Answer:
The change in entropy is -1083.112 joules per kilogram-Kelvin.
Explanation:
If the water is cooled reversibly with no phase changes, then there is no entropy generation during the entire process. By the Second Law of Thermodynamics, we represent the change of entropy ([tex]s_{2} - s_{1}[/tex]), in joules per gram-Kelvin, by the following model:
[tex]s_{2} - s_{1} = \int\limits^{T_{2}}_{T_{1}} {\frac{dQ}{T} }[/tex]
[tex]s_{2} - s_{1} = m\cdot c_{w} \cdot \int\limits^{T_{2}}_{T_{1}} {\frac{dT}{T} }[/tex]
[tex]s_{2} - s_{1} = m\cdot c_{w} \cdot \ln \frac{T_{2}}{T_{1}}[/tex] (1)
Where:
[tex]m[/tex] - Mass, in kilograms.
[tex]c_{w}[/tex] - Specific heat of water, in joules per kilogram-Kelvin.
[tex]T_{1}[/tex], [tex]T_{2}[/tex] - Initial and final temperatures of water, in Kelvin.
If we know that [tex]m = 1\,kg[/tex], [tex]c_{w} = 4190\,\frac{J}{kg\cdot K}[/tex], [tex]T_{1} = 373.15\,K[/tex] and [tex]T_{2} = 288.15\,K[/tex], then the change in entropy for the entire process is:
[tex]s_{2} - s_{1} = (1\,kg) \cdot \left(4190\,\frac{J}{kg\cdot K} \right)\cdot \ln \frac{288.15\,K}{373.15\,K}[/tex]
[tex]s_{2} - s_{1} = -1083.112\,\frac{J}{kg\cdot K}[/tex]
The change in entropy is -1083.112 joules per kilogram-Kelvin.
Answer:
The change in entropy = [tex]-1083.534 J/k[/tex]Explanation:
Change in entropy,
[tex]\delta S = mCp * In[\frac{T2}{T1}][/tex]
The initial temperature,
[tex]T1 = 100^oC\\\\T1 = 100+273\\\\T1 = 373k[/tex]
Final value of temperature,
[tex]T2 = 15^oC\\\\T2 = 15+273\\\\T2 = 288k[/tex]
where,
[tex]m = 1kg\\\\Cp = 4190 J/kg.k[/tex]
Substitute into [tex]\delta S[/tex]
[tex]\delta S = mCp * In[\frac{T2}{T1}]\\\\\delta S = 1 * 4190 * In[\frac{288}{373}]\\\\\delta S = 4190 * In[0.7721]\\\\\delta S = 4190 * [-0.2586]\\\\\delta S = -1083.534 J/k[/tex]
The negative sign exists because the change in entropy will be decreasing due to cooling.
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Considering the side chain of each of the amino acids at pH 7.4, is that amino acid classified at neutral, basic, or acidic? You are currently in a sorting module. Turn off browse mode or quick nav, Tab to items, Space or Enter to pick up, Tab to move, Space or Enter to drop. Neutral Basic Acidic
Answer:
Considering the side chain of each of the amino acids at pH 7.4, is that amino acid classified at neutral, basic, or acidic? You are currently in a sorting module. Turn off browse mode or quick nav, Tab to items, Space or Enter to pick up, Tab to move, Space or Enter to drop. Neutral Basic Acidic
The answer is in the the images. I have placed all the structures in the specific boxes. I hope this helps.
How many ions are in 1
mole of potassium sulfate?
Answer:
We will need two potassium ions to balance the charge on the sulfate ion, so the proper chemical formula is K 2SO 4.
Explanation:
hope this helps
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When two nitrogen atoms combine, they form a
A) Compound
B) Liquid
C) mixture
D) Molecule
Answer:
I guess the answer is compound
Explanation:
Coz compound it is on there playing with me again Go ahead and paste it in the class
Qualitatively explain the effect of changing concentration of Cu2+ on voltage using your experimental observations and the Keq values below. (No calculations are required).
