When 3.93 grams of lactic acid, CHoOs(s), are burned in a bomb
calorimeter that has a total heat capacity of 10.80 kJ-K-1, the
temperature of the calorimeter increases by 5.43 K. Assume AHrxn
=
AErxn. Given that AH°f of H¿O(I) = -285.8 kJ-mol-1 and AH°f of CO:(g)
= -393.5 kJ• mol-1, calculate the AH°f of lactic acid.
Answers
The heat released in the combustion of lactic acid is absorbed by the
calorimeter and in the decomposition of the lactic acid.
ΔH°f of lactic acid is approximately -716.2 kJ
Reasons:
Known parameters are;
Mass of the lactic acid = 3.93 grams
Heat capacity of the bomb calorimeter = 10.80 kJ·K⁻¹
Change in temperature of the calorimeter, ΔT = 5.34 K
ΔHrxn = ΔErxn
ΔH°f of H₂O(l) = -285.8 kJ·mol⁻¹
ΔH°f of CO₂(g) = -393.5 kJ·mol⁻¹
The chemical equation for the reaction is presented as follows;
C₃H₆O₃ + 2O₂ → 3CO₂ + 3H₂OThe heat of the reaction = 10.80 kJ·K⁻¹ × 5.34 K = 57.672 kJ
Molar mass of C₃H₆O₃ = 90.07 g/mol
Number of moles of C₃H₆O₃ = [tex]\dfrac{3.93 \, g}{90.07 \, g/mol}[/tex] = 0.043633 moles
Number of moles of CO₂ produced = 3 × 0.043633 moles = 0.130899 moles
Heat produced = 0.130899 mole × -285.8 kJ·mol⁻¹ = -37.4109342 kJ
Moles of H₂O produced = 0.130899 moles
Heat produced = 0.130899 mole × -393.5 ≈ -51.51 kJ
Therefore, we have;
Heat absorbed by the lactic acid = ΔH°f of H₂O + ΔH°f of CO₂ + Heat absorbed by the calorimeter
Which gives;
Heat absorbed by lactic acid = -37.4109342 kJ - 51.51 kJ + 57.672 kJ ≈ -31.249 kJ
The heat absorbed by the lactic acid ≈ -31.249 kJ
[tex]\Delta H^{\circ}f \ of \ C_3H_6O_3 = \dfrac{-31.249}{0.043633} \approx -716.2[/tex]
ΔH°f of C₃H₆O₃ ≈ -716.2 kJ
Heat of formation of lactic acid ≈ -716.2 kJ.
Learn more here:
https://brainly.com/question/13185938
Related Questions
A sample of gas at 1.0°C is expanded at constant pressure from 10 L to 15 L. The final temperature is:
a: 1.50 °C
b: 411 °C
c: None of all
d:138 °C
e: 183 °C
Answers
Answer:
y
Explanation:
yea Mami you know like for real I feel you you know iam seeing but tomorrow I see the equation for the last works positive AAAAA
which of these elements has the greatest attraction for electrons in a covalent bond?
A. Se
B. As
C. Br
D. Kr
Answers
Answer:
C) Bromine
Explanation: Bromine needs just one electron to fill its outer shell.
Bromine has the greatest attraction for electrons in a covalent bond because it has the highest electronegativity among the given option as it needs only one electron to complete its octet. Therefore, option (C) is correct.
What are halogens?Halogens are the elements of group 7 of the modern periodic table, which contains five elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
Halogens are generally nonmetals in which fluorine and chlorine are gases at room temperature and bromine is a liquid, iodine and astatine are solids. Halogens are very reactive as they have seven valence electrons and need only one electron to get a noble gas configuration.
As we move left to right in a period the electronegativity increases and all the given elements Se, As, Br and Kr are elements of the same period but the Kr is a noble gas. Therefore, Bromine has the greatest attraction for electrons in a covalent bond.
Learn more about halogens, here:
brainly.com/question/11156152
#SPJ2
What energy keeps the water cycle going?
Answers
Answer:
the the that keeps the water cycle going is heat
Na is best known as a(n):
Answers
Answer:
sodium
Explanation:
sodium is an element with the atomic no. of 11 and atomic mass of approximately 23
How did max planck contribute to the modern atomic theory?
