Answer:
[tex]-277.6\ \text{kJ/mol}[/tex]
Explanation:
Heat of combustion of [tex]C_2H_5OH(l)[/tex] = -1366.8 kJ/mol
Heat of formation of [tex]CO_2(g)[/tex] = -393.5 kJ/mol
Heat of formation of [tex]H_2O(l)[/tex] = -285.8 kJ/mol
The reaction is
[tex]C_2H_5OH(l)\rightarrow 2CO_2(g)+3H_2O(l)[/tex]
Assuming [tex]x[/tex] is the standard enthalpy of formation of ethanol
[tex]-1366.8=2\times (-393.5)+3\times (-285.8)-x\\\Rightarrow x=2\times (-393.5)+3\times (-285.8)+1366.8\\\Rightarrow x=-277.6\ \text{kJ/mol}[/tex]
The standard enthalpy of formation of ethanol is [tex]-277.6\ \text{kJ/mol}[/tex].
The standard enthalpy of formation of ethanol is -277.6 kJ/mol.
The equation of the reaction is;
C2H5OH(l) + 3O2(g)⟶ 2CO2(g) + 3H2O(l)
The heat of combustion of each specie is listed below;
C2H5OH(l) = -1366.8 JK/mol
CO2(g) = -393.5 kJ/mol
H2O(l) = -285.8 KJ/ mol
Standard heat of formation of ethanol;
-1366.8 = 2( -393.5) + 3( -285.8 ) - x
where x = heat of formation
x = 2( -393.5) + 3( -285.8 ) + 1366.8
x = -277.6 kJ/mol
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How many molecules are in 45.0 grams of NaCl
Answer:
3.5*10^23
Explanation:
divide 45/molar mass
then multiple the answer to Avogadro's number
Answer:
10/13 × 6.022×10²³
Explanation:
ans: given mass / molar mass = number of moles
(M ).
number of moles(M) = number of molecules / avagadro number ...
=molar mass of NaCl = 58.5 gram
45/58.5 × 6.022 ×10²³
= 10/13 × 6.022 × 10²³ is the required number
HELP ME ASAP
Samantha and Claire determined the mass and volume of a piece of metal to be 24.16 g and 3.22 mL respectively. Determine the density of the metal.
Answer:
7.5031055900621
Explanation:
D= M/V
What classifies something as a chemical reaction?
Answer:
changes that change the matter of the object and made it into another object
Explanation:
Atoms are indivisible spheres.
Answer:
urm is that an answer lol
PLEASE HELP
WILL GIVE BRAINLIEST
If 175.0g of nitrogen is reacted with 250.0g of hydrogen, what is the theoretical yield of the reaction? What is the excess reactant? What is the limiting reactant? Show your work.
Answer:
Nitrogen gas is the limiting reactant
Hydrogen gas is the excess reactant
The theoretical yield is 425 g of ammonia
Explanation:
Equation of reaction: 3H2 + N2 ---> 2NH3
From the equation of reaction, 3 moles of hydrogen gas reacts with 1 mole of nitrogen to produce 2 moles of ammonia gas.
Molar mass of hydrogen gas = 2.0 g
Molar mass of nitrogen gas = 14.0 g
Molar mass of ammonia gas = 17.0 g
Number of moles of hydrogen gas in 250 g = 250/2 = 125 moles
Number of moles of nitrogen gas in 175 g = 175/14 = 12.5 moles
Mole ratio of Hydrogen to Oxygen = 125/12.5 = 10 : 1
Therefore, nitrogen gas is the limiting reactant.
Hydrogen gas is the excess reactant
14 g of nitrogen gas produces 17 × 2 g of ammonia = 34 g of ammonia
175 g will produce (34 × 175)/14 = 425 g of ammonia
Therefore the theoretical yield is 425 g of ammonia
Which group in the periodic table is known as the as the noble gases?
I don’t understand what I am supposed to do with this
DESPERATE WILL GIVE BRAINLIST AND THANKS
The half-life of an element is 150 years. If a 40-gram sample was originally deposited, how much is left
after 300 years?
Question 4 options:
30 grams
20 grams
10 grams
5 grams
Answer:
20 grams
Explanation:
40g= 300
x = 150
cross multiply, 40*150/300
6000/300= 20g
Which of the following would most likely make up a team of scientists?
OA. Younger people from educated families
B. People with the same perspectives but from different
backgrounds
OC. People with different experiences and backgrounds
OD. Older men with similar opinions
Answer:
I would go with C
Explanation:
Because if in a group of scientists, the people that are educated with different experiences will be helpful to invent a new thing by giving their own ideas and mixing them.
Hope i got to be Helpful!
How many moles of no are produced from a reaction if it’s mass is 2.05
Answer:
6.83 × 10^–2 mol NO
Explanation:
The number of moles of nitric oxide NO produced from a reaction if its mass is 2.05 is equal to 0.0683 mol.