(a) Cu^2+(aq) + 4NH3(aq) ⇄ [Cu(NH^3)4]^2+(aq) Keq = 1.2 x 10^12
(b) CuS(s) ⇄ Cu^2+(aq) + S^2-(aq) , Keq = 8.5 x 10^-45
Cu/Zn = 0.525 V
after 1 drop NH3: 0.505 V
after 2 drops NH3: 0.435 V
Cu/Zn = 0.510 V
after 1 drop Na2S: 0.452 V
after 2 drops Na2S: 0.393 V
For the reaction 2Na + Cl2 2NaCl, calculate the percent yield if
155.0 g of chlorine (Cl2) should be produced and your experiment
produced 143 g (C12).
Answer:
[tex]Y=92.25\%[/tex]
Explanation:
Hello there!
In this case, according to the given chemical reaction, it is possible for us to calculate the percent yield by dividing the actual yield of 143 grams of gaseous chlorine by the theoretical yield of 155 g of this gas. In such a way, we proceed as follows:
[tex]Y=\frac{143g}{155g} *100\%[/tex]
Which has a result of:
[tex]Y=92.25\%[/tex]
Regards!
is a glow stick Endothermic or exothermic ?
Answer:
exothermic
Explanation:
Name the following alkene:
CH3CH = CHCH2CH3
A. 3-pentane
B. 2-pentene
C. 2-pentane
D. 3-pentene
Answer:
2-pentene
Explanation:
The name of the alkene is 2 pentene. The correct option is B, 2-pentene.
What is 2-pentene?Alkenes with the chemical formula [tex]C_5H_10[/tex] are known as pentene. Within its molecular structure, each has one double bond.
The given alkene [tex]CH_3CH = CHCH_2CH_3[/tex] is 2-pentene because the double bond is present in the second carbon and it's pentene because there are five carbons present.
Thus, the correct option is B. 2-pentene.
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identify two conjugate base for each compound HCN and HBr
The conjugate base of HCN is CN^-
The conjugate base of HBr is Br^-
how many cats are in the word
Answer: more than 70,00 and most of that population is living on the streets
How many neutrons are in an atom of argon–40?
Answer:
22 neutrons
Explanation:
If so please sorry
What happens when an electron moves to a higher energy level?
A. It releases energy of a specific frequency
B. It gains energy in a quantized amount.
C. It loses energy in the form of light.
D. It absorbs photons of many energies
ANSWER: B. It gains energy in a quantized amount.
Answer:
B. It gains energy in a quantized amount.
A substance in a specific state of matter with volume of 6 liters was transferred to a 12 liter container. The substance took up the
A. It is highly compressible.
B. It also has a definite shape.
C.Its particles slide past one another
D. Its intermolecular forces are of high strength.
[tex]\huge\color{yellow}\boxed{Answer:}[/tex]
My answer is C.Its particles slide past one another
[tex]\huge\color{yellow}\boxed{toshiro hitsugaya}[/tex]
When the 6 liters volume of the substance takes up 12 liter container, we conclude that the substace is highly compressible.
What is compressibility?
Compressibility is the measure of the relative volume change of a solid or a fluid with respect to pressure change.
Gases are the most compressible susbtance because most of the volume of a gas is composed of the large amounts of empty space between the gas particles.
Therefore, when the 6 liters volume of the substance takes up the entire volume of 12 liter container, we can conclude that the substace is highly compressible.
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A 2.5 M solution of a weak acid is prepared. Using a pH meter, the pH is measured to be 5.1. Calculate the acid ionization constant, [tex]K_{a}[/tex] , of this weak acid.
Show your work
Molarity of acid=2.5M
pH=5.1.
ka=?
Now
We need to write an eqn to show the dissociation of the acid
HA + H2O === H3O+ + A-
Writing The Equilibrium(Or Acid dissociation constant) of this reaction
Ka =[H3O+] {A-]/ {HA].
The concept behind this is
concentration of Products divided by those of reactants. Water is not written because its a pure liquid and does not affect the Equilibrium constant.
Now If you have any Idea on ICE tables..
You'd know that the concentration of acid will decrease by 2.5-x
Whilst the products...will increase by x each
Note: This is when the ratio of their Moles are in 1:1
ka= x.x/2.5-x
Since the Moles of A- and H3O+ are in 1:1... Their concentrations at equilibrium will be the same
so
Ka= x²/2.5-x
Now what is x??
x is the Hydrozonium ion concentration.
we can get it from the pH formula
pH= -log (H3O+)
Making H3O+ subject by applying Logarithm Rules
H3O+ = 10^-ph
x=10^-5.1
=7.94x10^-6.