Answers
Answer:
Planck made many contributions to theoretical physics, but his fame rests primarily on his role as originator of the quantum theory. This theory revolutionized our understanding of atomic and subatomic processes, just as Albert Einstein's theory of relativity revolutionized our understanding of space and time
Answer:
revolutionized our understanding of atomic and subatomic processed
What is condensation
Answers
Condensation happens one of two ways: Either the air is cooled to its dew point or it becomes so saturated with water vapor that it cannot hold any more water.
Explain why the element of an atom doesn't change if you remove or add electrons or neutrons
Answers
Answer:
If you could miraculously remove two neutrons from an atom's nucleus, the atomic number and electrical charge would stay unaltered. Because neutrons have no electrical charge, adding or removing them from the nucleus has no effect on the nucleus's electrical charge. It does, however, alter the nucleus's mass. Isotopes are formed by adding or subtracting neutrons from the nucleus.
How many unpaired electrons does fluorine have in its ground state electron configuration?
Answers
Answer:
1 unpaired electron (s)
Explanation:
The ___ of a bottle tells you how much liquid it can hold. what is the anewer
Answers
Answer:
Volume
Explanation:
Volume is how much of a substance something can hold!
Hope this helped, have a nice day! :)
The word that completes the sentence is "volume."The volume of a bottle refers to how much liquid it can hold, typically measured in liters or milliliters.
Knowing the volume of a bottle is important when you need to measure out or store a certain amount of liquid. Different types of bottles have different capacities, so it's important to check the label or specifications to determine the right size for your needs.
Volume is a measure of three-dimensional space. It is often quantified numerically using SI derived units or by various imperial or US customary units (such as the gallon, quart, cubic inch). The definition of length (cubed) is interrelated with volume. The volume of a container is generally understood to be the capacity of the container; i.e., the amount of fluid (gas or liquid) that the container could hold, rather than the amount of space the container itself displaces.
Thus, the word that completes the sentence is "volume."
Learn more about volume,here:
https://brainly.com/question/28058531
#SPJ3
Scientific Notation!!!!!
#9 b) PLEASE HELP!!!
Answers
Explanation:
9) a) (9.84×10³)/(6.12×4.27×10³+⁷) = 9.84×10³/6.12×4.27×10¹⁰ = 9.84×10³-¹⁰/6.12×4.27
= 0.376×10^-7.
b) (4.36×10⁸×1.82×10³)/(0.0856×4.7×10⁶)
= (7.9352×10⁸+³)/(0.40232×10⁶)
= 19.72×10⁸+³-⁶ = 19.72×10⁵
hope this helps you.
Ribosome factory part or worker
Answers
Name the following compound and tell what type of compound it is: Protons 6, Neutrons 8, and electrons 6
Answers
Answer:
Carbon-14
Explanation:
It's carbon, because the element has 6 proton.
It's not an ion, because there are same number of proton and electron 6=6
It is carbon-14 because 6 proton + 8 neutron = 14
If the sample has a density of 2.71 g/cm3 , how many oxygen atoms does it contain?
Answers
Answer:
djxgfchkgvjhbkjlnk:Hg/ufy
Explanation:
fzdxgfchg,jv.hkbjnj.jhcgbc
In order for a light bulb to be turned on in a circuit, it must have what kind of switch?
Answers
Answer:
Both switches must be closed in order for the circuit to be complete and for the bulb to light. (This would indicate the 'armed' status of this burglar alarm.) Magnetic switches come in 2 varieties - "Normally Closed" and "Normally Open". These 2 terms describe the state of the switch when it is NOT being controlled by the magnet.
Explanation:
Acetylene (C2H2) gas and oxygen (02) gas react to form carbon dioxide (CO2) gas and water (H20) vapor. Suppose you have 2.0 mol of C,H, and 1.0 mol
of o, in a reactor
Calculate the largest amount of CO, that could be produced. Round your answer to the nearest 0.1 mol.
Answers
The largest amount of CO₂ produced when 2 moles of C₂H₂ reacted with 1 mole of O₂ is 0.8 mole
We'll begin by writing the balanced equation for the reaction. This is given below:
2C₂H₂ + 5O₂ —> 4CO₂ + 2H₂O
2 : 5
2 : 1
From the balanced equation above,
We can see that O₂ is the limiting reactant as lesser amount of it is available.
