Answer:
Explanation:
An endothermic reaction is one in which heat is absorbed from the surroundings. The reaction vessel typically feels cold to the touch in the case of an endothermic reaction
An exothermic reaction is one in which heat is released into the surroundings. The reaction vessel typically feels hot in this case.
A cold pack uses the principle of an endothermic reaction. In this case, the cold pack works by cooling the injury through the endothermic reaction mechanism.
A hot pack works the other way round. It releases heat to the injury and makes it heated up through the principle of exothermic reaction
Rutherford used a beam of alpha particles for his scattering experiment what is the de Broglie wavelength of an alpha particle moving at a velocity of 2.15×10^7 m per second
The wavelength of an electron moving with a velocity of 2.05×10^7 ms^−1 is 3.55×10^−11 m.
What is de Broglie wavelength ?
In accordance with wave-particle duality, all quantum mechanical objects exhibit the De Broglie wavelength, which establishes the probability density of discovering the object at a specific location in the configuration space.
The de-Broglie equation can be used to determine an electron's wavelength.
λ= h/mv
= 6.626×10^−34 Js / 9.11×10 ^−31 kg×2.05×10^7 m/s
=3.55×10^−11 m
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Question:
Calculate the wavelength of an electron moving with a velocity of 2.05×10^7 ms^−1.
Which of the following is an incorrect representation for a neutral atom?
36Li
613C
3063Cu
1530P
This representation suggests that the element is phosphorus (P) with a mass number of 30, which is incorrect. The correct mass number for phosphorus is approximately 30.97. The incorrect representation for a neutral atom is 36Li
To determine the correct representation for a neutral atom, we need to consider the atomic number (Z) and mass number (A) of the element. The atomic number represents the number of protons in the nucleus, while the mass number represents the sum of protons and neutrons.
Let's analyze the given representations:
36Li:
This representation suggests that the element is lithium (Li) with a mass number of 36, which is incorrect. The correct mass number for lithium is approximately 6.94.
613C:
This representation suggests that the element is carbon (C) with a mass number of 13, which is correct. Carbon has different isotopes, and 13C represents one of its stable isotopes.
3063Cu:
This representation suggests that the element is copper (Cu) with a mass number of 63, which is correct. Copper has different isotopes, and 63Cu represents one of its stable isotopes.
1530P:
This representation suggests that the element is phosphorus (P) with a mass number of 30, which is incorrect. The correct mass number for phosphorus is approximately 30.97.
Therefore, the incorrect representation for a neutral atom is 36Li, as it does not match the known properties of lithium.
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Since benzoin and meso-hydrobenzoin have similar melting points, how would you confirm that the product you obtained from this reaction is indeed meso-hydrobenzoin using only melting point techniques? describe briefly how you would carry out this experiment.
The products benzoin and meso-hydro benzoin melting points are same. Their temperature is 13341 degrees Celsius. Using the melting point method makes it challenging to directly determine. It would be necessary to determine the reaction's end product and then measure the melting point.
What does the melting point experiment aim to achieve?The thermal analysis that is most usually used to describe solid crystalline materials is melting point determination. It is used to identify solid crystalline chemicals and to assess their purity in research and development as well as in quality control in different industry areas.
The melting values of the products were between benzoin and meso-hydro benzoin 135 and 137, indicating that the molecule is likely benzoin because they are so similar to benzoin's melting points (135 to 137). Compared to hydroxybenzoic acid, benzoin has a melting point range that is closer to the finished product.
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Question 6 of 10
>
At 25 °C, what is the hydroxide ion concentration, [OH-], in an aqueous solution with a hydrogen ion concentration of
[H"]=1.7 x 10-6 M?
[OH-] =
The hydroxide ion concentration, [OH-] : 6.31 x 10⁻⁹ M
Further explanationpH=- log [H⁺]
pH+pOH= 14
A hydrogen ion concentration of [H"]=1.7 x 10⁻⁶ M
\(\tt pH=-log[1.7\times 10^{-6}]\\\\pH=6-log~1.7\\\\pH=5.8\)
\(\tt 5.8+pOH=14\\\\pOH=8.2\\\\ (OH^-)=10^{-8.2}=6.31\times 10^{-9}\)
help pls!!!!!!!!!!!!!
Answer:
1. C + O₂ → CO₂
2. C + CO₂ → 2 CO
3. Fe₂O₃ + 3 CO → 2 Fe + 3 CO₂
A pure substance does not conduct electricity in the solid state but it does dissolve in water and the resulting solution conducts electricity. The substance has a fairly high
melting point. The substance is most likely to be what type of compound?
