Answer:
0.677 moles
Explanation:
Take the atomic mass of K = 39.1, O =16.0, P = 31.0
no. of moles = mass / molar mass
no. of moles of K3PO4 used = 4.79 / (39.1x3 + 31 + 16x4)
= 0.02256 mol
From the equation, the mole ratio of KOH : K3PO4 = 3 :1,
meaning every 3 moles of KOH used, produces 1 mole of K3PO4.
So, using this ratio, let the no. of moles of KOH required to be y.
[tex]\frac{3}{1} =\frac{y}{0.02256} \\[/tex]
y = 0.02256 x3
y = 0.0677 mol
If you don't find exactly 0.677 moles as one of the options, go for the closest one. A very slight error may occur because of taking different significant figures of atomic masses when calculating.
The reaction, 2 SO3(g) <--> 2 SO2(g) + O2(g) is endothermic. Predict what will happen if the temperature is increased.
Explanation:
This reaction is in equilibrium and would hence obey lechatelier's principle. This principle states that whenever a system at equilibrium undergoes a change, it would react in way so as to annul that change.
Since it is an endothermic reaction, increasing the temperature would cause the reaction to shift towards the right.
This means that it favours product formation and more of the product would be formed.
Iron(II) is available to bond with chloride ion. How many of each type of ion will bond to form an ionic compound?
A) 3 iron(II), 1 chloride
B) 2 iron(II), 3 chloride
C) 2 iron(II), 1 chloride
D) 1 iron(II), 2 chloride
Answer:
D) 1 iron(II), 2 chloride
Explanation:
Iron II chloride is the compound; FeCl2. It is formed as follows, ionically;
Fe^2+(aq) + 2Cl^-(aq) -----> FeCl2
The formation of one mole of FeCl2 involves the reaction one mole of iron and two moles of chloride ions. This means that in FeCl2, the ratio of iron to chlorine is 1:2 as seen above.
Therefore there is one iron II ion and two chloride ions in each mole of iron II chloride, hence the answer.
Decide which element probably has a density most and least similar to the density of lithium.
Answer:
Helium and potassium
Explanation:
The density of helium is 0.18 and potassium 0.86, while lithium is 0.53
What is a major product of the reaction in the box?
Answer:
Molecule C
Explanation:
In this case, on the first reaction, we will have the production of a Grignard reagent. This molecule will react with [tex]D_2O[/tex] and a deuterium atom will be transferrred to the benzene ring. Then at the top of the molecule, we will have an acetal structure. This acetal can be broken by the action of the acid [tex]DCl[/tex], In the mechanism at the end, we will obtain a carbonyl group bonded to a hydrogen atom. Therefore we will have in the final product the aldehyde group. See figure 1 to further explanations.
I hope it helps!
Draw a Lewis structure for one important resonance form of HBrO4 (HOBrO3). Include all lone pair electrons in your structure. Do not include formal charges in your structure.
Answer:
The Lewis structure is attached with the answer -
Explanation:
Lewis structure or Lewis dot diagram are diagrams or representation of showing the bonding between different or same atoms of a molecule in any and also shows lone pairs of electrons that may exist in the molecule as dots.
HBrO₄ is bromine oxoacid which is also known as perbromic acid. It is a unstable inorganic compound.
The Lewis structure is attached in form of image with representation of lone pairs of electrons.
Nylon 88 is made from the monomers H2N(CH2)8NH2 and HOOC(CH2)6COOH. So, would you characterize nylon 88 as rather an addition or a condensation polymer? Please explain your answer.
Answer:
Combination of H2N(CH2)8NH2 and HOOC(CH2)6COOH leads to the loss of water molecules at each linkage position.
Explanation:
A condensation polymer is a polymer formed when two monomers combine with the elimination of a small molecule such as water. The removal of the small molecule occurs at the point where the two monomers are joined to each other.
Nylon is known to form condensation polymers. This is because it involves the linkage of an -OH group to an -NH2 group. Water is eliminated in the process.
In the case of H2N(CH2)8NH2 and HOOC(CH2)6COOH, linkage of the both monomers at the 8 position of each chain leads to the formation of nylon- 8,8 with loss of water molecules at each linkage position. This stepwise loss of water molecules at each linkage makes it a condensation polymer.
Which types of electron orbitals will have higher energy than a 4d orbital?
