Among the compounds listed, CH4 has the highest vapor pressure, followed by CH3CH-CH3CH2CH3, CH3CH2CH2CH2CH3, and CH3CH2CH2OH.
The vapor pressure of a substance is determined by the strength of the intermolecular forces between its molecules. In general, the more volatile a substance is, the higher its vapor pressure. The compounds listed above are all organic compounds, and their relative volatility can be determined by comparing the strength of the intermolecular forces between their molecules.
This ranking is based on the fact that CH4 is a simple alkane compound with only London dispersion forces between its molecules. The other compounds have London dispersion forces and dipole-dipole interactions which are weaker than London dispersion forces in CH4. Hence CH4 will have the highest vapor pressure among the given compounds.
Read more about Vapor pressure:
https://brainly.com/question/2693029
#SPJ4
an empty container with a volume of 160.0 cm3 is weighed and found to have a mass of 72.3 g. the container is filled with a liquid and reweighed. the mass of the container and the liquid is 199.9 g. what is the density of the liquid to the appropriate number of significant figures?
An empty container with a volume of 160.0 cm³ is weighed and found to have a mass of 72.3 g. The density of the liquid is 0.797 g/ cm³.
The Mass of empty container = 72.3 g
The Mass of container + Liquid = 199.9 g
The Mass of Liquid =?
The Mass of Liquid = (Mass of container + Liquid) – (Mass of the empty
container)
The Mass of Liquid = 199.9 - 72.3
The Mass of Liquid = 127.6 g
The volume = 160 cm³
The density is given as:
Density = mass / volume
Density = 127.6 / 160
Density = 0.797 g/cm³
To learn more about density here
https://brainly.com/question/24575988
#SPJ4
What is the formula for this ionic crystal ?
The chemical formula of the ionic crystal is Ca₄F₈ (option D).
What is an ionic crystal?Ionic crystal in chemistry is a crystalline form of an ionic compound.
According to this question, an ionic crystal is depicted in the attached image. The green balls represent fluoride ions while the blue balls represent calcium ions.
Based on the ionic crystal, there are four (4) calcium ions and eight (8) fluoride ions, hence, the formula of the ionic crystal is Ca₄F₈.
Learn more about ionic crystal at: https://brainly.com/question/20618953
#SPJ1
polyatomic ion examples with explanation
A polyatomic ion examples with explanation are:
Carbonate (CO₃²⁻): This ion is made up of one carbon atom, three oxygen atoms, and a negative 2 charge. It is commonly found in rocks such as limestone and can also be found in baking soda.Nitrate (NO₃⁻): This ion is made up of one nitrogen atom and three oxygen atoms and it carries a negative 1 charge. It is commonly found in fertilizers and is also a component of nitric acid.What are polyatomic ion?A polyatomic ion is a group of atoms that are chemically bonded together and carry an overall electric charge. Here are a few examples of polyatomic ions:
Sulfate (SO₄²⁻): This ion is made up of one sulfur atom and four oxygen atoms, and it carries a negative 2 charge. It is commonly found in minerals such as gypsum and also in sulfate salts like Epsom salt.Lastly, Hydroxide (OH⁻): This ion is made up of one oxygen atom and one hydrogen atom and it carries a negative 1 charge. It is commonly found in water and it is the basis of many acids and bases.
Learn more about polyatomic ion from
https://brainly.com/question/16349627
#SPJ1
How many moles are in .3 g of water
Answer:
n(H2O)=0.167mol
Explanation:
n(H2O)=m/M
m(H2O)=3g, M(H2O)=18g/mol
=>n(H2O)=3/18=o.167mol
How much change in temperature would the addition of 39,231J of heat have on a 532g sample of copper?
In the compound, A is the ___, B is the ____, C is the ___.
Multiple choices:
-Hydrate
-Anhydrate
-Waters of hydration
The highlighted parts of the compound are;
A - Anhydrate
B - Waters of hydration
C - Hydrate
What is a hydrated compound?We know that a compound can be said to be hydrated if the compound does contain a water of crystallization. The implication of this is that If we have a compound that has a certain specified number of water molecules attached to it, we can say that the compound is hydrated.
The anhydrous compound is the compound that has lost its water of crystallization. We can tell that for the compound that we have, there is a water of hydration attached.