An ionic compound
A crystalline compound
A covalent compound
A metallic compound
Match each agent of mechanical weathering to its picture.
Freezing and Thawing
Animal Actions
Plant Growth
Abrasion
Release of Pressure
Water, ice, acids, salts, plants, animals, and temperature fluctuations are all mechanical weathering agents. Erosion is the process by which the broken pieces of rock and mineral are moved away after a rock has been cracked.
Is mechanical weathering influenced by freezing and thawing?Rocks that have holes or are porous (have holes) experience freeze-thaw weathering (allows water to pass through). In this case, mechanical weathering is evident. Different fissures in the rock allow water to enter (from rain, melting snow, or ice).
What is weathering with pressure release?Weathering that releases pressure. Definition. expansion associated with the release of confining pressure when deeply buried rock is unroofed, leading to the development of fractures near the surface of solid rock. Typically, fractures spread along surfaces parallel to and near the surface.
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What is the total number of Ions in N2O3?
N2O3 has a total of eight lone pairs of electrons. In chemistry, a lone pair is an unshared pair or a non-bonding pair of valence electrons that are not shared with another atom in a covalent connection.
What is lons pair?A lone pair, also known as an unshared pair or a non-bonding pair, is an unshared pair of valence electrons that are not shared with another atom in a covalent connection in chemistry. Atoms' outermost electron shell contains lone pairs. The Lewis structure can be used to locate them.A lone pair of electrons is an electron pair that is not shared by any of the participating atoms. Atoms' outermost electron shell contains lone pairs. One nitrogen atom, three hydrogen atoms, and one lone pair on the nitrogen atom make up three bond pairs in the ammonia molecule, for instance.To learn more about lons pair refer to:
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PLEASE HELP!
The vapor pressure of benzene at 25 °C is 95.1 mm Hg and of toluene 28.4 mm Hg. The mass fractions of benzene and toluene in a solution are 0.5.
a) Calculate the partial pressure of benzene and toluene above the solution.
b) Calculate the total vapor pressure above the solution.
c) Calculate the vapor composition above the solution.
Benzene be B
Toluene be T
We have made then one lettered to make things easier
\(\sf P^0_B=95.1mmHg,P^0_T=28.4mmHg\)\(\sf x_B=x_T=0.5\)\(\\ \rm\Rrightarrow \dfrac{P^0_B-P_B}{P^0_B}=x_B\)
\(\\ \rm\Rrightarrow 95.1-P_B=95.(0.5)\)
\(\\ \rm\Rrightarrow 95.1-P_B=47.55\)
\(\\ \rm\Rrightarrow P_B=47.55mmHg\)
And
\(\\ \rm\Rrightarrow \dfrac{P^0_T-P_T}{P^0_T}=x_T\)
\(\\ \rm\Rrightarrow 28.4-P_T=28.4(0.5)\)
\(\\ \rm\Rrightarrow P_T=14.2mmHg\)
Total vapour pressure
28.4+95.1123.6mmHgWhat is the setup to which you compare all the others in an experiment?
Answer:
A part of the experiment that is not being tested and is used for comparison of the experimental results. A control group should be used when conducting an experiment. This group receives the same attention as the test groups, however, it will not be influenced by the variable the other groups are testing.
Explanation:
도움이 되기를 바랍니다.... 안전을 유지하세요 ✨
I don’t wanna fail if you know the answer pls help me :(
Answer:
Liquid to gas.
Explanation:
Answer:
b
Explanation:
Water in to a gas or evaporation
what is the difference between sea and ocean
The Sea and the ocean are just different terms that mean same thing
Answer:
Explanation:
In terms of geography, seas are smaller than oceans and are usually located where the land and ocean meet. Typically, seas are partially enclosed by land. Seas are found on the margins of the ocean and are partially enclosed by land. ... Seas are smaller than oceans and are usually located where the land and ocean meet.
what is the formula for selenium tetrafluoride
Answer:
SeF4
Explanation:
SeF4
Answer:
The anwser is SeF4
Which of the following statements are true concerning the results of the Human Genome Project? Check all that apply.
Researchers now have maps of every human’s genome.
The Human Genome Project has raised many complicated ethical issues.
All medical conditions can be attributed to a specific gene.
Researchers now have a map of an “average” human genome.
The following statement is true concerning the results of the Human Genome Project:
The Human Genome Project has raised many complicated ethical issues.
What is Human Genome?
