Answer:
The soil has a percentage of water by mass of 27.8 %.
Explanation:
Keeping in mind that
Mass of Clay = Mass of water + Mass of Dry Soilwe can calculate the mass of water:
1350 g = Mass of Water + 975 gMass of Water = 375 gWe can then calculate the mass percentage of water in the soil:
375 / 1350 * 100% = 27.8 %PLEASE HELPP!
Question #9
Long Text (essay)
Summarize the arguments both for and against allowing genetically altered meats into the United States.
B
1
á
I
© 2013 Glynlyon, Inc.
< PREV
Answer:
The arguments both for and against allowing genetically altered meats into the United States is explained below in details.
Explanation:
Arguments for and against genetically altered meats:
Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.ENVIRONMENTAL RISK. STRONGER CROPS = LESS PESTICIDES. REMEMBER WHEN CIGARETTES WERE 'HARMLESS'? TAMPERING FOR TASTE. ...BIG BUSINESS EATS SMALL FARMERS. ENHANCED HEALTH. NOTHING TASTES BETTER THAN NATURE.Answer:
The arguments both for and against allowing genetically altered meats into the United States is explained below in details.
Explanation:
Arguments for and against genetically altered meats:
Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.
ENVIRONMENTAL RISK.
STRONGER CROPS = LESS PESTICIDES.
REMEMBER WHEN CIGARETTES WERE 'HARMLESS'?
TAMPERING FOR TASTE. ...
BIG BUSINESS EATS SMALL FARMERS.
ENHANCED HEALTH.
NOTHING TASTES BETTER THAN NATURE.
Explanation:
what is the correct name of Fe(CN)3?
Answer:
Iron(III) Cyanide
The pH of a sample of blood is 7.4, while gastric juice is pH 1.4. The blood sample has: Group of answer choices 0.189 times the [H ] as the gastric juice. 6 times lower [H ] than the gastric juice. one million times lower [H ] than the gastric juice 5.29 times lower [H ] than the gastric juice. 6000 times lower [H ] than the gastric juice.
Answer:
The blood sample has [H⁺] that is one million times lower than the [H⁺] of gastric juice.
Explanation:
To know the the correct answer to the question, we obtained obtained the hydrogen ion concentration [H⁺] of the blood and gastric juice. This can be obtained as follow:
For Blood sample:
pH = 7.4
Concentration of Hydrogen ion for blood [H⁺]₁ =?
pH = – Log [H⁺]₁
7.4 = – Log [H⁺]₁
Divide both side by –1
– 7.4 = Log [H⁺]₁
Take the antilog of – 7.4
[H⁺]₁ = Antilog (–7.4)
[H⁺]₁ = 3.98×10¯⁸ M
Thus, the concentration of Hydrogen ion for blood [H⁺]₁ is 3.98×10¯⁸ M
For Gastric juice:
pH = 1.4
Concentration of Hydrogen ion for gastric juice [H⁺]₂ =?
pH = – Log [H⁺]₂
1.4 = – Log [H⁺]₂
Divide both side by –1
– 1.4 = Log [H⁺]₂
Take the antilog of – 1.4
[H⁺]₂ = Antilog (–1.4)
[H⁺]₂ = 3.98×10¯² M
Thus, the concentration of Hydrogen ion for gastric juice [H⁺]₂ is 3.98×10¯² M
Finally, we shall compare the hydrogen ion concentration [H⁺] of the blood and gastric juice. This can be obtained as follow:
Concentration of Hydrogen ion for blood [H⁺]₁ = 3.98×10¯⁸ M
Concentration of Hydrogen ion for gastric juice [H⁺]₂ = 3.98×10¯² M
[H⁺]₁ / [H⁺]₂ = 3.98×10¯⁸ / 3.98×10¯²
[H⁺]₁ / [H⁺]₂ = 1×10¯⁶
Cross multiply
[H⁺]₁ = [H⁺]₂ × 1×10¯⁶
[H⁺]₁ = [H⁺]₂ / 1000000
From the calculations made above, the blood sample has [H⁺] that is one million times lower than the [H⁺] of gastric juice.
Graciella divided her grapes equally among 6 friends. If each friend received 16 grapes how many grapes did Graciella have?
Answer: She had 96 grapes.
Explanation:
Answer:
taiks
Explanation:
Were any of your substances difficult to identify as polar, nonpolar, or ionic? Explain.
Answer:
See explanation
Explanation:
A substance is classified as polar, nonpolar or ionic based on its behavior.
For the substances identified, there was no difficult in identifying each as polar, nonpolar, or ionic because since it was quite to easy identify where each belongs by looking out for whether it mixes or dissolves in our experiment.
Every substance in the experiment either mixed or dissolved during the experiment.
Hydrogen peroxide is a versatile chemical, its uses include bleaching wood pulp and fabrics and substituting for chlorine in water purification. One reason for its versatility is that it can be either an oxidizing or reducing agent. For the following reactions, identify whether hydrogen peroxide is an oxidizing or reducing agent.
a) H2O2 (aq) + 2 Fe2+ (aq) + 2 H+ + 2H20 (1) + 2 Fe3+(aq)
b) 5 H2O2 (aq) + 2 MnO4 (aq) + 6 H+ (aq) → 8 H20 (1) + 2 Mn2+ (aq) + 5 O2 (g)
Answer:
Explanation:
a )
H₂O₂ (aq) + 2 Fe²⁺ (aq) + 2 H⁺ = 2H20 (l) + 2 Fe³⁺(aq)
Here oxidation number of Fe is increasing from + 2 to + 3 so it is being oxidized . Hence H₂O₂ is acting as oxidizing agent here .
b )
5 H₂O₂ (aq) + 2 MnO₄⁻¹ (aq) + 6 H⁺ (aq) → 8 H20 (l) + 2 Mn⁺² (aq) + 5O₂ (g)
In this reaction, oxidation number of Mn is reducing from + 7 to + 2 so it is being reduced . Here H₂O₂ is acting as reducing agent .
Calculate the mass in grams for 2.28 moles of N2?
Mole measure the number of elementary entities of a given substance that are present in a given sample. The mass of [tex]N_{2}[/tex] with 2.28 mol is 63.84g.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. Mole is inversely proportional to the molar mass of respective molecule. 1 mole contains Avogadro number of atoms, ions or molecules. Mole is extensive property as it depends on the quantity of substance.
mole of [tex]N_{2}[/tex] =given mass of [tex]N_{2}[/tex] ÷molar mass of nitrogen gas
mass of [tex]N_{2}[/tex]= mole of [tex]N_{2}[/tex] ×molar mass of nitrogen gas
mole of [tex]N_{2}[/tex]= 2.28mol
Substituting the values in the formula we get,
mass of [tex]N_{2}[/tex]= 2.28mol ×28g/mole
mass of [tex]N_{2}[/tex]= 2.28mol ×28
mass of [tex]N_{2}[/tex]=63.84g
Therefore the mass of [tex]N_{2}[/tex] is 63.84g with 2.28 mole is 63.84g.
To know more about mole, here:
https://brainly.com/question/15209553
#SPJ2
if a molecular formula is C8H12O2, what is the empirical formula
Answer:
C₄ H₆ O
Explanation:
The molecular formula of the compound is given as:
C₈ H₁₂ O₂
The molecular formula of a compound is expresses the true number of atoms within a compound.
The empirical formula gives the simplest ratio of the atoms within a compound.
Elements C H O
Number of atoms 8 12 2
Divide through by a
Common factor 8/2 12/2 2/2
4 6 1
The empirical formula therefore is C₄ H₆ O
The first red (632.8 nm) Helium Neon gas laser was reported by White and Rigdon from Bell Labs in 1962. The laser was a discharge tube that was 1.2 m long with a 7 mm diameter. A He-Ne ratio of 10:1 was used with a total pressure of 0.00092 atm. This is a really low pressure with a really small amount of He and Ne. We want to try making a new laser with the same discharge tube with 5 mol Helium and 1 mol Neon. For the new laser with 5 mol He and 1 mol Ne, calculate the following quantities. Assume room temperature (298.15 K) and that the gasses are ideal.
a. What is the total volume (cm^3)?
b. What is the mole fraction of He?
c. What is the mole fraction of Ne?
d. What is the partial pressure of He (in atm)?
e. What is the partial pressure of Ne (in atm)?
f. What is the total pressure of the new laser tube (in atm)?
Answer:
a) Total Volume = 46.18 cm³
b) Mole[tex]_{fraction}[/tex] (He) = 0.8333
c) Mole[tex]_{fraction}[/tex] (Ne) = 0.1666
d) Partial Pressure P[tex]_{He}[/tex] = 2648.68 atm
e) Partial Pressure P[tex]_{Ne}[/tex] = 529.73 atm
f) total pressure of the new laser tube = 3178.41 atm
Explanation:
Given that;
height of of discharge tube h = 1.2 m = 1.2 × 100 = 120cm
diameter of the tube D = 7 mm = 0.7cm
Radius = D/2 = 0.7/2 = 0.35 cm
a) What is the total volume (cm³)?
Volume = πr²h
we substitute
Volume = π × (0.35)² × 120
Volume = 46.18 cm³
b) What is the mole fraction of He?
Mole fraction of Helium will be;
Mole[tex]_{fraction}[/tex] (He) = Moles of He / Total Moles ( He + Ne)
given that; 5 mol He and 1 mol Ne
Mole[tex]_{fraction}[/tex] (He) = 5 / ( 5 + 1 )
Mole[tex]_{fraction}[/tex] (He) = 5 / 6
Mole[tex]_{fraction}[/tex] (He) = 0.8333
c) What is the mole fraction of Ne?
Mole fraction of Neon will be;
Mole[tex]_{fraction}[/tex] (Ne) = Moles of Ne / Total Moles ( He + Ne)
given that; 5 mol He and 1 mol Ne
Mole[tex]_{fraction}[/tex] (Ne) = 1 / ( 5 + 1 )
Mole[tex]_{fraction}[/tex] (Ne) = 1 / 6
Mole[tex]_{fraction}[/tex] (Ne) = 0.1666
d) d. What is the partial pressure of He (in atm)?
using ideal gas equation;
P[tex]_{He}[/tex] = nRT/V
where n is number or amount of moles( 5 )
R is the universal gas constant ( 0.08205 L-atm.mol⁻¹K⁻¹
T is temperature ( 298.15 K)
And V is the volume; ( 46.18 cm³ = 46.18/1000 = 0.04618 L )
so we substitute
P[tex]_{He}[/tex] = (5 × 0.08205 × 298.15) / 0.04618
P[tex]_{He}[/tex] = 122.316 / 0.04618
P[tex]_{He}[/tex] = 2648.68 atm
e) What is the partial pressure of Ne (in atm)?
P[tex]_{Ne}[/tex] = (1 × 0.08205 × 298.15) / 0.04618
P[tex]_{Ne}[/tex] = 24.463 / 0.04618
P[tex]_{Ne}[/tex] = 529.73 atm
f) What is the total pressure of the new laser tube (in atm)?
total pressure of the new laser tube will be;
= P[tex]_{He}[/tex] + P[tex]_{Ne}[/tex]
= 2648.68 atm + 529.73 atm
= 3178.41 atm
total pressure of the new laser tube = 3178.41 atm
Which of the following compounds is likely to make the best conductor when
dissolved in water?
a. SO2
b. C6H1206
c. KBr
d. CO
Answer:
c. KBr .
Explanation:
Hello!
In this case, since electrolytes are substances that are able to carry electric current in the form of electrons via ions, those that are ionic are said to have the greatest capacity to conduct the electricity; in such a way, since SO2, C6H12O6 and CO are non-ionic molecules but covalent, they are not good conductor, therefore the best conductor would be c. KBr as it is an ionic compound due to the electronegativity of the K-Br bond.
Best regards!
Calculate the moles of ammonia present in a 5.590 g sample if the molar mass of ammonia is 17.030 g/mol
Answer:
Number of moles = 0.328 moles.
Explanation:
Given the following data;
Mass = 5.590 g
Molar mass = 17.030 g/mol
To find the number of moles;
[tex] Number \; of \; moles = \frac {mass}{molar mass} [/tex]
Substituting into the equation, we have
[tex] Number \; of \; moles = \frac {5.590}{17.030} [/tex]
Number of moles = 0.328 moles.
My labmate discovered a new compound and wanted to try to determine what it could be. We noticed that when mixed with an acid, it formed a white solid. What type of chemical reaction did the new chemical just undergo?
Answer:
it went under the process known as crystalization
Explanation:
am a chemist
What is the main type of energy conversion that happens to a ball thrown in
the air as it goes up?
A. Kinetic energy to gravitational potential energy
B. Gravitational potential energy to kinetic energy
C. Chemical potential energy to kinetic energy
D. Kinetic energy to chemical potential energy
What is the molecular formula for the model below?
A chemist is studying the rate of the Haber synthesis: N2 + 3H2 2NH3
Starting with a closed reactor containing 1.25 mol/L of N2 and 0.50 mol/L of H2, the chemist finds that the H2 concentration has fallen to 0.25 mol/L in 44 seconds.What is the N2 concentration after 44 seconds?
Answer:
1.17 M
Explanation:
Step 1: Write the balanced equation
N₂ + 3 H₂ ⇒ 2 NH₃
Step 2: Calculate the rate of disappearance of H₂
We will use the following expression.
rH₂ = - Δ[H₂]/t = - (0.25 M - 0.50 M)/44 s = 0.0057 M/s
Step 3: Calculate the rate of disappearance of N₂
The molar ratio of N₂ to H₂ is 1:3.
0.0057 mol H₂/L.s × 1 mol N₂/3 mol H₂ = 0.0019 mol N₂/L.s
Step 4: Calculate the final concentration of N₂
We will use the following expression.
[N₂] = [N₂]₀ - rN₂ × t
[N₂] = 1.25 mol/L - 0.0019 mol/L.s × 44 s
[N₂] = 1.17 M
What is the molarity of a solution that contains 25.3 g of NaCl in 111 mL of solution?
-14.6 M
-3.90 M
-0.25 M
-5.52 M
Answer:
"3.90M" if approximate
Explanation:
if u didn't understood why i converted volume from millilitres to litre then refer defination of Molarity.
hope it help:)
Samples of different materials, A and B, have the same mass, but the sample
of A is higher in density. Which statement could explain why this is so?
A. The sample of material A has greater volume than the sample of
material B.
B. The particles that make up material B are more closely packed
together than the particles that make up material A.
C. The particles that make up material A have more mass than the
particles that make up material B.
D. The particles that make up material B have more mass than the
particles that make up material A.
SUBMI
C. The particles that make up material A have more mass than the particles that make up material B.
The correct option is (c) The particles that make up material A have more mass than the particles that make up material B.
A substance containing atoms that are smaller, more massive, and close together will have a higher density. A substance will have a lower density if its larger, lighter atoms are spaced farther apart.The distances between the particles in each state of matter determine how dense solids, liquids, and gases are.Will the density of a material always be the same?Density is an intensive property. This means that regardless of the object's shape, size, or quantity, the density of that substance will always be the same. Even if you cut the object into a million pieces, they would still each have the same density. It is because density in an intensive property of matter.Learn more about Density of a material brainly.com/question/1733081
#SPJ2
PLEASE HELP BRAINLIEST AND 15 points.
1. Which substance is nonvolatile ?
(1.5 Points)
Substance B, boiling point of 105 °C
Substance C, boiling point of 25 °C
Substance A, boiling point of 75 °C
Substance d, boiling point of 45 °C
Answer:
Substance B, boiling point of 105 °C
Explanation:
Non volatile substances have high boiling points
Hydrogen is the only atom that does not
have __electrons in the 1st energy
level/ shell.
Answer:
2
Explanation:
the number of H is 1, it means the only electron is on the energy level (1st level, s-electron). All the elements have 2 s-electrons on the 1st energy level.
The change in entropy is related to the change in the number of moles of gas molecules. Determine the change in moles of gas for each of the reactions and decide if the entropy increases decreases or has little to no change.
The given question is incomplete. The complete question is:
The change in entropy is related to the change in the number of moles of gas molecules. Determine the change in moles of gas for each of the reactions and decide if the entropy increases decreases or has little to no change:
A. [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex]
B. [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)[/tex]
C. [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]
D. [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex]
Answer: A. [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex] : decreases
B. [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2(g)[/tex] : decreases
C. [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]: no change
D. [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex] : increases
Explanation:
Entropy is defined as the randomness of the system.
Entropy is said to increase when the randomness of the system increase, is said to decrease when the randomness of the system decrease and is said to have no change when the randomness remains same.
In reaction [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex], as gaseous reactant is changed to solid product, entropy decreases.
In reaction [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)[/tex], as 4 moles of gaseous reactants is changed to 2 moles of gaseous product, entropy decreases.
In reaction [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex], as 3 moles of gaseous reactants is changed to 3 moles of gaseous product, entropy has no change.
In reaction [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex] , as 1 mole of gaseous reactant is changed to 3 moles of gaseous product, entropy increases.
Suppose two students grab an end of a rope. Both shake a rope once in a upward direction to create crests traveling at each other. What would you see when crests meet? What type of interference does this show?
Answer:
This creates destructive interference.
Explanation:
When the two ends meet they will cancel each other out.
Both students are shaking the rope in the upward direction. Hence their crest will meet up and form the constructive interference pattern. The intensity of the increases.
What is constructive interference ?When two waves moves in phase, their crest or troughs add up and the amplitude of the wave increases. This phenomenon is called constructive interference.
If the two waves are passing out of phase to each other then they undergo destructive interference. The amplitude of the destructive interference pattern reduces from their initial values.
Here, both students are shaking the rope in the upward direction. Thus, they are in moving in phase. Hence their crest will meet up and form the constructive interference pattern. The intensity of the increases.
Find more on interference?
https://brainly.com/question/16098226
#SPJ5
In a laboratory setting, concentrations for solutions are measured in molarity, which is the number of moles per liter (mol/L). Concentrations are often converted to more common units on the labels of household products. For a particular brand of bleach, the concentration of sodium hypochlorite (NaClO) is reported on the bottle as 7.25% by mass. The following information can thus be used to calculate the molarity of NaClO in the bleach:
• 1L of bleach has a mass of 1,100 grams.
• 7.25% of the mass of bleach is NaClO.
• 1 mol of NaClO has a mass of 74.44 grams.
What is the molarity (mol/L) of NaClO in the bleach?
A.0.097
B.0.93
C.1.07
D.79.75
Answer:
its C
Explanation:
1/74.44 * 79.75 = 1.07
The molarity (mol/L) of NaClO in the bleach, given the data is 1.07 mol/L (Option C)
What is molarity?Molarity is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:
Molarity = mole / Volume
How to determine the mass of NaClO in the bleachMass of bleach = 1100 gPercentage of NaClO = 7.25%Mass of NaClO = ?Mass of solute = percent × mass of solution
Mass of NaClO = 7.25% × 1100
Mass of NaClO = 0.0725 × 1100
Mass of NaClO = 79.75 g
How to determine the mole of NaClO Mass of NaClO = 79.75 gMolar mass of NaClO = 74.44 g/moleMole of NaClO =?Mole = mass / molar mass
Mole of NaClO = 79.75 / 74.44
Mole of NaClO = 1.07 mole
How to determine the molarity Mole of NaClO = 1.07 moleVolume = 1 L Molarity of NaClO =?Molarity = mole / Volume
Molarity of NaClO = 1.07 / 1
Molarity of NaClO = 1.07 mol/L
Learn more about molarity:
https://brainly.com/question/9468209
#SPJ6
1. How do organisms maintain homeostasis?
Answer:
Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them.
Which of the following statements does not describe the structure of an atom?
A) The electron cloud is a small and compacted space around the nucleus.
B) Inside the nucleus of an atom are protons and neutrons.
C) Protons are positively charged sub-atomic particles.
D) Electrons are negatively charged sub-atomic particles.
I need a help please!
Answer:
B. KBr + F2
Explanation:
In displacement reactions (reactions in which an element replaces another element in a compound) like these, reactive element displaces the less reactive element.
A. NaBr + I2
This reaction will not occur because Iodine is not able to displace bromine from the compound.
B. KBr + F2
This reaction will occur because flourine is more reactive and hence is able to displace bromine from the reaction.
C. LiF + Cl2
This reaction will not occur because chlorine is not able to displace flourine from the compound.
D. NaCl + I2
This reaction will not occur because Iodine is not able to displace Chlorine from the compound.
In 1932, Robert Emerson and William Arnold used isolated spinach chloroplasts to determine that it requires 2,400 chlorophyll molecules to generate one O2 molecule. Based on this number and your understanding of where and how O2 is formed in chloroplasts, if a spinach chloroplast absorbs 720 photons, then how many resonance energy transfer reactions occur in the light-harvesting complexes and how many O2 molecules are formed
Answer:
There will be 216,000 energy transfer reactions
90 [tex]O_{2}[/tex] molecules will be formed
Explanation:
since 2400 chlorophyll molecules = ( 1 ) [tex]O_{2}[/tex] molecule
hence there will be 8 photons absorbed in this process
for 720 absorbed photons
The number of [tex]O_{2}[/tex] molecules formed = 720 / 8 = 90 molecules of [tex]O_{2}[/tex] molecule formed
Total number of resonance energy transfer reactions
( 1 ) [tex]O_{2}[/tex] molecule = 2400 molecules
hence 90 molecules of [tex]O_{2}[/tex]
= 2400 molecules * 90 molecules
= 216000 energy transfer reactions
6.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 26. g/mol, is burned completely in excess oxygen, and the mass of the products carefully measured:
product mass
carbon dioxide 20.31g
water 4.16 g
Use this information to find the molecular formula of X
Answer:
C2H2
Explanation:
Mass of Carbon in CO2[tex]= (12/44) (20.31)[/tex] grams [tex]= 5.54[/tex] gram
Mass of hydrogen in H2O [tex]= (2/18)(4.26)[/tex] grams [tex]= 0.46[/tex] gram
We will calculate the % of C and H in the sample
% C [tex]= (5.54/6) * 100 = 92[/tex]%
% H [tex]= (0.46/6)*100 = 7.7[/tex]%
Number of mole of C [tex]= 92/12 = 7.69[/tex]
Number of mole of H [tex]= 7.67/1 = 7.67[/tex]
Fractional share of C [tex]= 7.69/7.67 = 1[/tex]
Fractional share of H [tex]= 7.67/7.67 = 1[/tex]
Empirical Formula = CH
Empirical Mass [tex]= 12+1 = 13[/tex]
Molecular mass [tex]= 26[/tex]
Molecular Formula – CHn
N [tex]= 26/13 = 2[/tex]
Molecular Formula = C2H2
Use this equation for the next question:
2NaOH + H2SO4 ® Na2SO4 + 2H20
If a reaction produces 0.75 moles Na2SO4, how many moles of NaOH were used?
0.75 moles NaOH
2 moles NaOH
.375 moles NaOH
1.5 moles NaOH
Allows ingestion and breaks down food so that nutrients can be absorbed???
Answer:
Salivation allows the ingestion of food while digestive juices aids breakdown of food and absorption of nutrients.
Explanation:
When food is taken into the mouth, the presence of food triggers a nervous reflex that causes the salivary gland to produce saliva in the mouth. Once the food particles have been ingested the digestive system breaks down the food into smaller components with the aid of the digestive juices.
When 271. mg of a certain molecular compound X are dissolved in 25.0g of benzene C6H6, the freezing point of the solution is measured to be 0.5°C. Calculate the molar mass of X.
If you need any additional information on benzene, use only what you find in the ALEKS Data resource. Also, be sure your answer has a unit symbol, and is rounded to 2 significant digits.
molal freezing point depression constant (Kf)
°C·kg·mol−1 of benzene is 5.07
Answer:
11g/mol is the molar mass of X
Explanation:
The freezing point depression occurs in a solvent by the addition of a solute. The equation is:
ΔT = Kf*m*i
Where ΔT is change in freezing point (5.5°C - 0.5°C = 5.0°C)
Freezing point of benzene is 5.5°C
Kf is molal freezing point depression of benzene (5.07°C*kg/mol)
m is molality of the solution in moles/kg of solvent
And i is Van't Hoff factor (1 for all solutes dissolved in benzene)
Replacing to solve molality:
5.0°C = 5.07°C*kg/mol*m*1
0.986mol / kg = molality
As the mass of the solvent is 25.0g = 0.025kg:
0.025kg * (0.986mol/kg) = 0.0247 moles
As molar mass of X is the ratio between mass in grams and moles, the molar mass of X is:
0.271g / 0.0247moles =
11g/mol is the molar mass of X