Learn more about crystallization:https://brainly.com/question/13008800
#SPJ1
a fictitious element z has an average atomic mass of 223.13 u. element z has two naturally occuring isotopes. the more abundant isotope has an exact mass of 224.75 u and a relative abundance of 62.94%. calculate the exact mass of the second isotope.
The exact mass of the second isotope is 224.15 u
The following equation can be used to get the average atomic mass:
average atomic mass = (% of the first isotope/100) x mass of the first isotope+ (% of the second isotope/100) x mass of the second isotope)
Due to this:
Initially isotope:
% = 62.94 %
Mass = 224.75 u
The second isotope is:
Since there are only two isotopes of the element, the second percentage is equal to 100 minus the first percentage.
% = 100 % - 62.94 % = 37.06 %
Assume Mass = x u.
Average Mass = 223.13 u, as stated
Thus,
average atomic mass = (% of the first isotope/100) x mass of the first isotope+ (% of the second isotope/100) x mass of the second isotope)
223.13 = (62.94 % x 224.75) +( 37.06 % x 223.13 )
100 100
When we solve for x, we obtain:
x = 224.15 u
learn more about isotope at https://brainly.com/question/11680817
#SPJ4
the rate constant for a reaction at 40.0oc is exactly three times that at 20.0oc. calculate the activation energy for the reaction. report your answer in kj/mol.
The activation energy for the reaction is 4.187 x 10⁴ J/mol.
The reaction's starting point temperature is 40.0° C
T' = 20.0° C is the reaction's final temperature.
Initial temperature's rate constant is three times higher than final temperature's.
The relationship between the Arrhenius energy and the rate constant is the basis of the presented problem. And the mathematical expression is as follows:
ln k'/k = (Eₐ/R) x (1/T-1/T')
The universal gas constant, R, is used here. And is the activation's Arrhenius energy.
As stated in the issue,
K'/k = 3
Solving as,
ln k'/k = (Eₐ/R) x (1/T-1/T')
ln 3 = (Eₐ/8.134) x (1/293-1/313)
1.098 = (Eₐ/8.134) x2.18 x10⁻⁴
Eₐ = 4.187x 10⁻⁴ J
Thus, it follows that the required amount of activation energy for the specified reaction is 4.187x 10⁻⁴ J.
Learn more about energy activation at https://brainly.com/question/28384644
#SPJ4
a separation process that depends on differing abilities of substances to form gases is called .
A separation process that depends on differing abilities of substances to form gases is called Distillation.
Distillation is a common method used to separate and purify liquids based on their different boiling points. The process involves heating a mixture of liquids to a temperature where one liquid will evaporate and form a vapor, while the other liquids will remain in a liquid state. The vapor is then condensed back into a liquid form and collected, which is then called the distillate. The distillate will be the liquid with the lowest boiling point of all the components in the mixture. This process can be repeated for different boiling point ranges and those multiple distillates will be different components of the original mixture.
Learn more about mixture here:
https://brainly.com/question/24898889
#SPJ4
a 140.0 g sample of water at 20.0 °c is mixed with 100.0 g of a certain metal at 95.0 °c. after thermal equilibrium was established, the temperature of the mixture is 24.6 °c. what is the specific heat capacity of the metal?
the specific heat capacity of the metal is 0.3427 J/g°C.
Water mass is 140.0 g.
Water started out at a temperature of 20.0 °C.
100 g is the mass of a specific metal.
Metal's initial temperature is 95.0°C.
Water and metal's combined final temperature is 24.6°C.
The water will gain heat because its initial temperature is lower than that of the metal, which will lose heat because it is at a greater initial temperature. Therefore, heat obtained by water equals heat lost by metal.
formula: (mass water)(finalT- initalT) = (mass metal)(initialT- finalT)(Cp metal) ( Cp water)
after entering the provided info we obtain,
(100g )(95°C -24.6°C)
(140.0g)(24.6°C–20.0°C) = (Cp metal) (4.184 J/g°C)
The formula is (100g)(70.4°C)(Cp metal)=(140.0g)(4.6°C)(4.184 J/g°C)
7863.7 g°C = 2694.5 J (Cp metal)
Cp metal = 2694.5% J/7863.7% g°C
Cp of metal therefore equals 0.3427 J/g°C.