A) 4p
B) 3s
C) 5s
D) 4f
Answer:
D) 4f
Explanation:
To determine which electron orbital that will have higher energy than a 4d orbital, we write the electron configuration starting with s-orbital.
1s
2s 2p
3s 3p 3d 3f
4s 4p 4d 4f
5s 5p 5d 5f
6s 6p 6d 6f
7s 7p 7d 7f
In ascending order, 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 3f, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, 6f, 7d, 7f.
From the electronic configuration formula above, the electron orbitals that have higher energy than a 4d orbital are 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, 6f, 7d, 7f.
Therefore, 4f is the correct answer.
Answer:
D) 4f
Explanation:
If the H+ concentration is 0.00001 M, what is the OH- concentration?
Answer:
1.00x10^-9
Explanation:
Calculate the equilibrium concentrations of N2O4 and NO2 at 25 ∘C in a vessel that contains an initial N2O4 concentration of 0.0655 M . The equilibrium constant Kc for the reaction N2O4(g)⇌2NO2(g) is 4.64×10−3 at 25 ∘C. Express your answers using four decimal places separated by a comma.
Answer:
[N2O4] = 0.0573M
[NO2] = 0.0163M
Explanation:
The equilibrium of N2O4 is:
N2O4(g)⇌2NO2(g)
Where Kc is defined as:
Kc = 4.64x10⁻³ = [NO2]² / [N2O4]
When you add just N2O4, the reaction will occurs until [NO2]² / [N2O4] = 4.64x10⁻³. Here, the system reaches equilibrium.
That means if 0.0655M N2O4 begin reaction, in equilibrium we will have:
[N2O4] = 0.0655M - X
[NO2] = 2X
Where X is defined as reaction coordinate
Replacing in Kc:
4.64x10⁻³ = [NO2]² / [N2O4]
4.64x10⁻³ = [2X]² / [0.0655-X]
3.0392x10⁻⁴ - 4.64x10⁻³X = 4X²
3.0392x10⁻⁴ - 4.64x10⁻³X - 4X² = 0
Solving for X:
X = -0.0093 → False solution. there is no negative concentrations
X = 0.008156M → Right solution.
Replacing X, equilibrium concentrations are:
[N2O4] = 0.0655M - X
[NO2] = 2X
[N2O4] = 0.0573M[NO2] = 0.0163MSolid iron(II) oxide reacts with oxygen gas to produce solid iron(III) oxide. Balance the equation for this reaction (in lowest multiple integers). Write the unbalanced equation for this reaction.
Answer
Hello
I think the reaction is like this FeO+OFe²O³
And the balance reaction is 2Fe+OFe²O³
Explanation:
At first we should find sth that has more atoms than the other then for example we realized that we have two atoms of Fe in Fe²O³ then put 2 before FeO and now we have 2 atoms of Fe in right side and 2 atoms of Fe in left then Oxygen in FeO change to 2 atoms of Oxygen and we have an other one in right side that they become 3 atoms of Oxygen and now we have 3 atoms of Oxygen in both right and left side.
Finally our reaction balanced.
Good luck
Find the [OH−] of a 0.32 M methylamine (CH3NH2) solution. (The value of Kb for methylamine (CH3NH2) is 4.4×10−4.) Express your answer to two significant figures and include the appropriate units.
Answer:
[tex][OH^-]=0.01165M[/tex]
Explanation:
Hello,
In this case, for the dissociation of methylamine:
[tex]CH_3NH_2(aq)+H_2O(l)\rightleftharpoons CH_3NH_3^+(aq)+OH^-(aq)[/tex]
We can write the basic dissociation constant as:
[tex]Kb=\frac{[CH_3NH_3^+][OH^-]}{[CH_3NH_2]}[/tex]
That in terms of the reaction extent [tex]x[/tex], turns out:
[tex]Kb=\frac{x*x}{[CH_3NH_2]_0-x}[/tex]
[tex]4.4x10^{-4}=\frac{x^2}{0.32M-x}[/tex]
That has the following solution for [tex]x[/tex]:
[tex]x_1=-0.01209M\\x_2=0.01165M[/tex]
Yer 0.01165M is valid only as no negative concentrations are eligible. It means that it is the concentration of hydroxyl ions in the solution:
[tex][OH^-]=0.01165M[/tex]
Best regards.
1. Define the Law of Conservation of Mass (via text). Now that you’ve defined this law, explain what it means in your own words using an example.