Finally, we shall determine the largest amount of CO₂ produced by using the limiting reactant as illustrated below:
From the balanced equation above,
5 moles of O₂ reacted to produce 4 moles of CO₂.
Therefore,
1 mole of O₂ will react to produce = 4/5 = 0.8 mole of CO₂.
Thus, the largest amount of CO₂ produced from the reaction is 0.8 mole
Learn more: https://brainly.com/question/25299182
What is the name of the ion with 4 neutrons and 4 electrons with a 1- charge?
A: Hydrogen
B: Berrylium
C: Lithium
D: Helium
Answers
Answer:
C.
Explanation:
I search it on Gøogle
You and your family have just arrived in Water Cycle Land. You are going on a new ride called the Water Cycle. You sit in your seat and the ride begins. All of a sudden something goes wrong. Your body is turning into a water droplet! Think about what you have learned about the water cycle. Now tell a story about what happens to you as you travel through the water cycle. By the way, how do you get your body back to normal?
Answers
Answer: you dont drink water for years
Explanation: dont drink water for years on end
Look at the numbered locations. Our solar system can be found at_____
Location 1
Location 2
Location 3
Location 4
Answers
Answer:
location 3...........
6. What is the atomic mass of Hafnium if out of every 200 atoms, 10 have mass 176.00 g/mol, 38 have mass
177.00 g/mol, 54 have mass 178.00 g/mol, 28 have mass 179.00 g/mol, and 70 have mass 180.00 g/mol?
Answers
Answer:
ttyhjj
Explanation:
The Lewis electron-dot structure of oxygen has how many dots?
Answers
Answer:
Oxygen has 6 valence electrons and follows the octet rule.
If you were drawing a lewis structure for O2, there would be a total of 12 valence electrons (6 x 2 = 12).
The completed structure would have a double bond between the two oxygen atoms with 2 lone pairs per oxygen, giving you a total of 8 electrons that are lone pairs (or dots).
The RDI for sodium for adults is 2300mg. What amount of table salt (in grams) contains this quantity of sodium? Express answer to two significant figures and include the appropriate units.
Answers
Answer:
hihihihhihihihihiihihihihiihihihih
5. A student measures the mass of an object three times on a balance in order to calculate the objects
density. The recorded masses are 70.21 g, 64.55 g, and 74.70 g. The accepted value for the mass of
the object is 70.21 g.
a. Are these measurements accurate? Why or why not?
b. Are the measurements precise? Why or why not?
Answers
Answer:
This is not chemistry this is physics
33) 1 e = ........С
O 1.6*10^-27
O * 1.6 *10^-19
O 1.66 * 10^-19
o 1.66* 10^-27
Answers
Answer
0.16574
Explanation:
because why not
helpppppppppppppppppppppppppppppppppp
Answers
Answer:
the drops of liquid are coming from the decreases. they are formed as the motion of the water particles in the air gas. this change in motion cause air in the air to change from a liquid to a water
Hello there!
The drops of liquid are coming from the air. They are formed as the motion of particles in the air decreases. This change in motion causes water in the air to change from a liquid to a gas.
Hope this helps you!
~Just a joyful teen
[tex]SilentNature :)[/tex]
✿❀❁❀✿An atom contains three protons, two neutrons, and one electron. What is the charge of the nucleus?
A: 3+
B: 5+
C: 2+
D: 0
Answers
Answer:
A.3+
Explanation:
️️️️️️️️️️️️️️
Why do you think dark surfaces absorb radiation better than light surfaces?
Answers
Your answer→ The lighter side absorbs less of the incident light, reflecting some of the energy. Darker materials also emit radiation more readily than light-colored materials, so they cool faster.
To solve this we must be knowing each and every concept related to radiation. Therefore, dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.
What is radiation?According to the energy of the emitted particles, radiation is frequently classified as being either ionizing or non-ionizing. More than 10 eV is often carried by ionizing radiation, which is sufficient to ionize atoms as well as molecules and rupture chemical bonds.