To learn more about Specific heat :
https://brainly.com/question/11183316
#SPJ4
what is the entropy of this collection of training examples with respect to the target function classification?
Deciding whether or not to approve a mortgage Future changes in consumer purchase tendencies can be predicted using classification models.
A mortgage is a kind of loan used to buy or keep up real estate, such as a home, piece of land, or other construction. The borrower agrees to make a series of monthly payments, divided into principal and interest, to the mortgage lender. This frequently emerges as a succession of regular, weekly episodes. After then, the asset is forfeited as loan collateral.
Borrowers are need to fill out an application with their selected lender and fulfill a number of criteria, such as down payments and minimum credit scores. Before going on to the closing stage, mortgage applications must pass a stringent underwriting procedure.
To know more about entropy on
https://brainly.com/question/29669969
#SPJ4
Three magnesium isotopes have atomic masses and relative abundances of 23.995 amu (78.99%), 24.986 amu (10.00%), and 25.992 (11.01%). Calculate the average atomic mass of magnesium.
i’ll give brainliest
Answer:
24.3139697
Explanation:
23.995(0.7899)+24.986(0.1000)+25.992(0.1101) = 24.3139697
Which two changes would decrease the gravitational force between two objects?
Decreasing mass and increasing distance between two objects decrease the gravitational force between two objects.
What is gravitational force?The concept of gravitational force is described by Newton's Law of Universal Gravitation. This gravitational force is indeed a form of non-contact force; it is a constant attracting and constrictive force in nature.
The attraction force felt by two or even more objects into contact is known as gravitational force. The Gravitational Force Formula, which was derived from Newton's Universal Law of Gravitation, is used to calculate the gravitational force.
F=GmM/r²
From formula we can see that decreasing mass and increasing distance between two objects decrease the gravitational force between two objects.
Therefore, decreasing mass and increasing distance between two objects decrease the gravitational force between two objects.
To learn more about gravitational force, here:
https://brainly.com/question/3009841
#SPJ1
what volume of 6 m acetic acid is required to fully react with 0.5 g of sodium bicarbonate (nahco3)?
The volume of 6 M acetic acid required to fully react with 0.5 g of sodium bicarbonate is 0.099167 mL.
To determine the volume of 6 M acetic acid required to fully react with 0.5 g of sodium bicarbonate (NaHCO3), we need to use the balanced equation for the reaction between acetic acid and sodium bicarbonate.
The balanced equation is:
CH3COOH(aq) + NaHCO3(aq) → CH3COONa(aq) + H2O(l) + CO2(g)
From the balanced equation, we know that one mole of acetic acid reacts with one mole of sodium bicarbonate.
we know that the molarity is moles of solute per liters of solvent, so the number of moles in 0.5 g of sodium bicarbonate is 0.5/84 = 0.00595 mol
And since one mole of acetic acid reacts with one mole of sodium bicarbonate, we know that we need 0.00595 mole of acetic acid to fully react with 0.5 g of sodium bicarbonate.
If we know the molarity of acetic acid, we can calculate the volume of acetic acid required to react with 0.5 g of sodium bicarbonate. we have
V = n / M = 0.00595 / 6 = 0.00099167 L = 0.099167 mL
To know more about sodium bicarbonate click here:
https://brainly.com/question/8560563#
#SPJ4
HNO3 + H3PO3 → NO + H₂PO4+H₂O (Acidic)
What is the complete step by step oxidation reduction reaction?
Answer:
The reaction provided is not a redox reaction. The equation shows the neutralization reaction between Nitric acid (HNO3) and Phosphoric acid (H3PO3) to produce Nitrogen monoxide (NO), Dihydrogen Phosphate (H2PO4) and water (H2O).
When two or more acids are mixed together, they can neutralize each other. This is called a neutralization reaction. The acid and the base will react to form a salt and water. In this case, Nitric acid is the acid and Phosphoric acid is the base.
The equation for this neutralization reaction can be balanced as follows:
HNO3 + H3PO3 → NO + H2PO4 + H2O
Where HNO3 = Nitric acid
H3PO3 = Phosphoric acid
NO = Nitrogen monoxide
H2PO4 = Dihydrogen Phosphate
H2O = water
The reaction is acidic in nature due to the presence of H+ ions in the products.