What is a mole?A mole is represented by the symbol mol and can be defined as a scientific unit that is used to measure the amount of the substance. The substance can commonly be chemical entities but they are individually distinct.
A mole of the substance can be used to evaluate a large number of constituent particles. The amount of substance can be measured in terms of chemical entities of a substance in a sample.
The number of elementary units in 1 mole of a substance is equal to 6.023×10²³ which is called Avogadro’s constant.
Given, the mass of the Nitric oxide, NO = 2.05 g
The mass of one mole of Nitric oxide, NO = 30 g
We can calculate moles of the substance as, n = Mass/molar mass
Then, the number of moles of Nitric oxide, NO = 2.05/30 = 0.0683 mol
Therefore, the number of moles of Nitric oxide, NO is 0.0683 mol.
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someone help me with this rly quick
105006hm/ds to. m/s
convert and show the works
Answer:
10500600m/s
1ds=100m/s
2. After class, Claudia had a snack. Then, she drove home and settled down to relax, surrounded by candlelight. What types of combustion do Claudia’s various activities represent?
Answer:
The types of combustion are;
1) Claudia eating snack is slow combustion
2) Claudia driving home involves explosive combustion
3) The lit candle is a form of rapid combustion
Explanation:
Combustion is the rapid exothermic chemical reaction between a fuel and an oxygen source to produce oxidized compounds formed from the elements in the compounds present in the fuel, which when combined together in a mixture are known as smoke
The types of combustion are;
1) Digestion of the snack is the slow combustion of glucose
2) Combustion in the engine of the car is a form of explosive combustion
3) The burning of the candle is a form of rapid combustion
what would be the theoretical yield of 2SO2 + O2 + 2H2O --> 2H2SO4
Answer:
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Explanation:
Which option identifies why Tony does NOT purchase the strawberries in the following scenario?
Tony checks the Country of Origin label before purchasing organic strawberries and decides against buying them when he sees they
came from Chile.
He is not sure the strawberries are organically grown
O He does not believe the strawberries are fresh.
He only purchases strawberries grown locally
He is not sure of the strawberries' nutritional content
Answer:
He only purchases strawberries grown locally.
Explanation:
Based on the information we are given, this is the only reasonable answer.
Answer :He only purchases strawberries grown locally.
Explanation: The correct answer is He only purchases strawberries grown locally. Many consumers have preferences as to where their food comes from. Some want to avoid products that have been shipped extensively and prefer to purchase locally produced goods and services. Country of Origin labeling does not indicate whether a product is organic, its nutritional content, or whether it is fresh, and a consumer would need to determine this information another way.
The volume of water in a graduated cylinder was increased from 52.0 mL to 75.5 mL when a piece of irregular metal was placed in the water. If the piece of metal has a mass of 265.6 g, what is the density of the metal?
Answer:
11.30 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
volume = final volume of water - initial volume of water
volume = 75.5 - 52 = 23.5
From the question we have
[tex]density = \frac{265.6}{23.5} \\ = 11.302127...[/tex]
We have the final answer as
11.30 g/mLHope this helps you
Answer:
Approximately 11.3 g/mL
Explanation:
The formula for density is mass divided by density. In this problem, the mass is already given: 265.6 grams. The density is the part with the milliliters. 75.5 mL - 52.0 mL is 23.5 mL.
After plugging these numbers into the formula, you get 265.6 g/23.5 mL. After divided those numbers, you get 11.30212..... g/mL, which rounds to 11.30 g/mL.
I hope this helps!
How would one make a 2 M solution of a compound?
O A. By dissolving 1 molar mass of the compound in 2L of water
OB. By dissolving 2 moles of the compound in 1 L of water
Oc. By dissolving 2 g of the compound in 1 L of water
D. By dissolving 1 mole of the compound in 2 L of water
Answer:
B. By dissolving 2 moles of the compound in 1 L of water.
Answer:
b
Explanation:
a pe x :)
Radiation _____.
Occurs is solids.
Occurs in liquids.
Requires physical contact between molecules
Is the method of heat transfer used by the sun
Answer:
Option (d) is the correct answer.
Explanation:
Radiation is defined as electromagnetic energy that travels in space in the form of waves or particles. This means that heat energy will always travel from a warmer object to a colder object. For example, radiations coming from the Sun are able to transfer heat energy to the substance on which they fall. Thus, we can conclude that radiation is the method of heat transfer used by the Sun.
If the half-life of an element is 150 years, how much of a 400 gram sample would remain in 750 years?
Answer:
y
Explanation:
if something weighs 66 pounds on earth how much does it weigh on the moon
Answer:
about 12 pounds
Explanation:
Answer:
10.91 pounds
Explanation:
That is because an object or person on the moon would weigh 16.5% its weight on earth.
Mohs hardness strontium
Answer: 5.5
Explanation: Strontium titanate is both much denser (specific gravity 4.88 for natural, 5.13 for synthetic) and much softer (Mohs hardness 5.5 for synthetic, 6–6.5 for natural) than diamond.