Explanation:
The law of conservation of mass states that mass can neither be created nor be destroyed.
Explanation in own words = this means that in this universe no one can create or destroy mass.
No physical or chemical force.
Review the reversible reactions given, along with the associated equilibrium constant Kat room temperature. In each case, determine whether the forward or reverse reaction is favored.
CH3COOH → CH3C00^- + H^+
Ka=1.8 x 10^-5
AgCl → Ag^+ + Cl^-
Ksp=1.6 x 10^-10
Al(OH)3 → Al^3+ + 3OH^-
Ksp=3.7 x 10^-15
A+B → C
K=4.9 x 10^3
Answer:
The answers to your questions are given below
Explanation:
The following data were obtained from the question:
CH3COOH → CH3C00^- + H^+
Equilibrium constant, Ka = 1.8 x 10^-5
AgCl → Ag^+ + Cl^-
Equilibrium constant, Ksp = 1.6 x 10^-10
Al(OH)3 → Al^3+ + 3OH^-
Equilibrium constant, Ksp = 3.7 x 10^-15
A+B → C
Equilibrium constant, K = 4.9 x 10^3
When the value of the equilibrium constant is grater than 1, it shows that the concentration of product is higher than that of the reactant and it implies that the forward reaction is favored.
When the value of the equilibrium constant is 1, it shows that the the concentration of the product and reactant are the same. Therefore neither the forward nor the reverse reaction is favored.
When the value of the equilibrium constant is lesser than 1, it shows that the concentration of the reactant is higher than the concentration of the product. Therefore, the reversed reaction is favored.
Now, we shall the question given above as follow:
A. CH3COOH → CH3C00^- + H^+
Equilibrium constant, Ka = 1.8 x 10^-5
Since the value of the equilibrium constant is lesser than 1, it means that the reverse reaction is favored.
B. AgCl → Ag^+ + Cl^-
Equilibrium constant, Ksp = 1.6 x 10^-10
Since the value of the equilibrium constant is lesser than 1, it means that the reverse reaction is favored.
C. Al(OH)3 → Al^3+ + 3OH^-
Equilibrium constant, Ksp = 3.7 x 10^-15
Since the value of the equilibrium constant is lesser than 1, it means that the reverse reaction is favored.
D. A+B → C
Equilibrium constant, K = 4.9 x 10^3
Since the value of the equilibrium constant is greater than 1, it means that the forward reaction is favored.
The reaction conditions are:
A. The reverse reaction is favored.
B. The reverse reaction is favored.
C. The reverse reaction is favored.
D. The forward reaction is favored.
Chemical reaction:
A. [tex]CH_3COOH[/tex] → [tex]CH_3COO^- + H^+[/tex]
Equilibrium constant, Ka = [tex]1.8 * 10^{-5}[/tex]
B. [tex]AgCl[/tex] → [tex]Ag^+ + Cl^-[/tex]
Equilibrium constant, Ksp = [tex]1.6 * 10^{-10}[/tex]
C. [tex]Al(OH)_3[/tex] → [tex]Al^{3+} + 3OH^-[/tex]
Equilibrium constant, Ksp = [tex]3.7 * 10^{-15}[/tex]
D. A+B → C
Equilibrium constant, K = [tex]4.9 * 10^3[/tex]
Conditions for Equilibrium constant:When the value of the equilibrium constant is greater than 1, it shows that the concentration of product is higher than that of the reactant and it implies that the forward reaction is favored.
When the value of the equilibrium constant is 1, it shows that the the concentration of the product and reactant are the same. Therefore neither the forward nor the reverse reaction is favored.
When the value of the equilibrium constant is lesser than 1, it shows that the concentration of the reactant is higher than the concentration of the product. Therefore, the reversed reaction is favored.
Thus, the reactions will be:
A. The reverse reaction is favored.
B. The reverse reaction is favored.
C. The reverse reaction is favored.
D. The forward reaction is favored.
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What is it’s molecular formula for C5H4 if it’s molar mass is 128.17g/mol
✔ C5H4 has a molecular molar mass of :
M(C5H4) = 5 x M(C) + 4 x M(H)
M(C5H4) = 5 x 12 + 4 x 1 M(C5H4) = 60 + 4 M(C5H4) = 64 g/mol✔ The molecular mass of C5H4 is therefore 64 g/mol.