In summary, the reaction provided is a neutralization reaction, not a redox reaction. The equation shows that Nitric acid and Phosphoric acid neutralize each other to form Nitrogen monoxide, Dihydrogen Phosphate and water. The reaction is
in one trial, scientist find that a 200-g sample of chalk, CaCO3, contains 80g of calcium. in a second trial, the scientist find that a 100-g sample of chalk contains 40g of calcium. explain how the data demonstrate the law of definite proportions.
According to law of definite proportion, the ratio of elements in calcium carbonate is always fixed. Thus on mole of calcium carbonate is 100 g which contains one Ca atom weighs 40 g. Thus,200 g of CaCO₃ contains 80 g of Ca.
What is law of definite proportion ?Law of definite proportion states that, every compound will maintain a definite proportion of its constituent elements always irrespective of the source and method of preparation.
Therefore, all the elements in a compound will be in a fixed ratio with total mass of the compound. There is only one Ca in one formula unit of CaCO₃.
atomic mass of Ca = 40 g/mol
molar mass of CaCO₃ = 100 g/mol/
Hence, 100 g of CaCO₃ contains 40 g of Ca, if 200 g of CaCO₃ is taken, the mass of Ca doubles to 80 g to keep the definite proportion of the composition.
Find more on law of definite proportion:
https://brainly.com/question/28458716
#SPJ1
Introduction
Use your responses from the Project Summary to describe the project goal and criteria. Add one to two sentences to describe your optimal design.
*
5000 characters remaining
Design Decisions
Use your Proposal Outline and feedback from your project director to explain how your design addresses each criterion.
The specific aims that you want the project to achieve are known as project objectives.
What is Project goal?Every choice made throughout the project life cycle will be influenced by the project objectives, which is why it's so important to articulate them as clearly as possible at the outset.
Using the SMART methodology for creating project management objectives is one of the greatest ways to ensure that your project goals are clear and explicit.
PMs and their teams may plan projects effectively and guarantee on-time, on-budget delivery by using SMART project objectives.
Therefore, The specific aims that you want the project to achieve are known as project objectives.
To learn more about Objectives, refer to the link:
https://brainly.com/question/14964361
#SPJ1
a student mixes 50.0 ml of 0.10 m pb(no3)2 solution with 50.0 ml of 0.10 m kcl. a white precipitate forms, and the concentration of the chloride ion becomes very small. which list places the concentrations of the remaining ions in order of decreasing concentration?
[ NO3-] > [K+] > [Pb2+] is correctly places the concentrations of the remaining ions in order of decreasing concentration.
As from the given data, we know that,
Pb(NO3)2 + 2KCl = PbCl2 + 2KNO3
we know,
Pb(NO3)2= 0.005mol
2KCL = 0.005mol
PbCl2 = 0.0025mol
2KNO3 = 0.005mol
SO,
K+ and NO3- spectators 2NO3- for each K+
Pb and K+ are equal but some Pb precipitate
Hence, giving the concentration order as,
[ NO3-] > [K+] > [Pb2+] and the concentration of the chloride ion becomes very small and hence it is negligible.
For more such questions on concentration, Visit:
https://brainly.com/question/17206790
#SPJ4
estimate the specific gravities (gas) for methane and propane. their molecular weights are shown inside the back cover or in the book appendices. (commercial natural gas and commercial propane are mostly methane and propane, with small amounts of other substances, which may be ignored for this problem.) which is more dangerous, a propane leak or a methane leak? why?
The specific gravity of methane is 0.554 and the specific gravity of propane is 1.52.
The specific gravity of a gas can be calculated using the formula:
Molecular Weight of Gas / Molecular Weight of Air = Specific Gravity
For methane:
Molecular weight of methane = 16.04 g/mol
Molecular weight of air = 28.97 g/mol
Specific Gravity = 16.04 g/mol / 28.97 g/mol = 0.554
For propane:
Molecular weight of propane = 44.10 g/mol
Molecular weight of air = 28.97 g/mol
Specific Gravity = 44.10 g/mol / 28.97 g/mol = 1.52
A propane leak is more dangerous than a methane leak because propane is heavier than air, so it sinks and can collect in low-lying areas such as basements and crawl spaces, where it can be ignited by a spark or flame. Methane, on the other hand, is lighter than air and tends to rise, making it less likely to accumulate in dangerous concentrations. Additionally, propane is more explosive than methane, so a propane leak can result in a larger and more destructive explosion.