The human genome refers to the complete set of genetic information (DNA) present in human cells. It includes both the protein-coding and non-coding regions of DNA. The human genome is made up of about 3 billion base pairs and is organized into 23 pairs of chromosomes. The study of the human genome is an important field of genetics and has many implications for understanding human biology, evolution, and disease.
The Human Genome Project was a scientific research project that aimed to identify and map all the genes in the human genome, which contains all the genetic information needed for human development and function. The project was completed in 2003 and provided a wealth of information about the structure and function of the human genome, including the location and sequence of all human genes.
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How many moles are in 88 g of propaņe, C3H8.
Answer:
2 MOLES
Explanation:
FIRSTLY CALCULATE GMM OF PROPANE WHICH IS
(12)*3 + 1*8 = 44 GM
THEN, MOLES= GIVEN MASS/44
WHICH IS 88/44=2 MOLES
10 kg of Phenanthrene is to be burnt with supplied air which is 30% less than the requirement. Find the exit gas stream average molecular weight and the leftover Phenanthrene amount in the reactor.
The exit gas stream has an average molecular weight of 29.0 g/mol and the amount of leftover Phenanthrene in the reactor is 5377 g.
How to calculate exit gas and leftover?Start by calculating the stoichiometric amount of air required to burn 10 kg of Phenanthrene. The balanced chemical equation for the combustion of Phenanthrene is:
C₁₄H₁₀ + 19O₂ → 14CO2 + 5H₂O
Therefore, to burn 10 kg (10000 g) of Phenanthrene:
nO₂ = 19 x (10000 g / 178.24 g/mol) = 1065.5 mol
So the actual amount of oxygen supplied will be:
nO₂, supplied = 0.7 x nO₂ = 745.9 mol
The amount of air required to supply this much oxygen can be calculated using the ideal gas law:
PV = nRT
where P = pressure, V = volume, n = number of moles, R = gas constant, and T = temperature.
Assuming standard temperature and pressure (STP):
P = 1 atm = 101.3 kPa
T = 273 K
R = 8.314 J/mol.K
The volume of air required is then:
Vair = nair × RT/P = (nO₂,supplied + nN₂,supplied) × RT/P
where nN₂,supplied = number of moles of nitrogen in the supplied air.
Since air is about 79% nitrogen by volume, assume that the number of moles of nitrogen is proportional to the number of moles of oxygen:
nN₂,supplied = (0.79/0.21) x nO₂,supplied = 2807.2 mol
Therefore,
Vair = (nO₂,supplied + nN₂,supplied) × RT/P
= (745.9 + 2807.2) × 8.314 × 273 / 101.3
= 63106 L
Calculate the average molecular weight of the exit gas stream using the ideal gas law again:
n = PV/RT
where n = number of moles of gas, P = pressure, V = volume, R = gas constant, and T = temperature.
Assuming that the combustion products are at the same temperature and pressure as the supplied air (STP):
nCO₂ = nH₂O = nO₂,supplied = 745.9 mol
nN₂ = nN₂,supplied = 2807.2 mol
The total number of moles of gas in the exit stream is then:
ntotal = nCO₂ + nH₂O + nN₂ = 745.9 + 745.9 + 2807.2 = 4298.0 mol
The volume of the exit stream can be calculated using the ideal gas law:
Vexit = ntotal × RT/P = 4298.0 × 8.314 × 273 / 101.3 = 36534 L
The average molecular weight of the exit gas stream is then:
M = mtotal/ntotal
where mtotal = total mass of gas in the exit stream.
Calculate mtotal by adding up the mass of each component in the exit stream:
mtotal = mCO₂ + mH₂O + mN₂
where mCO₂, mH₂O, and mN₂ = masses of carbon dioxide, water vapor, and nitrogen, respectively.
Calculate these masses using the molecular weights of the compounds and the number of moles:
mCO₂ = nCO₂ × MCO₂ = 745.9 × 44.01 g/mol = 32804 g
mH₂O = nH₂O × MH₂O = 745.9 × 18.02 g/mol = 13419 g
mN₂ = nN₂ × MN₂ = 2807.2 × 28.01 g/mol = 78617 g
Therefore,
mtotal = mCO₂ + mH₂O + mN₂ = 32804 + 13419 + 78617 = 124840 g
Substituting into the equation:
M = mtotal/ntotal = 124840 g/4298.0 mol = 29.0 g/mol
So the exit gas stream has an average molecular weight of 29.0 g/mol.
The leftover Phenanthrene amount can be calculated as follows:
mPhenanthrene,leftover = mPhenanthrene,initial - mCO₂ - mH₂O
where mPhenanthrene,initial = initial mass of Phenanthrene, which is 10 kg (10000 g).