Now back to Ka
Ka= x²/2.5-x
Ka= (7.94x10^-6)²/2.5-(7.94x10^-6)
Ka= (7.94x10^-6)²/2.4999
Ka= 2.52x10^-11.
Was a Fun One
The ionization constant of this weak acid is [tex]2.52*10^{-11}[/tex]. The values can be substituted in dissociation formula.
What information do we have?
Molarity of acid=2.5M
pH=5.1
To find:
ka=?
Calculation of ionization constant:[tex]HA + H_2O < === > H_3O^+ + A^-[/tex]
The value of dissociation constant will be:
[tex]Ka =[H_3O^+] [A^-]/ {HA][/tex]
The Moles of A- and H3O+ are in 1:1.Their concentrations at equilibrium will be the same.
[tex]Ka= x.x/2.5-x\\\\Ka= x^2/2.5-x\\\\pH= -log (H_3O^+)\\\\H_3O^+ = 10^{-pH}\\\\x=10^{-5.1}\\\\x=7.94*10^{-6}[/tex]
[tex]Ka= x^2/2.5-x\\\\Ka= (7.94*10^{-6})^2/2.5-(7.94*10^{-6})\\\\Ka= (7.94*10^{-6})^2/2.4999\\\\Ka= 2.52*10^{-11}\\\\[/tex]
Thus, ionization constant of this weak acid is [tex]2.52*10^{-11}[/tex].
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sodium is an inactive metal why
Answer:
Inactive metals are inert metals that doesn’t react with most of the chemicals.They are highly resistant to oxidation and corrosion when exposed to moisture.
Explanation:
If it takes 720. mL of 0.00125 M Mg(OH)2 to neutralize 425 mL of an HCI
solution, what is the concentration of the HCI? Mg(OH)2 + HCl →MgCl2
+ H20
Answer:
0.004235 M
Explanation:
The neutralization reaction of this question is given as follows:
Mg(OH)2 + 2HCl → MgCl2 + 2H2O
Using the formula below:
CaVa/CbVb = na/nb
Where;
Ca = concentration of acid (M)
Cb = concentration of base (M)
Va = volume of acid (mL)
Vb = volume of base (mL)
na = number of moles of acid = 2
nb = number of moles of base = 1
From the information provided in this question;
Ca = ?
Cb = 0.00125 M
Va = 425 mL
Vb = 720 mL
na (HCl) = 2
nb = (Mg(OH)2) = 1
Using the formula; CaVa/CbVb = na/nb
Ca × 425/0.00125 × 720 = 2/1
425Ca/0.9 = 2
472.2Ca = 2
Ca = 2/472.2
Ca = 0.004235 M
When a lead acid car battery is recharged by the alternator, it acts essentially as an electrolytic cell in which solid lead(II) sulfate PbSO4 is reduced to lead at the cathode and oxidized to solid lead(II) oxide PbO at the anode.Suppose a current of 62.0 is fed into a car battery for 23.0 seconds. Calculate the mass of lead deposited on the cathode of the battery. Round your answer to 3 significant digits. Also, be sure your answer contains a unit symbol.
Answer: The mass of lead deposited on the cathode of the battery is 1.523 g.
Explanation:
Given: Current = 62.0 A
Time = 23.0 sec
Formula used to calculate charge is as follows.
[tex]Q = I \times t[/tex]
where,
Q = charge
I = current
t = time
Substitute the values into above formula as follows.
[tex]Q = I \times t\\= 62.0 A \times 23.0 sec\\= 1426 C[/tex]
It is known that 1 mole of a substance tends to deposit a charge of 96500 C. Therefore, number of moles obtained by 1426 C of charge is as follows.
[tex]Moles = \frac{1426 C}{96500 C/mol}\\= 0.0147 mol[/tex]
The oxidation state of Pb in [tex]PbSO_{4}[/tex] is 2. So, moles deposited by Pb is as follows.