But, 128/64 = 2 This is double the molar mass of C5H4, this molecule has the formula 2C5H4.Answer:
C10H8
Explanation:
I clicked on that answer, and it is correct.
The second-order decomposition of HI has a rate constant of 1.80 · 10-3 M-1s-1. How much HI remains after 27.3 s if the initial concentration of HI is 4.78 M?
Answer: 3.87M of HI remains after 27.3 s
Explanation:
Using the Second order decomposition equation of
1/[H]t =K x t +1/[A]o
Given initial concentration ,[A]o = 4.78M
time, t = 27.3 s
rate of constant , k= 1.80 x 10^-3 M-1s-1
1/[H] t= 1/[A] t= concentration after time, t=?
SOLUTION
1/[A] t =kt +1/[A]o
1/[A] t =(1.80 x 10^-3 (27.3)+1/4.78
0.04914+0.2092=0.2583
1/[A] t =0.2583
[A] t =1/0.2583= 3.87M
Determine the volume occupied by 10 mol of helium at
27 ° C and 82 atm
Answer:
3.00 L
Explanation:
PV = nRT
(82 atm × 101325 Pa/atm) V = (10 mol) (8.314 J/mol/K) (27 + 273) K
V = 0.00300 m³
V = 3.00 L
Using the Bohr model, determine the lowest possible energy, in joules, for the electron in the Li2+ ion.
Answer: E = - 19.611×[tex]10^{-18}[/tex] J
Explanation: The lowest possible energy can be calculated using the formula:
[tex]E_{n} = - Z^{2}.\frac{k}{n^{2}}[/tex]
where:
Z is atomic number of the atom;
k is a constant which contains other constants and is 2.179×[tex]10^{-18}[/tex] J
n is a layer;
For the lowest possible, n=1.
Atom of Lithium has atomic number of Z=3
Substituing:
[tex]E_{1} = - 3^{2}.\frac{2.179.10^{-18}}{1}[/tex]
[tex]E_{1} =[/tex] [tex]-19.611.10^{-18}[/tex] J
The energy for the electron in the [tex]Li^{+2}[/tex] ion is - 19.611 joules
The lowest possible energy, in Joules, for the electron in the [tex]Li^{2+}[/tex] ion is equal to [tex]1.96\times 10^{-17}\; Joules[/tex]
To determine the lowest possible energy, in Joules, for the electron in the [tex]Li^{2+}[/tex] ion, we would use the Bohr model:
Mathematically, Bohr's model is given by the equation:
[tex]Energy = -Z^2 \frac{k}{n^2}[/tex]
Where:
Z is the atomic number of an atom.n is the number of energy level.k is Rydberg constant.We know that the atomic number of lithium (Li) is equal to 3.
Also, at the lowest possible energy, n = 1.
Rydberg constant = [tex]2.179 \times 10^{-18}[/tex]
Substituting the parameters into the equation, we have;
[tex]E_1 = -3^2 \times \frac{2.179 \times 10^{-18}}{1^2} \\\\E_1 =9 \times 2.179 \times 10^{-18}\\\\E_1 =1.96\times 10^{-17}\; Joules[/tex]
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Write the electron configuration for the element titanium, TiTi. Express your answer in order of increasing orbital energy as a string without blank space between orbitals. For example, the electron configuration of LiLi could be entered as 1s^22s^1 or [He]2s^1.
Answer:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d² or [Ar] 3d² 4s²
Explanation:
Electron configuration can basically be referred to as the location of electron; how the electrons are arranged in the orbitals of the atoms.
Following Aufbau principle, electrons are arranged in the following order of orbitals.
1s 2s 2p 3s 3p 4s 3d and so on.
The s can hold a maximum of 2 electrons, p can hold a maximum of 6 electrons and d can hold a maximum of 10 electrons.
Titanium has an atomic number of 22. So the arrangement is given as;
Ti = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d²
The short hand notation is given as;
[Ar] 3d² 4s²
The electron configuration of Ti is
[tex]Ti: 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{2}[/tex] or [tex]Ti: [Ar] 4s^{2} 3d^{2}[/tex]
The electron configuration of an element is the distribution of electrons in atomic orbitals.
According to Aufbau's principle, the orbitals with lower energies are filled before the orbitals with higher energies.
We can know this order, using the diagonal rule (attached image).
