moles of H_{2}}{moles of H_{2} + moles of N_{2}}\\= \frac{2.0 mol}{(2.0 + 1.0) mol}\\= 0.66[/tex]
The mole fraction of [tex]N_{2}[/tex] is as follows.
[tex]Mole fraction = \frac{moles of N_{2}}{moles of H_{2} + moles of N_{2}}\\= \frac{1.0 mol}{(2.0 + 1.0) mol}\\= 0.33[/tex]
The partial pressures of each component:Partial pressure of [tex]H_{2}[/tex] are as follows.
[tex]P_{H_{2}} = P_{total} \times mole fraction of H_{2}\\= 3.0 atm \times 0.66\\= 1.98 atm[/tex]
Partial pressure of [tex]N_{2}[/tex] are as follows.
[tex]P_{N_{2}} = P_{total} \times mola fraction of N_{2}\\= 3.0 atm \times 0.33\\= 0.99 atm[/tex]
give same examples of ways that people destroy the plant animals relationship?
Write the balanced equation for the equilibrium reaction for the dissociation ofsilver chloride in water, and write the K expression for this reaction. Then create an ICE chart. Since we know the equilibrium concentration of the silver ion, we can solve for Ksp.Does it agree with the literature value
Answer:
See explanation
Explanation:
Hello there!
In this case, since the the concentrations are not given, and not even the Ksp, we can solve this problem by setting up the chemical equation, the equilibrium constant expression and the ICE table only:
[tex]AgCl(s)\rightleftharpoons Ag^+(aq)+Cl^-(aq)[/tex]
Next, the equilibrium expression according to the produced aqueous species as the solid silver chloride is not involved in there:
[tex]Ksp=[Ag^+][Cl^-][/tex]
And therefore, the ICE table, in which x stands for the molar solubility of the silver chloride:
[tex]\ \ \ \ \ \ \ \ \ \ \ \ \ \ AgCl(s)\rightleftharpoons Ag^+(aq)+Cl^-(aq)[/tex]
I - 0 0
C - +x +x
E - x x
Which leads to the following modified equilibrium expression:
[tex]Ksp=x^2[/tex]
Unfortunately, values were not given, and they cannot be arbitrarily assigned or assumed.
Regards!
Select the TRUE statements below regarding the coordination compound prepared in lab. Group of answer choices The coordination compound contained a complex ion that was covalently bonded to sulfate. The ligand must have at least one unshared pair of valence electrons in order to covalently bond with transition metal in the coordination compound. Ethanol was used during crystallization of the coordination compound because the compound is soluble in ethanol. The ammonia is covalently bonded to the transition metal. The colors of many coordination compounds are the result of light absorption by the d electrons on the transition metal.
Answer: Hello the compound is missing but I was able to get the Full question and missing compound . ( compound = copper sulfate )
answer : statement ; 2 , 3 and 5
Explanation:
The true statements regarding the coordination compound ( copper sulfate ) are :
The ligand must have at least one unshared pair of valence electrons in order to covalently bond with transition metal in the coordination compound ( statement 2 )Ethanol was used during crystallization of the coordination compound because the compound is soluble in ethanol ( statement 3 ) The colors of many coordination compounds are the result of light absorption by the d electrons on the transition metal ( statement 5 )During the coordination of compounds dative bonds exits between the transition metals and the Ligands molecules
Generally the ionization potential in a period increases, but there are some exceptions. The one which is not an exception is
1) Be & B 2) N & O 3) Mg & Al 4) Na & Mg
Answer:
Generally, the first ionisation energy increases along a period. But there are some exceptions one which is not an exception
When H2(g) reacts with F2(g) to form HF(g) , 542 kJ of energy are evolved for each mole of H2(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation.
Answer:
H₂(g) + F₂(g) ⇒ 2 HF(g) ΔH°rxn = -542 kJ
Explanation:
Let's consider the unbalanced equation that occcurs when H₂(g) reacts with F₂(g) to form HF(g).
H₂(g) + F₂(g) ⇒ HF(g)
In order to get the balanced equation, we will multiply HF(g) by 2.
H₂(g) + F₂(g) ⇒ 2 HF(g)
To convert a balanced equation into a thermochemical equation, we need to add the standard enthaply of the reaction, considering that 542 kJ of energy are evolved for each mole of H₂(g) and there is 1 mole of H₂(g) in the balanced equation. By convention, when energy is released, it takes a negative sign. The thermochemical equation is:
H₂(g) + F₂(g) ⇒ 2 HF(g) ΔH°rxn = -542 kJ
Which of the following contains the highest number of electrons?
OA) hydroxide ion
OB) oxonium ion
C) ammonium ion
OD) oxide ion
O E) all of them contains the same number of electrons
Determine the number of moles of CH3Br in 47.5 grams of CH3Br?
Show Work please - NO LINKS
Answer:
0.500 moles
Explanation:
In order to convert grams of any given substance into moles, we need the substance's molar mass:
Molar Mass of CH₃Br = Molar Mass of C + (Molar Mass of H)*3 + Molar Mass of BrWe can find the molar masses of each element in the periodic table:
Molar Mass of CH₃Br = 94.94 g/molNow we can divide the given mass by the molar mass in order to calculate the number of moles:
47.5 g ÷ 94.94 g/mol = 0.500 molesWhat is the correct definition of temperature
Answer:
i'm pretty sure its the last answer and if not its the 2nd one
