If 11.2 g of naphthalene, C10H8, is dissolved in 107.8 g of chloroform, CHCl3, what is the molality of the solution?

a. 0.811m
b. 0.0941 m
c.12.4 m
d. 0.0875 m
e. 0.0969m

Answers

Answer 1

Answer: 0.811m

Explanation: Molarity is the moles of solute present per kg of solvent.

Molar mass of C10H8 = . 128.17 g/mol

No. of moles = given mass/molar mass

11.2g C10H8 = 11.2/128.17 g/mol C10H8

= 0.0874 mol C10H8

NOW 107.8g solvent (chloroform) contains 0.0879 molecules (naphthalene)

1000g   ''    will contain (0.0879/107.8 x 1000) mole solute

= 0.811 mole

Molarity of the solution is 0.811 m (option A)


Related Questions

the specific heat capacity of titanium is 0.523j/g c what is the heat capacity of 2.3g of titanium

Answers

Answer:

1.2029 J/g.°C

Explanation:

Given data:

Specific heat capacity of titanium = 0.523 J/g.°C

Specific heat capacity of 2.3 gram of titanium = ?

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

1 g of titanium have 0.523 J/g.°C specific heat capacity

2.3  × 0.523 J/g.°C

1.2029 J/g.°C

PLEASE HELP I WILL GIVE 50 POINTS
Step 1: Create your poster.
On the poster board, draw a roller coaster track that starts with one large hill, followed by a valley, and then another, smaller hill.
Draw a cart in four different positions on the track, as outlined below.
First, draw the cart at the top of the first hill. Label it A.
Second, draw the cart going down the first hill, into the valley. Label it B. iii. Third, draw the cart at the bottom of the valley. Label it C.
iv. Last, draw the cart at the top of the second, smaller hill. Label it D.


c) Draw an energy pie chart above each of the cart’s four positions.
Choose your reference point for determining height.
Create a pie chart that accurately represents the ratio of the three forms of energy and label the sections of the pie Eg for gravitational potential energy, Ek for kinetic energy, and Eth for thermal energy.

Answers

Answer:

The one above me is correct! I used it. But of course I had to write a little different to the person's sentences and draw a little differently in my own way.

Explanation:

If somehow you can't open the PDF (the comment on top of my comment) here I took a screenshot of it, if you need it! Good luck everyone :D

WHo Plays adopt me on Rob.lox tell me what pets you have and tell me your gender

Answers

Explanation:

I have a dog in my dog is a girl

Answer:

me

Explanation:

I'm a girl and I have a RIDE skele-rex and a ride cerberus and a n f r GRIFFIN and a f r gold rat and a normal unicorn a RIDE kitsune

A molecule has sp3 hybridization with 1 lone pair. The electron pair geometry of this molecule is:________ . The geometry of this molecule is:___________ This molecule will have approximate bond angles of (If more than one bond angle is possible, separate each with a space.):______

Answers

Answer:

Tetrahedral

Trigonal pyramidal

less than 109.5°

Explanation:

If a molecule has a hybridization of sp3 it must have four electron domains which corresponds to a tetrahedral geometry.

Now we were told that the molecule also has one lone pair. It means that one out of the four electron domains is composed of a lone pair. Thus the molecular geometry will be trigonal pyramidal (e.g NH3).

Recall that lone pairs usually decrease the bond angle to a value less than the expected value for that particular electron domain geometry.

The expected bond angle for a tetrahedral geometry is 109.5° but that of the trigonal planar geometry is less than this.

Identify an element that is NOT in its standard state.
Choose the one alternative that best completes the statement or answers the question.
A) N2(g)
B) Xe(g)
C) Ca(s)
D) N(g)

Answers

Explanation:

Xenon is a gas in its standard state

Calcium is a solid in its standard state

Nitrogen is a gas in its standard state

I am assuming that N2 is a isotope of nitrogen, not sure which but by the process of elimination I think that is the answer

Which element has three electron shells and 4 valence electrons?


Silicon


Carbon


Gallium


Argon

Answers

Answer: Silicon

Explanation:

For something to have 4 valence electrons, it must be in the 14th column, which elimates gallium and argon for the possible answers. For somethign to have 3 electron shells, it must be in the third row of the periodic table which means the answer is silicon.

