A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol

Answers

Answer 1

Answer:

The correct answer is 146 g/mol

Explanation:

Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:

ΔTf = Kf x m

Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:

ΔTf = 1.02ºC

Kf = 5.12ºC/m

From this, we can calculate the molality:

m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m

The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:

0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute

There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:

molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol

Therefore, the molar mass of the compound is 146 g/mol


Related Questions

When does carbon dioxide absorb the most heat energy?
during freezing
during deposition
during sublimation
during condensation

Answers

During sublimation

This has been posted on here before so you could’ve searched it lol.

Best of luck :))

Answer:

during sublimation

Explanation:

just took the test

What types of materials are better at absorbing energy from radiation?

Answers

Answer:

Explanation:

Materials are clothes and heavy rope

How to separate given mixture?

Answers

Answer:

Chromatography involves solvent separation on a solid medium.

Distillation takes advantage of differences in boiling points.

Evaporation removes a liquid from a solution to leave a solid material.

Filtration separates solids of different sizes.

Explanation:

Which option BEST explains how thermal equilibrium interacts with heat transfer between particles?


a

Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.

b

Thermal equilibrium always transfers energy from the hotter object to the colder one, and increases the energy and speed of moving particles in both objects as the temperature decreases.

c

Thermal equilibrium helps the transfer of energy between the particles of some materials better than others, but always stops the transfer of energy in materials like plastic and wood.

d

Thermal equilibrium quickly transfers energy back to the particles of the object that was originally hotter, and requires that the particles in both objects have reached equal energy and density.

Answers

Answer:

Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.

Explanation:

a. The transfer of energy occurs until both objects reach thermal equilibrium. But particles are always moving and crashing with each other. TRUE.

b. The heat transfer occurs from the hotter object to the colder one but moving of particles descreases with temperature decreasing. FALSE.

c. Plastic and wood have a poor quality to transfer energy but there is no material that "stops" perfectly the transfer of energy. FALSE.

d. The heat is transferred from the particles of the hotter object to the particles of the colder one. FALSE

Calculate the following quantity: molarity of a solution prepared by diluting 49.16 mL of 0.0270 M ammonium sulfate to 525.00 mL.

Answers

Answer:

2.528x10⁻³M

Explanation:

Molarity is an unit of concentration used in chemistry. Is defined as the moles of solute per liter of solution.

To find the molarity of the solution we need to determine the moles of ammonium sulfate present in the initial 49.16mL solution and, with total volume, we can find the molarity, thus:

Moles ammonium sulfate:

49.16mL = 0.04916L * (0.0270 moles / L) =

1.327x10⁻³moles ammonium sulfate

These moles are present in 525.0mL = 0.525L. Thus, molarity of the solution will be:

1.327x10⁻³moles ammonium sulfate / 0.525L =

2.528x10⁻³M

A chemist decomposes samples of several compounds; the masses of their constituent elements are listed. Calculate the empirical formula for each compound.

a. 1.245 g Ni, 5.381 g I,
b. 2.677 g Ba, 3.115 g Br,
c. 2.128 g Be, 7.557 g S, 15.107 g

Answers

Answer:

you can see the empirical formula at the pic

The empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.

What is empirical formula?

Empirical formula of a compound is defined as the simplest whole number ratio of atoms present in a compound.

(a) 1.245 g Ni : 5.381 g I

Mole of Ni ; Mole of I = 1.245/59 : 5.381/127 = 0.02 : 0.04 = 1:2

So the formula is NiI2

(b) 2.677 g Ba : 3.115 g Br

Mole of Ba : Mole of Br = 2.677/137 : 3.115/60 = 0.019 : 0.038

= 0.02 : 0.04 = 1:2

So the formula is BaBr2

(c) 2.128 g Be : 7.557 g S

Mole of Be : Mole of S = 2.128/9 : 7.557/32 = 0.2 : 0.2 = 1:1

So the formula is BeS

Thus, empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.

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which of the following Ph levels would indicate the weakest base?

15

8

6

2​

Answers

Answer:

8

Explanation:

7 is neutral any anything above it is basic and anything below is acidic which means 8 would be the lowest base

Answer:

The pH of a weak base falls somewhere between 7 and 10.