To learn more about specific gravity here:
https://brainly.com/question/9100428
#SPJ4
the complete question is :
Estimate the methane and propane-specific gravities (gas). 16.04 and 44.10 molecular weights respectively. (In commercial natural gas and propane, the main components are methane and propane; minor amounts of other compounds may be disregarded for this issue.) A propane leak or a methane leak, which is more hazardous? why?
hich of the following options correctly describe entropy? select all that apply. multiple select question. the symbol for entropy is e. entropy is a measure of the energy dispersal of a system. the greater the freedom of motion of particles in a system, the greater the entropy of the system. any process that causes an increase in the entropy of a system will be spontaneous. entropy is another term for kinetic energy or energy of movement.
The options which correctly describe entropy are- Entropy is a measure of the energy dispersal of a system, The greater the freedom of motion of particles in a system, the greater the entropy of the system and Any process that causes an increase in the entropy of a system will be spontaneous.
What is the definition of entropy?Entropy is a measure of the disorder or randomness of a system, and it is often associated with the amount of energy that is unavailable to do work. The symbol for entropy is S. It is not another term for kinetic energy or energy of movement.
What is the second law of thermodynamics?The second law of thermodynamics says that the total entropy of a system either increases or will remain constant in any spontaneous process. It never decreases.
To know more about thermodynamics, visit here:
https://brainly.com/question/1368306
#SPJ4
identify tools that are ideal for cleaning glassware.
tools that are ideal for cleaning glassware Brushes and Detergent
Scrub the interior of curved glassware with warm tap water and a brush dipped in soapy water. You can flush the sink with this waste water. To avoid severe water stains, detergents, remove soap suds with deionized water. Pouring the DI water rinse through clean glassware should result in a smooth sheet. According to the University of Wisconsin Office of Chemical Safety, acid solutions such fuming sulfuric acid, diluted sulfuric acid, chromic acid solution, piranha solution, and aqua regia (a blend of nitric acid and hydrochloric acid) are used to clean laboratory glassware.
identify tools that are ideal for cleaning glassware.
1. reusable clothes
2.brushes
3. detergents
4. steel wool water
Learn more about detergents here:
https://brainly.com/question/11727239
#SPJ4
Each of the given reactions is catalyzed by an enzyme. For each reaction, classify the enzyme according to one of the six categories suggested by the International Union of Biochemistry. Consider the reaction. H 2 O + A dipeptide and water forms two amino acids. Which category does the catalyzing enzyme belong to?
Considering the given reaction, H 2 O + A dipeptide and water forms two amino acids, hydrolase category does the catalyzing enzyme belongs.
The catalyzing enzyme in the reaction H2O + A dipeptide → two amino acids belongs to the Hydrolase category. This is because the enzyme catalyzes the hydrolysis of a dipeptide, which involves the addition of water (H2O) to the dipeptide to form two amino acids. Hydrolases are enzymes that catalyze the hydrolysis of various types of biological molecules, such as carbohydrates, lipids, and nucleic acids.
1. Esterases, which catalyze the hydrolysis of esters, breaking the bond between the carboxyl and alcohol groups.
2. Lipases, which catalyze the hydrolysis of lipids, breaking the bond between the glycerol and fatty acid groups.
3. Peptidases, which catalyze the hydrolysis of peptides, breaking the bond between the amino acids.
To know more about reaction please refer: https://brainly.com/question/29039149
#SPJ4
A body is accelerated continuously. What is the form of the graph?
A. cubic
B. inverse
C. linear
D. quadratic
Answer:
B: Inverse
Explanation:
a concentrated aqueous solution of sulfuric acid (h2so4) has a density of 1.509 g/ml and contains 10% sulfuric acid by mass. calculate the molality of sulfuric acid.
Molality of sulfuric acid is 1.1.
As we know that density of solution = 1.509 = mass of solution \ Volume.
10% of [tex]H{_2}SO_4[/tex] by mass,
[tex]\frac{10}{100} \times 1.509[/tex] v (g)
As the mass of solvent [tex]=\frac{90}{100}\times 1.509 V(g)[/tex]
98 g of [tex]H{_2}SO_4[/tex] contains moles = 1,
[tex]\frac{10 \times 1.509 V g}{100}[/tex] of [tex]H{_2}SO_4[/tex] contains moles = [tex]\frac{1.509 .v}{10 \times 98}[/tex] moles
Molality = moles of solute/ Mass of solvent (kg)
=[tex]\frac{1.509 \times 100 \times 1000}{10 \times 98 \times 1.509 .V (kg)}[/tex]
= 1.1
Hence, the Molality of sulphuric acid is 1.1.