Answer:

Gallium

Explanation:

I believe this is the answer if not then the only other option is boron but anyways the answer is Gallium

Samantha AS
Which of the following compounds is ionic but yet it is expected to
contain covalent bonds as well in the form of a polyatomic ion?

NH3

KBr

CO2

NaF

Fe(NO2)3

Answers

Answer:

Fe(NO2)3

Explanation:

A poly atomic ion is an ion that contains more than one atom.

If we look at all the compounds that have been mentioned among the options; KBr and NaF are both ionic but do not contain any covalent poly atomic ion.

However, Fe(NO2)3  contains NO2^+ which is a poly atomic ion that contains the covalent bond.

Derive an expression for the molar mass of a gas starting with its density?

Answers

Answer:

The relationships between molar mass and density for a monoatomic gas can be easy.  

The Ideal Gas Law, PV = nRT can be arranged so that n moles equals the mass/molar mass of the gas to become,

PV =  

M

mRT

​  

 

where m is the mass and M is the molar mass.

M =  

PV

mRT

​  

, if you hold the temperature of the gas constant the equation reduces to the Boyle's law or  

PV

m

​  

 

The mass will be constant assuming the container is closed and so the gas cannot be escaped so, PV will be constant.  

D =  

V

m

​  

 and M =  

PV

mRT

​  

 

M =  

P

DRT

​  

 

The higher the density of the gas the higher the molar mass and vice versa.

Explanation:

hich of the following best describes a person doing science?

A.
Dominick uses a computer to do his math homework.
B.
Lindsay measures the sizes of the craters on the Moon.
C.
Isabel invents a new kind of doorknob.
D.
Murray randomly predicts the result of a coin toss.

Answers

Answer:

I think it is answer B. what grade are you in? im in 7th.

Explanation:

11. Which of the following equations shows a
synthesis reaction?
A
B
C
D

Answers

Answer: D

Explanation:

How many kJ of heat are needed to completely melt 1.70 moles of H2O, given that the water is at its melting point? The heat of fusion for water is 6.02 kJ/mole.

Answers

Answer:

1.70×6.02=6.4414

Explanation:

it would be times

10.2234 kJ of heat is needed to completely melt 1.70 moles of H2O, given that the water is at its melting point and the heat of fusion for water is 6.02 kJ/mole.

What is latent heat?

The term "latent heat" refers to the heat energy that a substance retains when its phase changes during a specific process. The latent heat of evaporation, which occurs when a liquid absorbs heat from an external source at its boiling point, is one of many types of latent heat.

Similarly, the latent heat of fusion is used when any substance melt at its melting point to change the liquid phase of that substance.

As given in the problem, The heat of fusion for water is 6.02 kJ/mole. This means 6.02 kJ heat is needed to melt 1 mole of ice into water

Then the heat are needed to completely melt 1.70 moles of H2O,

Heat  = 1.70 moles ×6.02 kJ/mole

Heat = 10.2234 kJ

Thus, the heat needed to completely melt 1.70 moles of H2O is 10.2234 kJ

Learn more about Latent heat from here

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#SPJ2

The balanced half-reaction in which chlorine gas is reduced to the aqueous chloride ion is a ________ process. one-electron two-electron four-electron three-electron six-electron

Answers

Answer:

Two-electron.

Explanation:

Hello!

In this case, since the half-reaction by which chlorine is reduced to aqueous chloride ion is:

[tex]Cl^0_2\rightarrow 2Cl^-[/tex]

We can see each chlorine undergo a decrease of electrons by 1, it means that, since there are two chlorine atoms undergoing an electron decrease, we write:

[tex]Cl^0_2+2e^-\rightarrow 2Cl^-[/tex]

Which means this is a two-electron process.

Best regards!

What are the other properties of pure substance

Answers

Answer:

Characteristics and Properties Of Pure Substances

Pure substances are mostly homogeneous in nature containing only one type of atoms or molecules. These substances mainly have a constant or uniform composition throughout. The substances have fixed boiling and melting points.