The word refers to radiation having an energy level high enough to ionize atoms, or to remove electrons from atoms to produce ions. Whenever an electron is removed from an atom's electron shell, or, as we may say, when it is "tried to knock out," the action of ionization takes place. Dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.
Therefore, dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.
To know more about radiation
https://brainly.com/question/13163856
#SPJ2
50 Points (Brainliest too)! Please help!
1. In detail, explain what transmutation is.
2. In one to two sentences, explain what an alpha particle is.
3. Explain the difference between a chemical equation and a nuclear equation.
4. What is the relationship between the atomic number and the mass number of a 5. nucleus?
Please help me understand these!! I'm really confused!
Answers
Answer:
Transmutation is the conversion of an atom of one element into an atom of a different element through nuclear changes.
An alpha particle is a particle composed of 2 protons and 3 neutrons. It results from transmutation because of the change in protons in a large nucleus.
A chemical equation is balanced accord to the number of atoms of each element before and after the change. This is also shows the Law of Conservation of Matter.
A nuclear equation is balanced according to mass number and charge (atomic number). These equations can’t be balanced like chemical equations because the identities of the atoms can change. On the left of equation, the top number is the atomic mass and the bottom number is the atomic number. Take note that if you add the atomic mass (top number), you’ll get the the atomic mass of of the atom pre-transmutation. Same applies with atomic number. This shows a balanced nuclear equation.
The atomic number is the number of protons in a nucleus. The mass number is the sum of the protons and neutrons in a nucleus. Electrons have very small masses, so they are not accounted in atomic mass.
The green light emitted by a stoplight has a wavelength of 505 nm. What is the frequency of this photon? (c = 3.00 × 10⁸ m/s).
Answers
Answer:
5.9405*10^14 Hz
Explanation:
Remember the equation c=v*λ
v=frequency
λ=wavelength
By manipulating the equation, we can get it in terms of frequency:
c/λ=v
Now convert wavelength to meters (1nm=m*10^-9)
5.05*10^-7m (2 decimal places were shifted to make the number between 1-10, hence the -7 exponent)
Use the manipulated equation:
(3.00*10^8)/(5.05*10^-7), which yields:
5.9405*10^14 Hz (or s^-1)
The frequency of the photon will be "[tex]5.9405\times 10^{14} \ Hz[/tex]".
According to the question,
Wavelength,
[tex]\lambda = 505 \ nm[/tex]or,
[tex]= 5.05\times 10^{-7} \ m[/tex]
As we know the equation,
→ [tex]c = v\times \lambda[/tex]
or,
→ [tex]v = \frac{c}{\lambda}[/tex]
By putting the values, we get
[tex]= \frac{3.00\times 10^8}{5.05\times 10^{-7}}[/tex]
[tex]= 5.9405\times 10^{14} \ Hz[/tex]
Thus the above answer is right.
Learn more:
https://brainly.com/question/14523087
How many moles are present in a sample of HCI with a mass of with a mass of 3.65g?
Answers
Answer:
number of moles = 0.1001 mol
Explanation:
number of moles = mass/molar mass
number of moles = 3.65g / 36.459 g/mol
n = 0.1001 mol
Colligative properties are dependent only on the number of particles in a solution, and not their identity. (select all that apply) Select one or more: a. Acidity b. Depression of freezing point c. Lowering of vapor pressure d. Osmotic pressure e. Elevation of boiling point f. Mortality g. Value h. Molarity
Answers
These colligative properties include reduced vapor pressure, increased boiling point, decreased freezing point, and increased osmotic pressure.
What do you mean by osmotic pressure?When a semipermeable membrane separates a solution from pure water, osmotic pressure is defined as the pressure that must be applied to the solution side to stop fluid movement.These colligative properties include reduced vapor pressure, increased boiling point, decreased freezing point, and increased osmotic pressure. As described in this module, this small set of properties is critical to many natural phenomena and technological applications.The pressure required to prevent water from diffusing through a membrane via osmosis is known as osmotic pressure. The concentration of the solute determines it. Water diffuses from the lower concentration area to the higher concentration area.Osmotic pressure is a 'colligative' property, like freezing point depression, which means that it depends on the number of particles in solution but not on their chemical identity.To learn more about : Osmotic pressure
Ref : https://brainly.com/question/14208018
#SPJ2