What causes objects to speed up, slow down, and change directions?
4. milk turning sour
Is the change physical or chemical?
Why do you thinks so? (2-3 reasons/indicators)
Answer:
Chemical change
Explanation:
Hi again. The lactose in the milk is converted to lactic acid by microbes. It has turned into a new substance that is irreversable.
Which model is based on Bohr's quantum model?
Model A
Model B
Model C
Model D
Answer:
Model D
Explanation:
Bohr's Model has a planetary look. Where the electrons are in an orbit.
Answer:
The answer is model D
23) Assuming STP, how many moles are in 30 L SO2?
Answer:
1.34 moles SO₂(g)
Explanation:
At STP 1 mole of any gas occupies 22.4 Liters. So, for 30 Liters ...
moles SO₂(g) = 30L/22.4L·mol⁻¹ = 1.34 moles SO₂(g)
Both the nucleus and the vacuole have membranes that isolate the material inside them from the rest of the cell. Which of the following best describes why both organelles have membranes?
A.
The nucleus protects food, and the vacuole protects cytoplasm.
B.
The nucleus protects genetic material, and the vacuole protects food.
C.
The nucleus and the vacuole both protect genetic material.
D.
The nucleus protects water, and the vacuole protects waste.
Answer:
B
Explanation:
a speed-time graph which the displayed data forms a straight line is a example of?
Answer:
constant speed or a horizontal line is an rest
Explanation:
A student has 0.75 L of a 5.0 M solution and dilutes it to make 3.5 liters. What’s the molarity of the diluted solution?
1.1 M
2.0 M
1.6 M
.93 M
The molarity of the diluted solution : 1.1 M
Further explanationDilution is the process of adding solvent to get a more dilute solution.
The moles(n) before and after dilution are the same.
Can be formulated :
[tex]\tt n_1=n_2\\\\M_1.V_1=M_2.V_2[/tex]
M₁ = Molarity of the solution before dilution
V₁ = volume of the solution before dilution
M₂ = Molarity of the solution after dilution
V₂ = Molarity volume of the solution after dilution
M₁=5
V₁=0.75
V₂=3.5
[tex]\tt M_2=\dfrac{M_1.V_1}{V_2}\\\\M_2=\dfrac{5\times 0.75}{3.5}\\\\M_2=1.07\approx 1.1[/tex]
When 33 g of CaO and 10 g of H2O react, how many grams of calcium hydroxide would you expect to be produced* Explain your answer.
Answer:
Calculate the number of moles of oxygen required to react exactly with 4.30 ... How many moles of NH3 can be made from 2.00 moles of Nz if you have excess Hz? ... 10. How many grams of water are made when 3.00 moles of butanol is combusted? ... If 50.0 g of calcium oxide were produced, how many grams of calcium ...
Answer:
41.44 g
Explanation:
First of all, we must put down the equation of the reaction;
[tex]CaO + H2O ----->Ca(OH)2[/tex]
Number of moles of CaO = 33g/56 g/mol = 0.59 moles
Number of moles of H20 = 10g/18 g/mol = 0.56 moles
Since the reaction is in 1:1 mole ration, H2O is the limiting reactant
Hence;
mass of Ca(OH)2 produced = 0.56 moles * 74 g/mol = 41.44 g
what contribution to atomic theory resulted from albert einstein’s work?
Answer:
Albert Einstein is perhaps most famous for introducing the world to the equation E=mc2. In essence, he discovered that energy and mass are interchangeable, setting the stage for nuclear power—and atomic weapons. His part in the drama of nuclear war may have ended there if not for a simple refrigerator.
Explanation:
Albert Einstein is perhaps most famous for introducing the world to the equation E=mc2. In essence, he discovered that energy and mass are interchangeable, setting the stage for nuclear power—and atomic weapons. His part in the drama of nuclear war may have ended there if not for a simple refrigerator.
The contribution to atomic theory resulting from Albert Einstein's work is A new understanding that the nucleus contains protons and neutrons.
Albert Einstein's work contributed to the development of the theory of relativity, which had profound implications for our understanding of the structure of atoms. Through his work, it became clear that the nucleus of an atom contains positively charged protons and electrically neutral neutrons. This understanding of the composition of the atomic nucleus was a significant advancement in atomic theory.
While Albert Einstein made significant contributions to physics and our understanding of the universe, the specific discoveries mentioned in the other answer choices were made by other scientists and not directly attributed to Einstein.
Hence, the correct option is option b.
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Genesis lays an object on the table in a well-lighted room the object absorbs all visible light waves what color object does genesis see?
Answer:
The object Genesis sees is black.
Explanation:
The color an object reflects represents what the object's color is. For example, if a block reflects blue light, then only blue light is sent to our eyes, and hence we see the block as blue.
If an object absorbs all visible light waves, then, that means there's no visible light reflected, and we cannot see any color the object has. Hence, it is black in our eyes.
Hope this helped!