Substitute these values into the equation:
mPhenanthrene,leftover = 10000 - 32804 - 13419 = 5377 g
Therefore, the amount of leftover Phenanthrene in the reactor is 5377 g.
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The Sun has been shining on this swimming pool all day. The water is much warmer than it was in the morning. Describe what is happening to the water in terms of temperature, particle speed, and kinetic energy.
Answer:
The waters' temp increased
Explanation:
The temperature of the water in the swimming pool has increased due to the heat from the Sun. As a result, the particles in the water are moving faster and have a higher kinetic energy than in the morning.
8. Jill conducted an experiment to investigate which plant food would make her
plants grow faster. She tried four different plant foods on plants of the same
type and age. Jill concluded that the plant that was fed Brand A grew the
fastest. Jill did not realize that the plant that was fed Brand A also received
more sunlight. (SC.7.N.1.5.3)
What error did Jill make in her experiment?
a) She used the wrong kind of plant.
b) She used too much plant food.
c) She did not control the variables.
6) Name the following compounds
a. S2Cl3
B.KNO3
C.NH4Br
The name of the three compounds are Disulfur Dichloride, Potassium nitrate and Ammonium bromide respectively.
What are the names of the given compounds?1. The name of the first compound is Disulfur Dichloride.
Disulfur Dichloride is a type of inorganic compound comprise of sulfur and chlorine. There are also many other names which we can be used like sulfur monochloride, disulphur dichloride and sulphur monochloride. It is used to show C-S bonds.
2. The name of the second compound is Potassium nitrate.
Potassium nitrate is a compound that belong to the alkali metal nitrate. Potassium nitrate is also known as Indian saltpetre. The potassium nitrate is present in the nature but in the form of mineral. The potassium nitrate is used for making the explosives, matches, rocket fuel and fireworks.
3.The name of the third compound is Ammonium bromide.
Ammonium bromide is a type of compound that contains ammonium salt of hydrobromic acid. It can melt easy on providing heat. It is also soluble in water. It gives yellow colour. Ammonium bromide is the weak acid.
So we can conclude that the name of the three compounds are Disulfur Dichloride, Potassium nitrate and Ammonium bromide respectively.
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A tree burns down and forms ashes
Physical or
Chemical
Answer:
It is a chemical change.
Explanation:
A tree burning down would be a chemical change because the composition of the tree is what changes, not just the physical characteristics.
describe ways to seperate heterogeneous mixtures
Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H2SO4(aq) → Al2(SO4)3(s) + 3H2( g) If, in a laboratory experiment, 19.0 g of aluminum reacts with excess sulfuric acid, and 51.1 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?
The percentage yield of Al₂(SO₄)₃ is 89.7114 if 19.0 g of aluminium reacts with excess sulfuric acid, and 51.1 g of Al₂(SO₄)₃ are collected.
What is a combination reaction?A combination reaction is a reaction in which two reactants combine to form one product.
2Al + 3H₂SO₄ → Al₂(SO₄)₃ + 3H₂
from the equation of reaction, 2 moles of Al react to produce 1 mole of Al₂(SO₄)₃
2 moles of Al contains = (2 × 27) = 54g of Al
1 mole of Al₂(SO₄)₃ contains (1 × 342.15) = 342.15g of Al₂(SO₄)₃
54g of Al produces 342.15g of Al₂(SO₄)₃,
19.0 g of Al will produce x g of Al₂(SO₄)₃
Solve for x
X = (19.0 g × 342.15) ÷ 54
X = 120.386g
Theoretical yield of Al₂(SO₄)₃ = 120.386g
The percentage yield of a substance = (actual yield ÷ theoretical yield) × 100
Actual yield = 108g
Theoretical yield = 120.386g
% yield = (108 ÷ 120.386g) × 100
% yield = 89.7114
The percentage yield of Al₂(SO₄)₃ is 89.7114.
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PLEASE HELP...
Balance this nuclear reaction by supplying the missing nucleus. Replace each question mark with an appropriate integer or symbol.
Cf98249 + ? ⟶Db105260+410n
The balanced form of the nuclear equation is as follows; 249/98 Cf + 15/7 N⟶ 260/105 Db + 4(1/0) n.
What is a nuclear equation?A nuclear equation is process such as the fission of an atomic nucleus, or the fusion of one or more atomic nuclei and/or subatomic particles in which the number of protons and/or neutrons in a nucleus changes.
