Answer:
Q = -33.6kcal .
Explanation:
Hello there!
In this case, according to the equation for the calculation of the total heat of reaction when a fixed mass of a fuel like ethane is burnt, we can write:
[tex]Q=n*\Delta _cH[/tex]
Whereas n stands for the moles and the other term for the enthalpy of combustion. Thus, for the required total heat of reaction, we first compute the moles of ethane in 3 g as shown below:
[tex]n=3g*\frac{1mol}{30.08g}=0.1mol[/tex]
Next, we understand that -337.0kcal is the heat released by the combustion of 1 mole of ethane, therefore, to compute Q, we proceed as follows:
[tex]Q=0.1mol*-337.0\frac{kcal}{mol}\\\\Q=-33.6kcal[/tex]
Best regards!
What is 2AI(s) + FeO3(s) = Ai2O3(s) + 2Fe(s)
Answer:
it's a double displacement Reaction.
Calculate the pH of a solution with [H+] =1x10^-5
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Answer: 5
Explanation:
I hope this helped!
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In Which State of matter are molecules moving the slowest
A. Solid
B. Liquid
C. Gas
Answer:
Solid
Explanation:
Molecules in solids only vibrate in place, while the other two have moving molecules
Boyle's Law states that when a sample of gas is compressed at a constant temperature, the pressure P and volume V satisfy the equation PV = C, where C is a constant. Suppose that at a certain instant the volume is 300 cm3, the pressure is 180 kPa, and the pressure is increasing at a rate of 30 kPa/min. At what rate is the volume decreasing at this instant?
Answer:
The gas is decreasing at a rate of 50 cubic centimeters per minute.
Explanation:
The Boyle's Law is represented by the following expression:
[tex]P\cdot V = k[/tex] (1)
Where:
[tex]P[/tex] - Pressure, in kilopascals.
[tex]V[/tex] - Volume, in cubic centimeters.
[tex]k[/tex] - Proportionality constant, in kilopascal-cubic centimeters.
By definitions of rate of change and implicit differentiation, we derive the following differential equation:
[tex]\dot P \cdot V + P\cdot \dot V = 0[/tex] (2)
Where:
[tex]\dot P[/tex] - Rate of change of the pressure, in kilopascals per minute.
[tex]\dot V[/tex] - Rate of change of the volume, in cubic centimeters per minute.
Then, we clear the rate of change of the volume within (2):
[tex]P\cdot \dot V = -\dot P\cdot V[/tex]
[tex]\dot V = -\left(\frac{\dot P}{P} \right) \cdot V[/tex]
If we know that [tex]P = 180\,kPa[/tex], [tex]\dot P = 30\,\frac{kPa}{min}[/tex] and [tex]V = 300\,cm^{3}[/tex], then the rate of change of the volume is:
[tex]\dot V = -\left(\frac{\dot P}{P} \right) \cdot V[/tex]
[tex]\dot V = -50\,\frac{cm^{3}}{min}[/tex]
The gas is decreasing at a rate of 50 cubic centimeters per minute.
Calculate the pH of a 4.988 M solution of ascorbic acid, which has a ka of 8.0 x 10-5.
Report your answer with two decimal places. Example: 6.99
Answer:
pH= 1.70
Explanation:
I 4.988 0 0
C -x +x +x
E 4.988 -x x x
8.0 x 10^-5 = X^2/ 4.988 - x
(since the X value is so small, round 4.988-x to 4.988 because X is close to zero)
8.0 x 10^-5 = x^2/4.988
x4.988 x4.988
4.0 x 10^-4 = x^2
x = .0199
pH=-log[.0199] = 1.70
How many fluorine atoms are there in 39.4 moles of CF4?