The maximum number of electrons in each sublevel is:
s = 2p = 6d = 10f = 14Considering all these facts, and that Titanium has 22 electrons, the electron configuration of Ti is:
[tex]Ti: 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{2}[/tex]
Since [tex]1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6}[/tex] is the electron configuration of Argon, this can also be written as:
[tex]Ti: [Ar] 4s^{2} 3d^{2}[/tex]
The electron configuration of Ti is
[tex]Ti: 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{2}[/tex] or [tex]Ti: [Ar] 4s^{2} 3d^{2}[/tex]
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Given a fixed amount of gas help at a constant pressure, calculate the temperature to which the gas would have to be changed if a 1.75 L sample at 23.0*C were to have a final volume of 3.50 L.
A. 46.0*C
B. 89.5*C
C. 169*C
D. 319*C
E. 592*C
Answer:
592 K or 319° C
Explanation:
From the statement of Charles law we know that the volume of a given mass of gas is directly proportional to its absolute temperature at constant pressure. Thus;
V1/T1= V2/T2
Initial volume V1 = 1.75 L
Initial temperature T1= 23.0 +273 = 296 K
Final volume V2= 3.50 L
Final temperature T2 = the unknown
T2= V2T1/V1= 3.50 × 296 / 1.75
T2 = 592 K or 319° C
For each of the processes, determine whether the entropy of the system is increasing or decreasing. The system is underlined.
1. a snowman melts on a spring day
2. a document goes through a paper shredder
3. a water bottle cools down in a refrigerator
4. silver tarnishes
5. dissolved sigar precipitates out of water to form rock candy
A. Entropy is increasing
B. Entropy is decreasing
Entropy is INCREASING when a snowman melts, a document goes through paper shredder, silver tarnishes, while it is DECREASING when dissolved sugar precipitates, water vapor forms droplets and water cools down.
Entropy can be defined as the degree of randomness or disorder of a particular system.
Entropy is equal to zero (0) for a perfectly ordered system.
Heat increases the entropy of the system because more energy excites the molecules and it increases the amount of random activity.
Moreover, the cooling decreases the entropy of the system because molecules are more ordered and it decreases the amount of random activity.
In conclusion, entropy is INCREASING when a snowman melts, a document goes through paper shredder, silver tarnishes, while it is DECREASING when dissolved sugar precipitates, water vapor forms water droplets and the water cools down.
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230g sample of a compound contains 136.6g carbon, 26.4g hydrogen, and 31.8g nitrogen. What is masspercentif oxygen
Answer:
15.3 %
Explanation:
Step 1: Given data
Mass of the sample (ms): 230 gMass of carbon (mC); 136.6 gMass of hydrogen (mH): 26.4 gMass of nitrogen (mN): 31.8 gStep 2: Calculate the mass of oxygen (mO)
The mass of the sample is equal to the sum of the masses of all the elements.
ms = mC + mH + mN + mO
mO = ms - mC - mH - mN
mO = 230 g - 136.6 g - 26.4 g - 31.8 g
mO = 35.2 g
Step 3: Calculate the mass percent of oxygen
%O = (mO / ms) × 100% = (35.2 g / 230 g) × 100% = 15.3 %
Identify the elements that have the following abbreviated electron configurations.
A) [Ne] 3s23p5.
B) [Ar] 4s23d7.
C) [Xe] 6s1.
Answer:
A) Chlorine (Cl)
B) Cobalt (Co)
C) Caesium (Cs)
Hope this helps.
The abbreviated electron configurations that was given in the question belongs to
Chlorine (Cl)
Cobalt (Co)
Caesium (Cs) respectively.
Electronic configurations can be regarded as the electronic structure, which is the way an electrons is arranged in energy levels towards an atomic nucleus.The electron configurations is very useful when describing the orbitals of an atom in its ground state.To calculate an electron configuration, we can put the periodic table into sections, and this section will represent the atomic orbitals which is the regions that house the electrons. Groups one of the period table and two belongs to s-block, group 3 through 12 belongs to the d-block, while 13 to 18 can be attributed to p-block ,The rows that is found at bottom are the f-blockTherefore, electron configurations explain orbitals of an atom when it is in it's ground state.