[tex]Moles of Pb = \frac{0.0147}{2}\\= 0.00735 mol[/tex]
It is known that molar mass of lead (Pb) is 207.2 g/mol. Now, mass of lead is calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\ 0.00735 = \frac{mass}{207.2 g/mol}\\mass = 1.523 g[/tex]
Thus, we can conclude that the mass of lead deposited on the cathode of the battery is 1.523 g.
Astronauts must be protected from extreme heat while
reentering the Earth's atmosphere. Scientists can use the
engineering design process to help make reentry safer.
You have defined the problem as a need for heat shields to be stronger. What
should be your next step in using the engineering design process to solve the
problem?
O A. Communicate your solution to your team members.
O B. Update your initial design for the heat shield.
O C. Identify the criteria and constraints of the project.
O D. Build a prototype of a possible new type of heat shield.
The next engineering step to be taken is to update your initial design for the heat shield.
What is a heat sheild?The term heat sheild refers to a device that can be used to shield an from astronaut extreme heat especially as they re-enter the earth's atmosphere.
After you have identified the problem, the next engineering step to be taken is to update your initial design for the heat shield.
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Which substance has Delta.Hf defined as 0 kJ/mol?
A. H2O (s)
B. Ne (l)
C. F2 (g)
D. CO2 (g)
Answer:
its actually c
Explanation:
Calculate the molar mass of Ca3(PO4)2
934.32 g Ca3(PO4)2 =______
moles Ca3(PO4)2
Answer:
Molar mass of Ca₃(PO₄)₂ = 310.18 g/mol934.32 g Ca₃(PO₄)₂ = 3.01 moles Ca₃(PO₄)₂Explanation:
The molar mass (MM) of Ca₃(PO₄)₂ can be calculated as follows:
MM of Ca₃(PO₄)₂ = (MM of Ca)*3 + [(MM of P) +(MM of O)*4]*2MM of Ca₃(PO₄)₂ = 310.18 g/molNow we can convert 934.32 g of Ca₃(PO₄)₂ into moles:
934.32 g ÷ 310.18 g/mol = 3.01 moles12 points
Methyl methacrylate has a molar mass of 100 g/mole When a sample of methyl methacrylate weighing 3.14 g was completely combusted, the only products formed
were 6.91 g of CO2 and 2.26 g of water. What is methyl methacrylate's molecular formula?
O A C5H8O2
OBC6H120
OCC7H16
OD. None of the above
O E C4H403
Answer:
C₅H₈O₂
Explanation:
methyl methacrylate = 100 amu
6.91g CO₂ = 0.157 moles
2.26g H₂O = 0.125 moles
0.157 ÷ 0.125 = 1.256
{(CO₂)₁.₂₅₆ + (H₂O)₁} × 4 = (CO₂)₅ + (H₂O)₄
C₅H₈O?
C₅ = 60.05 amu H₈ = 8.064 amu
60.05 + 8.064 = 68.114 amu
100 amu - 68.114 amu = 31.886 amu
O = 16 amu
O = 2
The molecular formula of methyl methacrylate is C₅H₈O₂. The correct option is A, C₅H₈O₂.
What is methyl methacrylate?
Methyl methacrylate (MMA) is a colorless liquid monomer with a distinctive fruity odor. It is an organic compound that belongs to the family of acrylic esters.
We have to determine the empirical formula of methyl methacrylate first and then multiply it by the integer n to determine the molecular formula. Empirical formula:
CO₂ and H₂O are the combustion products of methyl methacrylate.
C₅H₈O₂ + (9n / 2)
O₂ → 5CO₂ + (n)H₂O
There are 5 C atoms and (8 + 2n), H atoms in the left and 5 C atoms, and n H atoms in the right.
5C = 5C, and 8 + 2n = nH.
n = 6
Molecular formula calculation is dividing the molecular weight by the empirical formula weight to determine the multiplication factor.
C₅HₙO₂ (empirical formula) has a weight of:
(5 x 12.011) + (8 x 1.008) + (2 x 15.999) = 100.12 g/mol
The actual molecular weight of methyl methacrylate is 100 g/mol.