Answer:
here
Explanation:
Answer: 4
A molecule of carbon tetrafluoride, CF4 , is made up of 1 carbon atom bonded to 4 fluorine atoms. Each carbon atom weighs 12.0 amu and each fluorine atom weighs 19.0 amu so 1 CF4 molecule weighs 1×12.0 amu + 4×19.0 amu = 88.0 amu. This number, 88.0, is called the molecular weight (or molecular mass) of CF4.
is sublimation exothermic or endothermic
Answer:
endormic
Explanation:
It occurs at a temperature and pressures below a substance's triple point on its phase diagram, which corresponds to the lowest pressure at which the substance can exist as a liquid
Help bestie pls help ASAP thank you
Explanation:
heyyyyyyyyy how are you sure
Write a structural formula for each of the following: (a) 3-Methylcyclobutene (b) 1-Methylcyclopentene (c) 2,3-Dimethyl-2-pentene (d) (Z)-3-Hexene (e) (E)-2-Pentene (f) 3,3,3-Tribromopropene (g) (Z,4R)-4-Methyl-2-hexene (h) (E,4S )-4-Chloro-2-pentene (i) (Z)-1-Cyclopropyl-1-pentene (j) 5-Cyclobutyl-1-pentene (k) (R)-4-Chloro-2-pentyne (l) (E)-4-Methylhex-4-en-1-yne
Answer:
Attached below
Explanation:
(a) 3-Methylcyclobutene
(b) 1-Methylcyclopentene
(c) 2,3-Dimethyl-2-pentene
(d) (Z)-3-Hexene
(e) (E)-2-Pentene
(f) 3,3,3-Tribromopropene
(g) (Z,4R)-4-Methyl-2-hexene
(h) (E,4S )-4-Chloro-2-pentene
(i) (Z)-1-Cyclopropyl-1-pentene
(j) 5-Cyclobutyl-1-pentene
(k) (R)-4-Chloro-2-pentyne
(l) (E)-4-Methylhex-4-en-1-yne
The structural formula of a compound ( chemical ) is the representation of the molecular structure of the compounds ( i.e. it shows how the atoms in the compound is arranged, also the chemical bonding within the molecules are represented as well.
Select the description of a galvanic (voltaic) cell. An electrochemical cell that uses electricity to produce an oxidation-reduction reaction. An electrochemical cell that produces electricity from a spontaneous oxidation-reduction reaction. One-half of an electrochemical cell in which either oxidation or reduction occurs. Connects the two half-cells in an electrochemical cell to maintain electrical neutrality.
Answer: An electrochemical cell that produces electricity from a spontaneous oxidation-reduction reaction
Explanation:
Galvanic cell is a device which is used for the conversion of the chemical energy produced in a redox reaction into the electrical energy.
Galvanic cell consists of two half cells known as anode and cathode. Oxidation takes place at anode and reduction takes place at cathode. The two half cells are connected by a salt bridge which contains an electrolyte which maintains the electrical neutrality.
Consider a free lysine amino acid in a solution buffered to pH = 9.00. What will be the overall charge on the residue?
Is it -2, -1, 0, 1, 2?
Answer:
Explanation:
+1
The overall charge on the residue ( lysine residue ) is ; ( C ) 0 charge
The a-aminium group of lysine amino acid will begin deprotonating by the presence of NaOH as the pH level of the solution increases.
Given that the pKa level of a-aminium group = 9. when the pH of the solution is buffered to 9.0 . half of the a-aminium ions that is present in the lysine amino acid will deprotonate leaving the overall charge on the lysine residue at neutral ( 0 charge ).
Hence we can conclude that the overall charge on the residue is a 0 charge.
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When sodium hydroxide NaOH dissociates in water, the oxygen atoms on the hydroxide anions will interact with:
Answer:
Hydroxide ions ( OH−) are negatively charged, and the formal negative charge is on the oxygen atom. Since opposite charges attract, the oxygen atoms will interact with the positive end of water's dipole.
Explanation:
Look at the H-R diagram. Which area of the diagram represents the white dwarfs? Give answer like top, right corner.
Answer:
I did this TGA got it right it is bottom left corner
Explanation:
If 0.000066 moles of 0.01 M solution of carbonic acid dissociates, then what is Ka of carbonic acid
Answer: 4.4 x 10^-7
Explanation:
0.000066 x 0.0000066 / 0.01
= 4.4 x 10^-7
Why does an asteroid get hotter when it goes close to the sun?
what is another name for horse
Answer:
Mount, Charger, Colt, Pony, and Folt
Explanation:
Answer:
A stallion or a mare
Explanation:
10) 81 grams of Au is how many mL ?