Explanation:

Like weak acids, weak bases do not undergo complete dissociation; instead, their ionization is a two-way reaction with a definite equilibrium point

A sample of propane, C3H8, contains 13.8 moles of carbon atoms. How many total moles of atoms does the sample contain

Answers

Answer:

[tex]Total = 50.6\ moles[/tex]

Explanation:

Given

[tex]Propane = C_3H_8[/tex]

Represent Carbon with C and Hydrogen with H

[tex]C = 13.8[/tex]

Required

Determine the total moles

First, we need to represent propane as a ratio

[tex]C_3H_8[/tex] implies

[tex]C:H = 3:8[/tex]

So, we're to first solve for H when [tex]C = 13.8[/tex]

Substitute 13.8 for C

[tex]13.8 : H = 3 : 8[/tex]

Convert to fraction

[tex]\frac{13.8}{H} = \frac{3}{8}[/tex]

Cross Multiply

[tex]3 * H = 13.8 * 8[/tex]

[tex]3 H = 110.4[/tex]

Solve for H

[tex]H = 110.4/3[/tex]

[tex]H = 36.8[/tex]

So, when

[tex]C = 13.8[/tex]

[tex]H = 36.8[/tex]

[tex]Total = C + H[/tex]

[tex]Total = 13.8 + 36.8[/tex]

[tex]Total = 50.6\ moles[/tex]

If 5.00g of iron metal is reacted with 0.950g of Cl2 gas, how many grams of ferric chloride (FeCl3) will form?

Answers

Answer:

1.45g of FeCl3

Explanation:

The equation of the reaction is given as;

2Fe + 3Cl2 --> 2FeCl3

2 mol of Fe reracts with 3 mol of Cl2 to form 2 mol of FeCl3

Upon converting to mass using;

Mass = Number of moles * Molar mass

( 2 * 55.85 = 111.7g ) of Fe reacts with ( 3 * 71 = 213g ) of Cl2 to form ( 2 * 162.2 = 324.4g) of FeCl3

Cl2 is the limiting reactant as it determines how much of FeCl3 is formed

213g of Cl2 = 324.4g of FeCl3

0.950g of Cl2 = x

x = (0.950 * 324.4 ) / 213

x = 1.45g of FeCl3

If 1.4434 moles of H2O are produced, how many moles of N2 will also be produced?

Answers

Answer:

1 gram of N2 is equal to 0.035697202053303 mole. i dont know the rest but intried to help

. hopefully this will give you someone else a starting point. goodluck

On average, about ____________ of incoming solar radiation is reflected back to space.
A 50%
B 30%
C 20%
D 10%

Answers

I believe it B 30% hope that helps
I think it’s B I’m not sure sorry if it’s wrong

2.
(3x – 4y = -10
(6x + 3y = –42
SOLUTION:

Answers

Answer:

Is like for solving for the solution for both equations??

What is the frequency of a wave having 4.90 x 10 -12 J of energy?

Answers

Answer:

The answer is

[tex] \huge 7.40 \times {10}^{21} Hz[/tex]

Explanation:

To find the frequency of the wave we use the formula

[tex]f = \frac{E}{h} \\ [/tex]

where

E is the energy

f is the frequency

h is the Planck's constant which is

6.626 × 10-³⁴ Js

From the question

E = 4.90 × 10-¹² J

So we have

[tex]f = \frac{4.90 \times {10}^{ - 12} }{6.626 \times {10}^{ - 34} } \\ [/tex]

We have the final answer as

[tex]7.40 \times {10}^{21} \: \: Hz[/tex]

Hope this helps you

how can you tell where sugar enters the blood stream


please help asap​

Answers

Answer:

Sugar can't enter cells directly , so when blood sugar level rises, ... signal for the release of insulin into the bloodstream.