According to this question, Californium element is a reactant to produce dubnium and a neutron as products.
However, the law of conservation of mass must be fulfilled by ensuring the mass and atomic numbers of elements in reactant and product side are the same.
249/98 Cf + 15/7 N⟶ 260/105 Db + 4(1/0) n
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Explain two positive aspects of using methane recapture systems.
Answer:
Two positive aspects of using methane recapture systems are able to generate significant electricity. Another benefit is that the process of anaerobic digestion creates heat that can be used to warm buildings where animals are kept
Answer: The correct answer is;
Two positive aspects of using methane recapture systems include lowering the impact on greenhouse gasses and the production of energy. Methane is a very potent greenhouse gas that is contributing to global warming. As a result, the recapturing process reduces the methane impacts of global warming by reclaiming and reusing the gas for other purposes. Recaptured methane can be stored and used to generate electricity or used as fuel to power updated vehicles and other engines on the farm. The overall benefits from this combination are reducing impacts causing global warming and lower the cost of electricity or fuel on the farm.
Explanation: This answer has been confirmed correct.
Identify the type of reaction and predict the product: Calcium + water -->
Answer:
Exothermic Reaction
Product = Calcium hydroxide + hydrogen
Explanation:
advantages of rusting
Answer:
there are many advantages
Explanation:
Rust has a strong memory management system. It assigns each piece of memory to a single owner and determines who can access it. It also ensures parallelized code, enabling software to run safely on multiple processors. Rust is easier to maintain and debug.
hope it helps you
Determine the molecular formula of a compound that contains 26.7% P 12.1% N and 61.2% Cl and has a molar mass of 812 g/mol
Considering the definition of empirical and molecular formula, the molecular formula is P₇N₇O₁₄.
Empirical formulaThe empirical formula is the simplest expression to represent a chemical compound, which indicates the elements that are present and the minimum proportion in whole numbers that exist between its atoms, that is, the subscripts of chemical formulas are reduced to the most integers. small as possible.
Molecular formulaThe molecular formula is the chemical formula that indicates the number and type of different atoms present in the molecule. The molecular formula is the actual number of atoms that make up a molecule.
In other words, the molecular formula is the actual formula of the molecule and is made up of the symbols that represent the chemical elements and the subscripts that indicate the number of atoms of each element that participate in the formation of the molecule.
Molecular formula in this caseIn this case, you know:
P: 26.7 %N: 12.1 %Cl: 61.2 %Assuming a 100 grams sample, the percentages match the grams in the sample. So you have 26.7 grams of P, 12.1 grams of N and 61.2 grams of Cl.
Then it is possible to calculate the number of moles of each atom in the molecule, taking into account the corresponding molar mass:
P: \(\frac{26.7 g}{31\frac{g}{mol} }\)= 0.86 moles
N: \(\frac{12.1 g}{14\frac{g}{mol} }\)= 0.86 moles
O: \(\frac{61.2 g}{35.45\frac{g}{mol} }\)= 1.72 moles
The empirical formula must be expressed using whole number relationships, for this the numbers of moles are divided by the smallest result of those obtained. In this case:
P: \(\frac{0.86 moles}{0.86 moles }\)= 1
N: \(\frac{0.86 moles}{0.86 moles }\)= 1
O: \(\frac{1.72 moles}{0.86 mole}\)= 2
Therefore the P: N: O mole ratio is 1: 1: 2
Then, the empirical formula is P₁N₁O₂= PNO₂, with a empirical mass of 31 g/mol + 14 g/mol + 2× 35.45 g/mol= 115.9 g/mol
The molecular formula can be calculated as MF= n(EF)
where:
MF= molecular formulan=molecula mass÷ empirical massEF= empirical formulaIn this case, the value n can be calculated:
n= 812 g/mol÷ 115.9 g/mol
Solving:
n= 7
Then, the molecular formula can be calculated as MF= 7×EF
Finally, the molecular formula is P₇N₇O₁₄.
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2
You can find an explanation of what a graph's symbols
mean in the:
А A key
B
Data
C
X-axis
D
Y-axis
Answer:
The answer is A. Key
Explanation:
Identify the labeled structures,
A
B
C
D
E
A
Btw this is science so ye-
Answer:
A Golgi body
B vacuole
C mitochondrion
D nucleus
E cell membrane
How many moles of water are produced if 3.30 moles of N20 is
produced? NH4NO3 --> N20 + 2 H2O (mole to mole conversion) 1 step
Answer:
The netto reaction equation is:
2 OH- + 2H+ = 2 H2O
So the answer is 2 moles.