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Given the initial rate data for the reaction being A + B + C --> D determine the rate expression for the reaction and the (k) rate constant. (The units of [A] [B] and [C] are all moles/liter and the units of IRR is moles/liter seconds). If the [A]=[B]=[C]=.30M, what would the IRR be? [A] [B] [C] IRR 0.20 0.10 0.40 .20 0.40 0.20 0.20 1.60 0.20 0.10 0.20 .20 0.20 0.20 0.20 .80
Answer:
k = 100 mol⁻² L² s⁻¹, r= k[A][B]²
Explanation:
A + B + C --> D
[A] [B] [C] IRR
0.20 0.10 0.40 .20
0.40 0.20 0.20 1.60
0.20 0.10 0.20 .20
0.20 0.20 0.20 .80
Comparing the third and fourth reaction, the concentrations of A and C are constant. Doubling the concentration of B causes a change in the rate of the reaction by a factor of 4.
This means the rate of reaction is second order with respect to B.
Comparing reactions 2 and 3, the concentrations of B and C are constant. Halving the concentration of A causes a change in the rate of the reaction by a factor of 2.
This means the rate of reaction is first order with respect to A.
Comparing reactions 1 and 3, the concentrations of A and B are constant. Halving the concentration of A causes no change in the rate of the reaction.
This means the rate of reaction is zero order with respect to C.
The rate expression for this reaction is given as;
r = k [A]¹[B]²[C]⁰
r= k[A][B]²
In order to obtain the value of the rate constant, let's work with the first reaction.
r = 0.20
[A] = 0.20 [B] = 0.10
k = r / [A][B]²
k = 0.20 / (0.20)(0.10)²
k = 100 mol⁻² L² s⁻¹
Please help me out ASAP!
What is meant by concentration?
Answer:
concentration is the abundance of a constituent divided by the total volume of a mixture.
Balance the following
Na+02-→ Na20
Al+O2 ->Al2O3
H2+12+ ->HI
Mg+H2O → Mg(OH)2+H2
Ca+O2 -> Cao
Answer:
1. Na + O2 → Na2O (Balanced)
2. 4Al + 3O2 → 2(Al2O3) (Balanced)
3. H2 + i2 → 2HI (Balanced)
4. Mg + 2H2O → Mg(OH)2+ H2 (Balanced)
5. 2Ca +O2 → 2CaO (Balanced)
Which is most likely to happen during a precipitation reaction?
A. A solid substance will break down into two new substances that
are gases.
B. An insoluble solid will form when ions in dissolved compounds
switch places.
C. A substance will react with oxygen to form water and carbon
dioxide.
D. A gas will form when positive ions switch places to form new
compounds.
Answer:
I think its B
Explanation:
Precipitation reactions leave a solid behind. The solid is called a precipitate.
Answer:
B
Explanation:
An insoluble solid will form when ions in dissolved compounds switch places.
2
22. A sodium chloride solution is 15.0% m/m%. Calculate mass of sodium chloride in 219 g solution.
14.2g
80.38
11.2 g
32.9 g
Answer: The mass of sodium chloride in 219 g solution is 32.9 g
Explanation:
To calculate the mass percent of element in a given compound, we use the formula:
[tex]\text{Mass percent of A}=\frac{\text{Mass of A}}{\text{mass of A +mass of B}}\times 100[/tex]
To find mass of sodium chloride in solution:
[tex]\text{Mass percent of sodium chloride}=\frac{\text{Mass of sodium chloride}}{\text{mass of solution}}\times 100[/tex]
Mass percent of sodium chloride= 15.0 %
Mass of solution = 219g
[tex]15=\frac{\text{Mass of sodium chloride}}{219}\times 100[/tex]
[tex]{\text{Mass of sodium chloride}=32.9g[/tex]
Thus mass of sodium chloride in 219 g solution is 32.9 g
The accepted value of the number of Liters of gas in a mole is 22.4. List two possible reasons on why our experiment yielded a different value for the number of Liters in a mole of a gas.
Hint: Our experiment was conducted in July, in St. Paul, Minnesota.
Answer:
- Pressure in St. Paul, Minnesota
- Temperature in St. Paul, Minnesota
Explanation:
22.4 L or dm³ is the volume for a gas under Standard pressure and temperature conditions.
It is logically to say, that tempereature value at the day of the experiment was not 273.15 K, which is 32°F
We can say, that the pressure was not 1 atm. St Paul Minnesota has a minimum, but a little height, so the pressure differs by few figures from the standard pressure values.