Answer: Thus 81 grams of Au is 9210 ml
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
[tex]\text{moles of Au}=\frac{81g}{196.96g/mol}=0.411moles[/tex]
1 mole of Au occupies = 22.4 L
Thus 0.411 moles of Au occupy = [tex]\frac{22.4}{1}\times 0.411=9.21L=9210ml[/tex]
81 grams of Au is 9210 ml
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2.0M Propionic Acid HC3H5O2 Dissolves In Distilled Water. If It Has A Ka Of 1.3*10-5, What Is The Final PH?
The base ethylamine C2H5NH2 has a Kb of 5.6*10-4. What will the pH be in .53 molar solution?
Answer: first you have to calculate the amount ionized. We will say it is x mol / L
then % ionization = (amount ionized / initial concentration) * 100%
x can be calculated using an ice chart
HC3H5O2 -----> H+ + C3H5O2-
Initial HC3H5O2 = 0.250
change = -x
equilibrium = 0.250 - x
initial H+ = 0
change = +x
equilibrium = x
C3H5O2- initial = 0
change = +x
equilibrium = x
Ka = [H=][C3H5O2-] / HC3H5O2]
1.3 * 10 ^ -5 = [x][x] / (0.250 - x)
So 1.3 * 10 ^ -5 * (0.250 - x) = x ^ 2
3.25 * 10^ -6 - (1.3 * 10^-5)x = x^2 now this is a quadratic equation and you have to rearrange it and solve for x
x^2 + 1.3 * 10^-5)x - 3.25 * 10^ -6 = 0
use the equation x = {-b (+ or -)[b^2 - 4.a.c] ^ 1/2} / 2a
you should get x = 1.80 * 10 ^ -3 or x = -1.80* 10^-3
but x can not be negative..
so x = 1.80 * 10 ^ -3
so percent ionization = (1.80 * 10 ^ -3 / 0.250) * 100%
=0.72 %
the other way which is more easier is
assuming that x is very small and therefore 0.250 - x is approximately equals to 0.250
then 1.3 * 10^-5 = x^2 / 0.250
so x^2 = 1.3 * 10^-5 * 0.250
x = 1.80 * 10 ^-3
then percent ionization is = (1.80 * 10 ^ -3 / 0.250) * 100%
=0.72 %
if the percent ionization is > 5 % you can not do that approximation. in such a case you have to solve the quadratic equation. that is why I showed both methods.
now you can do the parts b and c
b answer : percent ionization = 1.27 %
c answer : 2.54%
good luck
help with my science about the human body
Answer:
am sorry what exactly is your question?
GROUP NUMBER
ELEMENT
Potassium
Fluorine
Silicon
Radon
Gold
Beryllium
Oxygen
Neon
Rubidium
Tungsten
Arsenic
Calcium
Sodium
Aluminum
Chromium
Iodine
Helium
Nitrogen
Iron
Zinc
Answer:
Jet ğıpep2pep2p2pp3oroe88r82
How many grams are in 1.2 x 1024 atoms of sodium?
Answer:
46 g
Explanation:
First we convert 1.2 x 10²⁴ atoms of sodium into moles, using Avogadro's number:
1.2x10²⁴ atoms ÷ 6.023x10²³ atoms/mol = 2.0 molThen we convert 2.0 moles of sodium into grams, using sodium's molar mass:
2.0 mol Na * 23 g/mol = 46 gThus, there are 46 grams in 1.2x10²⁴ atoms of sodium.
I don’t understand please help
If anyone could help I’d appreciate it
Answer: 2.00 mol
Explanation:
The balanced chemical equation is:
[tex]2H_2(g)+O_2(g)\rightarrow 2H_2O(g)[/tex]
According to stoichiometry :
2.00 moles of [tex]H_2[/tex] require = 1.00 moles of [tex]O_2[/tex]
Thus 2.00 moles of [tex]H_2[/tex] will require=[tex]\frac{1}{2}\times 2.00=1.00moles[/tex] of [tex]O_2[/tex]
Thus both will act as limiting reagents and will be fully consumed.