Explanation:

yes when the sugar enter the bloodstream it may slowly slowly effect in your body and it may causes diabetes

as a student,living in the philippines considered to be part of the global south,how are you going to compete and survive challenges of globalization?​

Answers

Answer:

Natural Selection

Explanation:

Which is a chemical property of milk
A. Milk has a ph ranging from 6.4 to 6.8
B. Milk spoils when left unrefrigerated
C. Milk boils at about 212F
D. Milk curdles when mixed with vinegar

Answers

Answer:

C. Milk boils at about 212F

Explanation:

The principal constituents of milk are water, fat, proteins, lactose (milk sugar) and minerals (salts). Milk also contains trace amounts of other substances such as pigments, enzymes, vitamins, phospholipids (substances with fatlike properties), and gases.


C is the answer milk boils about 212F

Which of the following substances would have the greatest ductility?
A. Fe(s)
B. SiO2(s)
C. C(s)
D. NaCl(s)

Answers

Fe(s) would have the greatest ductility.

What is ductility?

Ductility is the capability of a fabric to be drawn or plastically deformed without fracture. it's far therefore a demonstration of how 'gentle' or malleable the fabric is. The ductility of steel varies relying on the sorts and levels of alloying factors gift.

What are malleability and ductility?

Ductility is the property of metallic associated with the capability to be stretched into twine without breaking. Malleability is the assets of metallic associated with the ability to be hammered into thin sheets without breaking. The outside force or strain is tensile pressure.

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One way to represent a substance is with a chemical formula. In the formula CO2, what do the symbols Cand o refer to?

Answers

Answer:

C is for carbon and O is for oxygen

C reference carbon and O reference oxygen

Is air a homogeneous heterogeneous mixture or substance

Answers

Answer:

look at the explanation

Explanation:

The air that you breathe is a homogeneous mixture of oxygen, nitrogen, argon, and carbon dioxide, along with other elements in smaller amounts. Because each layer of the Earth's atmosphere has a different density, each layer of air is its own homogeneous mixture.

Hope this helps. :)

10. Which of the following is NOT correctly matched?

A. Salt: Na and C: Element

B. Water: H and O: Corapound

C. Carbon dioxside: C and O: Compound

D. Magnesium chloride: Mg and C: Compound​

Answers

Answer:

A. because salt : Na and Cl, not C

Pls help, and fast plsssssssss

Answers

Answer:

The cell on the left is animal, The cell on the right is a plant cell.

Explanation:

1: cell membrane

2: chloroplast

3: cell wall

4: vacuole

5: mitochondria

6:nucleus

7: lysosome

8: cytoplasm

Things to remember, only plant cells have cell walls. Plant cells are the only ones that have chloroplast.

since there is a answer already imma just take sum points

If 25.6 mL isopropyl alcohol fully decomposes, what mass of H2 is formed? The density of isopropyl alcohol is 0.785 g/mL. g

Answers

Answer:

The correct answer is 0.67 g H₂

Explanation:

Isopropyl alcohol (C₃H₇OH) can decompose to give acetone (C₂H₆OH) and hydrogen gas (H₂) according to the following chemical equation:

C₃H₇OH (g) ⇒ C₂H₆CO(g) + H₂(g)

We can calculate the initial mass of isopropyl alcohol from the density and volume data:

density = m/V = 0.785 g/mL

⇒ m = density x V = 0.785 g/mL x 25.6 mL = 20.096 g C₃H₇OH

According to the chemical equation 1 mol of C₃H₇OH gives 1 mol H₂. The molar mass of C₃H₇OH is:

molar mass C₃H₇OH = (12 g/mol x 3) + (1 g/mol x 7) + 16 g/mol + 1 g/mol = 60 g/mol

molar mass H₂ = 1 g/mol x 2 = 2 g/mol

So, we obtain: 2 g H₂ from 60 g C₃H₇OH. We multiply this stoichiometric ratio (2 g H₂/60 g C₃H₇OH) by the initial mass of C₃H₇OH to obtain the mass of H₂ is formed:

20.096 g C₃H₇OH x (2 g H₂/60 g C₃H₇OH) = 0.6698 g ≅ 0.67 g H₂

How do the test variables (independent variables) and outcome variables (dependent variables) in an experiment compare? A. The test variables (independent variables) and outcome variables (dependent variables) are the same things. B. The test variable (independent variable) controls the outcome variable (dependent variable). C. The test variable (independent variable) and outcome variable (dependent variable) have no affect on each other. D. The outcome variable (dependent variable) controls the test variable (independent variable).