To know more about molality:
brainly.com/question/26921570
#SPJ4
what is the process of splitting a uranium atom called?
Answer:
Nuclear fission
conclusions: how do the results for methane compare to those for butane? does your experimental data verify charles's law?
The rule of conservation of mass only holds when the combined masses of the reactants and products are equal. As a result, if we know the masses of one reactant and one product, we can calculate the masses of the other reactant and product.
We know that the reactants in this case have beginning concentrations of 25.0 g of lithium and 25.0 g of bromine. The molar mass of lithium is 6.939 g/mol, whereas the molar mass of bromine is 159.808 g/mol.
In order to convert the mass of any material into a unit of moles the temperature and volume of methane and butane must be measured and recorded at various pressures and temperatures in an experiment to confirm Charles's Law. The data from the experiment must then be analyzed to determine whether the relationship between temperature and volume is direct and linear, as predicted by Charles's Law.
To learn more about Charle's law:
https://brainly.com/question/16927784
#SPJ4
the density of gold is 19.3 g/ml. what is the volume of a gold nugget that weighs 67.0 g? write your numerical answer without unit inside the box. the answer should be in three significant figures and in standard not scientific notation.
The volume of a gold nugget that weighs 67.0 g is 3.47 mL
The relationship between an object's mass and the volume it occupies is known as its density. This means that if an object's volume increases but its mass remains constant, its density will decrease.
We use the equation: to determine the mass of the solution.
ρ = m/V
whre,
ρ = density
m= mass
v= volume
so,
V= m/ρ
We receive:
Gold mass =67.0 grams.
Gold has a density of 19.3 g/mL.
Using the values in the equation above, we obtain:
V= m/ρ
V = 67.0 grams./ 19.3 g/mL.
V= 3.47 mL
Consequently, the gold nugget's volume is 3.47 mL
learn more about density at https://brainly.com/question/13692379
#SPJ4
which bonds are covalent bonds? question 19 options: a) peptide bonds b) glycosidic bonds c) phosphodiester bonds d) all of these choices are correct.
Peptide bonds, glycosidic bonds, phosphodiester bonds are covalent bonds.
A covalent bond is formed by the equal sharing of electrons by two atoms.
The bond which is formed between the first carbon atom of one monosaccharide with the four carbon atoms present in the neighboring monosaccharide unit and, which results in the formation of a polysaccharide unit is known as a Glycosidic bond. In the formation of this bond, a water molecule is released as a by-product.
A covalent bond which is formed between the carboxyl group of one amino acid and the amino group of the neighboring amino acids, is known as a peptide bond. This bond formation involves release of a water molecule as a by-product.
The phosphate-hydroxyl linkage present between two nucleotides where the phosphate group is attached to the hydroxyl group(OH) at the 5'-carbon of pentose sugar is bonded to the hydroxyl group of the 3'-carbon of the pentose sugar present in the next neighboring nucleotide. This bond is known as a phosphodiester bond.
Thus, option (d) is correct
To know more about covalent bonds here
https://brainly.com/question/2512088
#SPJ4
How many milligrams are in 5.7 grams
Answer:
5700 milligrams
Explanation:
To go to a smaller unit you move the decimal to the right.
which compound can provide the energy for chemosynthesis?(1 point) responses water water hydrogen sulfide hydrogen sulfide carbon dioxide carbon dioxide oxygen
The compound can provide the energy for chemosynthesis is the carbon dioxide.
The Chemosynthesis is the process in which the certain microbes will create the energy by mediating the chemical reactions. so that the animals that live around the hydrothermal vents will make their living from the chemicals that are coming out of the seafloor. The energy stored in the bundles or the packets is known as the photon. The compound can provide the energy for chemosynthesis is the carbon dioxide and the photons.
Thus, The compound carbon dioxide can provide the energy for chemosynthesis. Therefore the correct , option C is correct.
To learn more about chemosynthesis here
https://brainly.com/question/20848380
#SPJ4