2.00 moles of [tex]H_2[/tex] will form = 2 moles of [tex]H_2O[/tex]
Thus 2.00 moles of [tex]H_2[/tex] will form = [tex]\frac{2}{2}\times 2.00=2.00moles[/tex] of [tex]H_2O[/tex]
Thus 2.00 moles of [tex]H_2O[/tex] will be produced from the given masses of both reactants.
Is the Swedish timber industry more likely a result of good resource availability or a lack of trees elsewhere on Earth?
Answer:
The forest products industry plays a major role in the Swedish economy, and accounts for between nine and 12 percent of Swedish industry's total employment, exports, sales and added value. It includes companies within the pulp and paper industry, as well as the wood-mechanical industry.
__C+_SO2—_CS2 + __CO
Answer:
_c+_so2-_cs2+_co= Toxic
which element is shown in the picture here?
Aspirin synthesis involves the addition of an acetyl group to salicylic acid in a condensation reaction with an alcohol. The acetyl group could be added with a carboxylic acid but the preferred procedure is to use the acid anhydride. Why is preferable to use an acid anhydride for ester formation with an alcohol rather than a carboxylic acid
Answer:
See explanation
Explanation:
The synthesis of asprin involves the;
i) Hydrolysis of Methyl salicylate
ii) Reaction of salicylic acid with acid anhydride
The chemical name of asprin is acetylsalicylic acid.
It is preferable to use an acid anhydride for ester formation with an alcohol rather than a carboxylic acid because we will not produce water which can then cause the hydrolysis of the newly formed ester.
If 6.70 g of zinc is reacted with 27.5 g of silver nitrate, the products will be zinc nitrate and silver metal. What is the theoretical mass of silver that will be produced?
a. Write a balanced equation
b. Interpret the equation by
particles and by moles
c. What is the limiting reactant?
Given:
Molar mass AgNO3 =
Needed:
unknown:
available:
d. What is the theoretical mass of silver that will be produced?
e. If the actual yield of silver was 14.1 g, what is the percent yield of the
reaction?
Explanation:
a. Write a balanced equation
The balanced equation for the reaction is given as;
Zn + AgNO3 → Ag + ZnNO3
b. Interpret the equation by particles and by moles
In this equation, 1mol of Zn reacts with 1 mol of AgNO3 to from 1 mol of Ag and 1 mol of ZnNO3
1 mol = 6.022 * 10^23 particles
c. What is the limiting reactant?
The mol ratio between both reactants is 1 : 1 from the equation.
Converting the masses given to ml;
Number of mol = Mass / Molar mass
Zn;
Number of mol = 6.70 / 65.38 = 0.1025 mol
AgNO3;
Number of mol = 27.5 / 169.87 = 0.1619 mol
The limiting reactant in this reaction is Zn. This is because Zn would get used up before AgNO3 according to the number of moles calculated.
d. What is the theoretical mass of silver that will be produced?
1 mol of Zn produces 1 mol of Ag
0.1025 mol of Zn would also produce 0.1025 mol mol of Ag
Mass = Molar mass * Number of Moles = 107.87 * 0.1025
Mass = 11.05 g
e. If the actual yield of silver was 14.1 g, what is the percent yield of the
reaction?
Percent yield = Actual Yield / Theoretical yield * 100%
Percent yield = 11.05 / 14.1 * 100 = 78.36%
Ethanol (C2H5OH) is produced from the fermentation of sucrose in the presence of enzymes.
C12H22O11(aq) + H2O(g) 4 C2H5OH(l) + 4 CO2(g)
Determine the theoretical yield and the percent yields of ethanol if 665 g sucrose undergoes fermentation and 305.0 g ethanol is obtained.
theoretical
actual yield of ethanol = 305.0g
molar mass of sucrose = 342g
molar mass of ethanol =46g
mass of sucrose = 665g
mole of sucrose = mass / molar mass = 665/342
mole of sucrose =1.9 mole
sucrose : C2H5OH
1 : 4
1.9 : 1.9x4 =7.6 mole of C2H5OH are formed
mass (therotical yield ) of C2H5OH= mole x mass
mass (therotical yield ) of C2H5OH= 7.6 x 46 = 349.6g
percent yields of ethanol = actual /therotical x100
=305/349.6x100 = 87.24 %