Answers

Answer:

I'm on the exact same queston

Answer:

The test variable (independent variable) controls the outcome variable (dependent variable)

Explanation:

its right on study island

for the following reaction, provide the missing information

Answers

Answer:

19. Option B. ⁰₋₁B

20. Option D. ²¹⁰₈₄Po

Explanation:

19. ²²⁸₈₈Ra —> ²²⁸₈₉Ac + ʸₓZ

Thus, we can determine ʸₓZ as follow:

228 = 228 + y

Collect like terms

228 – 228 = y

y = 0

88 = 89 + x

Collect like terms

88 – 89 = x

x = –1

Thus,

ʸ ₓZ => ⁰₋₁Z => ⁰₋₁B

²²⁸₈₈Ra —> ²²⁸₈₉Ac + ʸₓZ

²²⁸₈₈Ra —> ²²⁸₈₉Ac + ⁰₋₁B

20. ᵘᵥX —> ²⁰⁶₈₂Pb + ⁴₂He

Thus, we can determine ᵘᵥX as follow:

u = 206 + 4

u = 210

v = 82 + 2

v = 84

Thus,

ᵘᵥX => ²¹⁰₈₄X => ²¹⁰₈₄Po

ᵘᵥX —> ²⁰⁶₈₂Pb + ⁴₂He

²¹⁰₈₄Po —> ²⁰⁶₈₂Pb + ⁴₂He

Define waves in your own words.

Answers

Answer:

Waves is the disturbance or variation that transfer energy from one location to other

Answer:

this is not in my words but i think this will help

(put some of the words you would use in this)

Explanation:

Transverse waves are always characterized by particle motion being perpendicular to wave motion. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves. ... Longitudinal waves are always characterized by particle motion being parallel to wave motion.

hope i helped

The empirical formula of CBr2 has a molar mass of 515.46 g/mol. What is the molecular formula of this
compound

Answers

Answer:

C3Br6

Explanation:

C= (1 X 12.011) = 12.011

Br= (2 X 79.904)= 159.808

159.808+12.011 = 171.819

515.46 divided by 171.819 = 3.00

so you mulitpy CBr2 by 3 which gives you C3Br6

4.5 tons → lbs
4.5 tons equals how many pounds

Answers

Answer:

9000 pounds

Explanation:

9000 pounds

Answer: 9000 lbs.

Explanation: 4.5 tons = 9000 pounds.

Name the following ionic compound: Ba(OH)2*2H2O​

Answers

Barium hydroxide is a chemical compound with the chemical formula Ba(OH)2(H2O)x. The monohydrate (x =1), known as baryta or baryta-water, is one of the principal compounds of barium.

Metals typically lose electrons to complete their octet in a reaction with non-metals, whereas non-metals typically acquire electrons to complete their octet. Ionic compounds are typically formed via reactions between metals and nonmetals. The given compound barium hydroxide is ionic.

Ions with the opposite charge are carefully packed together to form crystalline solids. Ionic compounds typically result from reactions between metals and non-metals. The electrostatic interaction between the positive and negative ions holds ionic solids together.

Baryta, commonly known as barium hydroxide, has the chemical formula Ba(OH)₂. It is an odorless, clear-white powder. It has a toxic disposition. It is ionic in nature, with two hydroxide ions per molecule of barium hydroxide (Ba(OH)₂ in an aqueous solution an example.

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In which atmospheric layer is the ozone layer?
A.troposphere
B.mesosphere
C.stratosphere
D.thermosphere

Answers

Answer:

stratosphere

Explanation:

contains a high concentration of ozone in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.

Answer:

stratosphere

Explanation: Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface. Ozone is a molecule that contains three oxygen atoms.

Helpppp!!!!! Please help me

Answers

Answer:

10.)Weight and mass are different because only weight describes the force of gravity on an object.

11.)On a planet with more mass than earth your weight would be higher because greater gravitational pull.

On a planet with less mass than earth your weight would be less because of the lower gravitational pull.

Explanation:

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