We also have to mention, that 22.4 L is the value for the Ideal gases at standards conditions. Ideal gases does not exisist on practice, we always talk about real gases. Don't forget the Ideal Gases Law equation:
P . V = n . R . T
Pressure . Volume = number of moles . 0.082 L.atm /mol. K . 273.15K
Number of moles must be 1 at STP, to determine a volume of 22.4L
If the equilibrium constant of the reaction is 0.85, then which statement is true if the mass of A is 10.5 grams; the density of B is 0.82 g/ml; the concentration of C is 0.64 M; and the concentration of D is 0.38 M.
A(s) + 3 B(l) _____ 2(aq) + D(aq)
Pick the correct statement about this system.
A. Q < K and reaction shifts left
B. Q > K and reaction shifts left
C. Q > K and reaction shifts right
D. Q = K and reaction does not shift
E. Q < K and reaction shifts right
Answer:
E. Q < K and reaction shifts right
Explanation:
Step 1: Write the balanced equation
A(s) + 3 B(l) ⇄ 2(aq) + D(aq)
Step 2: Calculate the reaction quotient (Q)
The reaction quotient, as the equilibrium constant (K), only includes aqueous and gaseous species.
Q = [C]² × [D]
Q = 0.64² × 0.38
Q = 0.15
Step 3: Compare Q with K and determine in which direction will shift the reaction
Since Q < K, the reaction will shift to the right to attain the equilibrium.
The initial concentrations of I2 and I− in the reaction below are each 0.0401 M. If the initial concentration of I−3 is 0.0 M and the equilibrium constant is Kc=0.25 under certain conditions, what is the equilibrium concentration (in molarity) of I−? I−3(aq)↽−−⇀I2(aq)+I−(aq)
Answer:
[I⁻] = 0.0352M
Explanation:
Based on the equilibrium:
I₃⁻(aq) ⇄ I₂(aq) + I⁻(aq)
Kc is defined as:
Kc = 0.25 = [I₂] [I⁻] / [I₃⁻]
The system reaches the equilbrium when the ratio [I₂] [I⁻] / [I₃⁻] is equal to 0.25
In the beginning, you add 0.0401M of both [I₂] [I⁻]. When the reaction reach the equilibrium, xM of both [I₂] [I⁻] is consumed producing xM of [I₃⁻]. That is written as:
[I₃⁻] = X
[I₂] = 0.0401M - X
[I⁻] = 0.0401M - X
X is known as reaction coordinate.
Replacing in Kc:
0.25 = [I₂] [I⁻] / [I₃⁻]
0.25 = [0.0401M - X] [0.0401M - X] / [X]
0.25X = 0.00160801 - 0.0802X + X²
0 = 0.00160801 - 0.3302X + X²
Solving for X:
X = 0.0049M → Right solution
X = 0.3252M → False solution. Produce negative concentrations
Replacing, equilibrium concentrations will be:
[I₃⁻] = X
[I₂] = 0.0401M - X
[I⁻] = 0.0401M - X
[I₃⁻] = 0.0049M
[I₂] = 0.0352M
[I⁻] = 0.0352M
The equilibrium concentration (in molarity) of [I⁻] should be considered as the 0.0352M.
Calculation of the equilibrium concentration:Since
I₃⁻(aq) ⇄ I₂(aq) + I⁻(aq)
Here Kc should be defined
Kc = 0.25 = [I₂] [I⁻] / [I₃⁻]
Also, The system finished the equilibrium at the time when the ratio [I₂] [I⁻] / [I₃⁻] is equivalent to 0.25.
Also,
[I₃⁻] = X
[I₂] = 0.0401M - X
[I⁻] = 0.0401M - X
Also,
0.25 = [I₂] [I⁻] / [I₃⁻]
0.25 = [0.0401M - X] [0.0401M - X] / [X]
0.25X = 0.00160801 - 0.0802X + X²
0 = 0.00160801 - 0.3302X + X²
Now
X = 0.0049M → Right solution
X = 0.3252M → False solution
Now equilibrium concentrations will be:
[I₃⁻] = X
[I₂] = 0.0401M - X
[I⁻] = 0.0401M - X
[I₃⁻] = 0.0049M
[I₂] = 0.0352M
[I⁻] = 0.0352M
Hence, The equilibrium concentration (in molarity) of [I⁻] should be considered as the 0.0352M.
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