Therefore, the molecular formula is (C₅H₈O₂) x 1, which is C₅H₈O₂, option A.
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Questions
Determine the primary and secondary valencies of the following complexes and calculate their spin only magnetic
moment.
iii. [Cu(OH2)6]504
i. K[TI(CN).]
ii. [V(NH3)4Br2]
iv. K3 [Cr(CN)6]
Answer:
yes
Explanation:
yes
Select ALL of the abiotic factors
lesson 5.01
Question 1 options:
air
light
fungi
soil
salinity
Answer:
I think it should be
salinity and
light
which best describes the type of titration for the graph below? O strong acid titrated with a strong base
O strong base titrated with a strong acid
O weak acid titrated with a strong base
O weak base titrated with a strong acid
Answer:
B. strong base titration with a strong acid
what are factors that affecting the boiling point of liquid?
The compound AlP (aluminum phosphide) is a compound semiconductor having mixed ionic and covalent bonding. Calculate the fraction of bonding that is ionic.
Answer:
0.086
Explanation:
The formula for calculating the fraction of a covalent bond can be expressed as:
= exp (-0.25ΔE²)
[tex]= exp[-0.25(E_{Al}-E_{p})^2]---(1)[/tex]
from the equation above;
[tex]E_{Al}[/tex] = the electronegativity of aluminum
[tex]E_P[/tex] = electronegativity of phosphorus
Using the data from periodic table figures;
[tex]E_{Al}[/tex] = 1.5
[tex]E_P[/tex] = 2.1
∴
fraction of the covalent = exp[-0.25(1.5 - 2.1)²]
fraction of the covalent = exp(-0.09)
fraction of the covalent = 0.914
Now, the fraction of ionic bond will be = 1 - the fraction of covalent bond
= 1 - 0.914
∴
the fraction of bond that is ionic = 0.086
Carbon dioxide had how many nonbonding electron pairs in its electron arrangement?
A. 2
B. 4
C. 8
D. 6
E. 3
Answer: A.) 2 is the answer.
Explanation:
Pbo.....
= 2Pb +......
Answer:
It's
Explanation:
Pbo + c
= pb + co2
While balancing it becomes
2pbo + c = 2pb + co2
(I was also doing same qn)
What happens in radioactive decay?
O A. An electron is lost to form a negatively charged particle.
O B. An unstable nucleus breaks down into smaller parts.
O C. Two smaller nuclei are joined to form one larger nucleus.
O D. A large nucleus breaks apart to form smaller nuclei.
SHIRME
A radioactive atom will spontaneously release radiation in the shape of energy rather than particles in order to transition into a more steady state.
Why is something radioactive?Radioactivity, as its name suggests, seems to be the act of generating radiation without any external cause. This is carried out by an unstable atomic nucleus that "wants" to abandon certain power in order to change to a more stable form.
Are people radioactive at all?Absolutely, since humans consume radioactive materials from the environment through food, drink, and air, our bodies are inherently radioactive. Our bodies take these substances in and store them in our bones, tissues, and organs. We also breathe them in and consume them.
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A chemistry student needs 30.0 g of acetic acid for an experiment. He has available 1.2 kg of a 7.58% w/w solution of acetic acid in acetone.
Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button.
Round your answer to 3 significant digits.
Answer:
The mass of solution will be "395.78 g".
Explanation:
Given:
Mass of acetic acid,
= 30 g
Percentage,
= 7.58% w/w
Now,
⇒ % [tex]=\frac{Mass \ of \ acetic \ acid}{Mass \ of \ solution}\times 100[/tex]
By putting the values, we get
⇒ [tex]7.58=\frac{30}{Mass \ of \ solution}\times 100[/tex]
⇒ [tex]Mass \ of \ solution=\frac{30\times 100}{7.58}[/tex]
⇒ [tex]=\frac{3000}{7.58}[/tex]
⇒ [tex]=395.78 \ g[/tex]
What piece of apparatus could be used to measure the volume of gas produced in a reaction
1)beaker
2)gas syringe
3) top pan balance
Answer: 2)gas syringe
Explanation:
the volume of a gas is usually measured with a gas syringe (or sometimes with an upside-down measuring cylinder)
Answer:
top pan balance
Explanation: