1. Calculate the molarity of a solution containing 49.3g of dissolved naphthalene (C10H8) in 217g benzene (C6H6).

2. A solution is prepared by mixing 94.2g of H2O, and 58.7g of ethanol, C2H5OH. Determine the mole fractions of each substance.

3. If you use 2.17mol of sucrose (C12H22O12) and dissolve this into 0.500kg of H2O, what will be the change in the freezing point of your solution? The freezing point depression of water (Kf) is 1.86 degrees Celsius/m.

Answers

Answer 1

Answer:

1. 1.56 M

2. Water →  0.803

Ethanol → 0.197

3. - 8.07°C

Explanation:

1. To solve this problem, we need benzene's density in order to determine the volume.

We assume the volume of solvent, as the volume of solution

Density for benzene is 0.8786 g/mL.

Density = m/V → V = m/density

Volume = 217 g /0.8786 g/mL = 247 mL

We convert the mass to moles and then, to mmoles

49.3 g . 1mol / 128g . 1000mmol / mol = 385.1 mmol

M = 385.1 mmol / 247mL = 1.56 M

2. We determine moles of each, solute and solvent

94.2 g. 1mol /18g = 5.23 moles of water

58.7 g . 1mol /46g = 1.28 moles of ethanol.

Total moles = 5.23 + 1.28 = 6.51

Mole fraction of water = Moles of water / Total moles

Mole fraction of ethanol = Moles of ethanol / Total moles

Water → 5.23 / 6.51 = 0.803

Ethanol →  1.28 / 6.51 = 0.197

3. Freezing point depression → ΔT = Kf . m . i

i = Van't Hoff factor, ions that are present in the solution.

As the solute is organic, i = 1.

Kf = 1.86 °C/m

m = molality (moles of solute in 1kg of solvent)

2.17 mol / 0.5kg = 4.34 m

ΔT = Freezing T° of pure solvent - Freezing T° of solution.

We replace data → 0° - Freezing T° of solution = 4.34m . 1.86°c/m . 1

Freezing T° of solution = - 8.07°C


Related Questions

Which two statements describe what happens to the nuclei of atoms during a fusion reaction? O A. Large nuclei break apart into two or more smaller nuclei. O B. A small amount of mass in the nuclei that combine is converted to energy. O c. Each nucleus formed has fewer protons than each original nucleus had. O D. Nuclei with small masses combine to form nuclei with larger masses.​

Answers

Answer:

D. Nuclei with small masses combine to form nuclei with larger masses.

B. A small amount of mass in the nuclei that combine is converted to energy

Explanation:

A nuclear fusion, in contrary to fission, is the process by which the nuclei of two atoms combine to form a much larger atom with a large nuclei. Likewise, during a fusion reaction, a large amount of energy is released from the small amount of mass in the nuclei (two) that combines.

According to this question, the following are true of a fusion reaction:

- Nuclei with small masses combine to form nuclei with larger masses.

- A small amount of mass in the nuclei that combine is converted to enormous energy.

1.Which of the following would decrease the rate of a chemical reaction?
A Increase the temperature
B Reduce the concentration of a reactant
C Increase the concentration of a reactant
D Add a catalyst

Answers

Answer:

d.) add a catalyst

Explanation:

ae per I know this is Ur , but I am not sure so u check it

B. Reduce the concentration of a reactant

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another.When the surface area of reactants is more the sites available for the collisions increase. More collisions between the reactants increases the rate of a chemical reaction. Decreasing the surface area of reactants decreases available site for collision. This eventually decreases the rate of a chemical reaction.To decrease the rate of a chemical reaction, B. Reduce the concentration of a reactant

For more information:

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write down the formula for B
example:
Hydrogen + Fluorine = Hydrogen Fluorine

help

Answers

Answer:

P³⁻ + Cl⁻ --> PCl₃

Explanation:

PCl₃: phosphorus trichloride. prefix in front of chloride is "tri"–meaning three.

Answer:

phosphorus + chlorine = phosphorus trichloride

(He asked for word equation)

In the graphic,
X represents which element?
31
x
15

Answers

Answer:

B. X represents phosphorus

Explanation:

In an isotope symbol, you write the mass number above the atomic number. So the 31 represents the mass of the protons and neutrons of the element added together, and the 15 represents the atomic number or the total number of protons in the nucleus.

Pleaseeee help me
balance the following formula equation Al(s) + CuCl2 (aq) = AICI3 (aq) + Cu(s) Coloress​

Answers

Answer:

[tex]2Al (s) + 3CuCl2( aq) --> 2AlCl3 (aq) + 3Cu(s)[/tex]

Explanation:

The main thing for this equation is to follow the amount on each side. Count each element on each side. Then by looking at the numbers figure out what numerical digit would make them equal.

For example:

On the left we have

Cu=1 and Cl=2.

But on the right we have

Cu=1 and Cl=3.

In order for them to be the same, we must add a coefficient of 3 to CuCl2 (aq0  on the left and a coefficient of 3 to Cu(s) on the right.

Concerning the structure of molecules, the biggest factor that affects solubility is
Your answer:
A. polarity
B. tarnish
C. mixiness

Answers

Answer:

A

Explanation:

Have a nice day

It’s A, polarity. Hope that helps

I can determine the molar mass of an element by looking on the Answer under the atomic mass for the element.

Answers

Answer:

YES that is the molar mass can be found as the atomic mass of a single atom, BUT when you get to larger molecules your molar mass will be a combination of atomic masses.

Explanation:

What does the prefix “geo” mean?
Please Help
I will give you Brainlist

Answers

derived from a greek word meaning “Earth” in most cases it means “global” or relate to the Earth somehow

I need help I tried many times and I don’t get it

Answers

Answer: ummm what is this cause I don't get it either

Explanation:

i need help with this to lol

Separation units often use membranes, absorbers, and other devices to reduce the mole fraction of selected constituents in gaseous mixtures. Consider a mixture of hydrocarbons that consists of 62 percent (by volume) methane, 28 percent ethane, and 10 percent propane. After passing through a separator, the mole fraction of the propane is reduced to 1 percent. The mixture pressure before and after the separation is 100 kPa. Determine the change in the partial pressures of all the constituents in the mixture.

Answers

Answer:

See explanation

Explanation:

We first obtain the mole fraction of propane at the start and end;

0.01 = x/0.62 + 0.28 + x

0.01[0.62 + 0.28 + x] = x

0.01[0.9 + x] =x

9 * 10^-3 + 0.0.1x = x

9 * 10^-3 = x - 0.0.1x

9 * 10^-3 = 0.99x

x = 9 * 10^-3/0.99

x = 9.09 * 10^-3

After

For methane

0.62/ 0.28 + 0.62 + 9.09 * 10^-3     = 0.68

For ethane

0.28/0.28 + 0.62 + 9.09 * 10^-3       =0.31

Change in partial pressure of methane = (0.68 - 0.62) * 100kPa = 6 kPa

Change in partial pressure of ethane = (0.31 - 0.28) * 100kPa = 3 kPa

Change in partial pressure of propane= (0.01 - 0.1) * 100kPa = -9 kPa

Carbon dioxide goes into a plant's leaves when it's photosynthesizing is this an example of diffusion or osmosis or neither?

Answers

Answer:

diffusion

Explanation:

plants have stomata at the bottom of their leaves. these allow for CO2 to diffuse in and out of the plant.

A gas sample occupies 200 mL at 760 mm Hg. What volume does the gas occupy at 400 mm Hg?

Answers

Answer:

201.9

Explanation:

when you divided 760 with 400 yo get 19.0 the add it with 200 you get that answer

What type of reaction is...
(NH4)2CO3(aq) → NH3(g) + CO2(g) + H2O(l)

a. combustion
b. single replacement
c. synthesis
d. double replacement
e. decomposition

Answers

Answer:

d: double replacement

Explanation:

We have that for the Question "What type of reaction is...

(NH4)2CO3(aq) → NH3(g) + CO2(g) + H2O(l)

" it can be said that

(NH4)2CO3(aq) → NH3(g) + CO2(g) + H2O(l) is a decomposition reaction

Option E

From the question we are told

What type of reaction is...

(NH4)2CO3(aq) → NH3(g) + CO2(g) + H2O(l)  

a. combustion

b. single replacement

c. synthesis

d. double replacement

e. decomposition

Generally

We have that a combustion is a reaction with oxygen to release energy a

it is in the form of

[tex]X+0_2 ---CO_2+H_2O[/tex]

double replacement

in this reaction two ionic compounds share ions to create two variant compounds with the same amount of ions

decomposition

This occurs when a compound is broken down into smaller compounds

Therefore

(NH4)2CO3(aq) → NH3(g) + CO2(g) + H2O(l) is a decomposition reaction

Option E

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How do the ideas of electrolytes and IV fluids relate?

Answers

Answer:

Electrolytes, particularly sodium, help the body maintain normal fluid levels in the fluid compartments because the amount of fluid a compartment contains depends on the amount (concentration) of electrolytes in it. If the electrolyte concentration is high, fluid moves into that compartment (a process called osmosis).

Explanation:

Answer:

Electrolytes are minerals in your body that have an electric charge. They are in your blood, urine, tissues, and other body fluids. Electrolytes are important because they help

Balance the amount of water in your body

Balance your body's acid/base (pH) level

Move nutrients into your cells

Move wastes out of your cells

Make sure that your nerves, muscles, the heart, and the brain work the way they should

Sodium, calcium, potassium, chloride, phosphate, and magnesium are all electrolytes. You get them from the foods you eat and the fluids you drink.

The levels of electrolytes in your body can become too low or too high. This can happen when the amount of water in your body changes. The amount of water that you take in should equal the amount you lose. If something upsets this balance, you may have too little water (dehydration) or too much water (overhydration). Some medicines, vomiting, diarrhea, sweating, and liver or kidney problems can all upset your water balance.

Treatment helps you to manage the imbalance. It also involves identifying and treating what caused the imbalance.

hope it's help you plz mark as brain list

How many kJ are 3,340J?

options:

3,340,000 kJ


334,000 kJ


3.340 kJ


33.40 kJ

Answers

The answer I believe is 3.340kj.

What can the period number of an element tell us about that element?

Answers

Answer:

All of the elements in a period have the same number of atomic orbitals.

Explanation:

A friend tells you that's after a candle burn there is less matter than before the flame was lit is your friend correct explain why or why not

Answers

Answer:

See explanation

Explanation:

The law of conservation of matter states that "matter cannot be created or destroyed. In a physical change, substances can change form, but the total mass remains the same."(Virginia)

Hence, the quantity of matter present before and after the candle burn must remain the same in accordance with this law stated above.

Hence, my friend was not correct.

Drag each item to show if it is matter or not matter.

light bulb added to
sunlight


heat


lamp


matter

light bulb


not matter

Answers

Only physical things have matter

Q 20.17: In IR spectroscopy, a conjugated ketone will produce a C=O signal at a ___________________ wavenumber, compared with a non-conjugated ketone of similar structure.

Answers

Answer:

See explanation

Explanation:

Infrared spectroscopy is concerned with transitions between vibrational energy levels. Each infrared active vibration leads to a change in dipole moment.

A ketone compound contains the -C=O group whose signal normally occurs at about 1710 cm-1.

A conjugated ketone is one in which the -C=O group is attached to the -C=C  group. This leads to delocalization and reduces the electron density of the C=O  double bond, which weakens this bond hence lowering the stretching frequency of the  -C=O bond from  1710 to about 1680cm-1.

If you had 3.6 moles of AI(NO3)3, how many grams would you expect to have?

Answers

766.7856 g

Molecular weight of Aluminium Nitrate is 212.996 g/mol. 3.6 moles of Aluminium Nitrate is: 212.996 × 3.6 = 766.7856

Is the water found in the watershed clean and safe for drinking?

(No plagiarism & will give brainliest)

Answers

i heard that most of the time water found in watersheds aren’t usually clean nor safe for drinking, but i know that there are very few that are somewhat safe for drinking. It’s just not usually common to find clean and healthy watersheds though.

Needing help please help me

Answers

Answer:

18. E. 0%

19. D. 25%

Explanation:

Question 18:

Let's use "B" to represent the dominant allele of "light blue skin", and

"b" for recessive "light green skin".

Squidward => BB - light blue skin

Squidward's bride => bb - light green skin

When they cross, they will have the following offsprings:

(BB) × (bb) - Parent

(Bb) (Bb) (Bb) (Bb) - Offspring

All the offspring would be light green skin. The dominant allele of light green skin will express itself over the recessive allele.

Therefore, the chances of Squidward and his bride having light green skin is 0%

Question 19:

Squidward's son => Bb - light blue skin

Squidward's son's bride => Bb - light blue skin

(Bb) × (Bb) - parent

(BB) (Bb) (Bb) (bb) - offspring

They will have the following offspring:

BB and Bb - light blue - 75%

bb - light green - 25%

Chance of having offspring with light green skin is 25%

A scientist is using robots to perform thousands of experiments on different
chemical compounds to see how they affect cancer cells. What is this
process called?
A. An intravenous solution
B. Evaluating test results
C. Screening
D. Engineering process

Answers

A scientist is using robots to perform thousands of experiments on different chemical compounds to see how they affect cancer cells.This process is called Screening.

What is screening?

The method to test diseases and health condition of body used by scientist and doctor is called screening. The screening helps to find problem earlier and treat them.

What is an intravenous solution?The liquid given to replace water, sugar and salt needed if you are ill or having operation.There are three type of an intravenous solution, isotonic, hypotonic and hypertonic.This an intravenous solution used in an intravenous therapy.

What is evaluating test?The process by which  of system and component are compared  against requirement and specification through testing. The result of the evaluating test is called Evaluating test results

What is  Engineering process?The process used by Engineer design and create functional products. This process is a series of steps.

To learn more about chemical compounds here.

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#SPJ3

Answer: screening

Explanation:

Need help with this (Chemistry)​

Answers

Answer:

State is shown inside the parenthesis.

s is for solid

aq is for aqueous solutions

l for liquid

Bombardier beetles release a burst of hot chemical spray with a popping sound. The chemical is sprayed from a structure present under the belly of the beetles.

Which is the likely advantage of such a behavior?


It allows the beetles to attract mates.

It allows the beetles to move obstacles out of their paths.

It allows the beetles to escape from predators.

It allows the beetles to stay warm in cold conditions.

Answers

It allows the beetles to escape from predators

It allows beetles to repel predators and stay safe just like skunks.

Methanol, CH3OH, is the simplest of the alcohols. It is synthesized by the reaction of hydrogen and carbon monoxide. Write chemical reactions. If 500 mol of CO and 750 mol of H2 are present, which is the limiting reactant?

Answers

Answer:

The limiting reactant is H₂

Explanation:

The reaction of hydrogen (H₂) and carbon monoxide (CO) to produce methanol (CH₃OH) is the following:

2H₂(g) + CO(g) → CH₃OH(g)

From the balanced chemical equation, we can see that 1 mol of CO reacts wIth 2 moles of H₂. So, the stoichiometric ratio is:

2 mol H₂/1 mol CO = 2.0

We have 500 mol of CO and 750 mol of H₂, so we calculate the ratio to establish a comparison:

750 mol H₂/500 mol CO = 1.5

Since 2.0 > 1.5, we have fewer moles of H₂ than are needed to completely react with 500 moles of CO. In fact, we need 1000 moles of H₂ and we have 750 moles. So, the limiting reactant is H₂.

Developing Scientific knowledge
Fill in each blank with the word that best completes the statement
Scientists develop knowledge by making
about the natural world that may lead to a
scientific question
A scientific question may lead to an)
which can be tested
The results of
can lead to changes in scientific knowledge.

Answers

Answer:

Scientists develop knowledge by making observation about the natural world that may lead to a scientific question.

A scientific question may lead to a(n) hypothesis which can be tested.

The results of experimentation can lead to changes in scientific knowledge.

Explanation:

In the process of developing scientific knowledge, scientists carry out series of observations on what happens in the natural world. This helps them to develop scientific questions. These scientific questions drawn can then lead to hypotheses which are testable.

The testing process leads to experimentation. It is in this process that much scientific questions receive answers. Testing actually lies at the core of scientific inquiry for all scientists. Whatever hypothesis made must always be tested.

The result of the testing or experimentation brings changes in scientific knowledge.  

Scientists are now able to use the genetic code of organisms to find out more about their evolutionary history. How is this most likely to impact classification

Answers

The group of choices associated with the given question are as follows:

Organisms once thought to be unrelated may be found to be related.

Mode of nutrition of some organisms may change.

Organisms that do not have a backbone may develop one.

All multicellular organisms may be found to be prokaryotes

Answer:

The correct answer would be - Organisms once thought to be unrelated may be found to be related

Explanation:

Classification of the organisms is based on the shared characteristics and structural or environmental similarities of the organisms which are modified and evolved during the period of time. It is also known as life sciences evolve and genetic code provides more accurate information.

These evolutionary changes and will lead to certain organisms that are once thought to be unrelated organisms that may actually be related based on a genetic code. These codes have every small and accurate change that occurs and can also find out when these changes occured.

how many moles of silver nitrate are needed to produce 6.75 moles of copper (II) nitrate upon reacting with excess copper?

Answers

Answer:

13.50 moles of AgNO₃ are needed to produce 6.75 moles of Cu(NO₃)₂

Explanation:

We state the reactants:

AgNO₃

Cu

Then, the products are:

Cu(NO₃)₂

Ag

The reaction is:  2AgNO₃ + Cu  → 2Ag + Cu(NO₃)₂

Ratio is 1:2.

The copper is in excess, so the limiting reactant is the silver nitrate:

1 mol of Cu(NO₃)₂ is produced by 2 moles of AgNO₃

Then, 6.75 moles of copper (II) nitrate would be produced by, the double of moles

(6 75  . 2) /1  = 13.50 moles

How could we stop an asteroid that we know was going to hit Earth?


Pls help ASAP

Answers

Answer:

An object with a high mass close to the Earth could be sent out into a collision course with the asteroid, knocking it off course. When the asteroid is still far from the Earth, a means of deflecting the asteroid is to directly alter its momentum by colliding a spacecraft with the asteroid.

Hope it helps!!

Answer:

1. deflect it 2. grab it with a claw 3. blast it to smithereens

Explanation:

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What is The changes that happened in ptolameic era in ancient Egypt and why ? multiplication: 2x12=__________ What would be the first step in solving the equation 7/9x + 34 = 174? 2. What artist influenced the WPA Public Art Commission? The number of ions produced when a substance dissolves is always equal to the number of Adams in a chemical formula. What is incorrect about following statement? In the 1800s, an important motivation for "old" and "new" immigrants to settle in ethnic neighborhoods wasto learn how to speak English.to be near local public schools.to maintain their own cultures.O to work to adopt American culture. Hollywood Co. computed an overhead rate for machining costs ($1,500,000) of $15 per machine hour. Machining costs are driven by machine hours. The company produces two products, Chapel and Tower. Chapel requires 60,000 machine hours, while Tower requires 40,000 machine hours. Using activity-based costing, machining costs using machine hours to assign overhead to each product is what is the volume, in liters, of 5.500 mol of C3H3 gas at STP Which of the following choices is the best source of amino acids?O plants milkO animal fatsO water Question 1.:Which comparison is incorrect?-3 > -7-9 > 4-4 > -67 > 5________________________________Question 2:Which group of numbers is listed from least to greatest?-4, -6, -7, -8, -9-2, 3, 5, -8, 97, 4, -6, -7, -9-2, -1, 0, 4, 9 Two pet stores offer customers the opportunity to donate money, in dollar increments, to the local humane society at the register. The dot plots below show the amounts donated last week.The variability at each pet store is 1.4. The difference between the mode amount donated at each pet store is approximately how many times the variability?A. 3B. 4C. 2D. 5 1 According to Steven Kreis, what were two reasons the Roman Catholic Church was criticized at the beginningof the 16th century? [2] How do you stop a chewing problem? (When you have to chew smthn or you can't stay focused)I have one and I need to get rid of it. Can anyone help me? Drag each tile to the correct box.Match the lines from Chaucer's The Canterbury Tales to the characters they describe.And honoured everywhere for worthiness.At Alexandria, he, when it was won;Of courtliness, and stately manners took,And would be held worthy of reverenceIn wisps hung down such locks as he'd on head,But as to hood, for sport of it, he'd none,A lover and a lusty bachelor,With locks well curled, as if they'd laid in press.prioresssquireknightpardoner X2-6x+8=? Answer plzzzzzzzzzzzzzz It is device used to measure thee temperature of food/fish A table is sold hire purchase. The sales price consists of deposit of $306 and six monthly instalments of $60 each. How much does a customer pay for the table? 5x + 8 =33 what is the x What characteristic do thunderstorms, hurricanes, and tornadoes all share? A. They are all formed when cool and dry air rapidly rises. B. They are all formed when warm and moist air rapidly sinks. C. They are all formed when warm and moist air rapidly rises. D. They are all formed when cool and dry air rapidly sinks. what is phase change?