Explanation:

they have fixed boiling and melting

The boiling point of an aqueous solution is 101.54 ∘C. What is the freezing point

Answers

Answer:

101.54 .C.

Explanation:

What volume of hydrogen gas at STP will be produced from 36.7 g of magnesium reacting with an excess amount of hydrochloric acid?

Answers

Answer:

V = 34.3 L

Explanation:

Given data:

Volume of hydrogen produced = ?

Mass of magnesium = 36.7 g

Temperature and pressure = standard

Solution:

Mg + 2HCl       →   MgCl₂ + H₂

Number of moles of magnesium:

Number of moles = mass/molar mass

Number of moles = 36.7 g/ 24 g/mol

Number of moles = 1.53 mol

Now we will compare the moles of magnesium with hydrogen.

                         Mg           :          H₂

                          1              :           1

                         1.53          :          1.53

Number of moles of hydrogen produced = 1.53 mol

Volume of hydrogen:

PV = nRT

V = nRT / P

V = 1.53 mol × 0.0821 atm.L/mol.K × 273 K/ 1 atm

V = 34.3 L

4. Which of the following demonstrates an organ providing a force?

A. The kidney filters waste from blood.

B. The heart contracts and expands to move blood.

C. he eye transmits information to the brain

D. The skin protects other organs from damage.​

Answers

Answer:

Um uhhhh um 4d

Explanation:


If 42 grams of carbon and 52 grams of oxygen are used, how many grams of CO2 will be produced (Hint: find the
limiting reactant first). SHOW WORK
C + O2 + CO2

Answers

Answer:

71.5g

Explanation:

The reaction equation is given as:

               C  +  O₂  →  CO₂

Mass of C = 42g

Mass of O₂  = 52g

Unknown:

Mass of CO₂ produced  = ?

Solution

Now to solve this problem, we have to find limiting reactant which is the one given in short supply in this reaction.

 The extent of the reaction is controlled by this reactant.

Find the number of moles of the given species;

 Number of moles  = [tex]\frac{mass}{molar mass}[/tex]

      Number of moles of C  = [tex]\frac{42}{12}[/tex]   = 3.5mol

     Number of moles of O₂   = [tex]\frac{52}{32}[/tex]   = 1.63mol

Now;

   From the balanced reaction equation;

           1 mole of C reacted with 1 mole of O₂

We see that C is in excess and O₂ is the limiting reactant.

            1 mole of O₂ will produce 1 mole of CO₂

 So;      1.63mole of O₂ will produce 1.63 mole of CO₂

Mass of CO₂ = number of moles x molar mass

       Molar mass of CO₂ = 44g/mol

Mass of CO₂ = 1.63 x 44 = 71.5g

6.Which of the following is NOT true about the lens?

Answers

the answer is A btw

The following statement which is NOT true about the lens is:

A. It sends light to the optic nerve

The lens is a piece of glass which  is used for the dispersal or refraction of light and is used to focus light onto the retina of the eye.

As a result of this, the lens is responsible for refracting of light, focusing of light and it is transparent. However, it does not send light to the optic nerve.

Therefore, the correct answer is option A

Read more here:

https://brainly.com/question/23730298

What do we call ingredients in a chemical reaction

Answers

Answer:

Reactants or Factors

Explanation:

make the product

25 grams of radon-222 remains after 15.28 days. How much radon was in the original sample? Write an equation for the decay of radon-222.

Answers

Answer:

half-life = 3.8 days

total time of decay = 15.2 days

initial amount = 100. g

number of half-lives past: 15.2/3.8 = 4 half-lives

4 half-lives = 1/16 remains

100. g x 1/16 = 6.25 g

Chemistry work here. Please help as soon as possible. I have allot of questions that needs to be answered. Can someone do it for me?

Answers

Answer:

I dont know about the yield but I think mno2 is the limiting reactant

suppose 2.5g of compound a and 3.5g of compound b are consumed in a reaction that produces only one product compound c

Answers

Answer:

Mass of compound c = 6 g

Explanation:

Given:

Mass of compound a = 2.5 g

Mass of compound b = 3.5 g

Find:

Mass of compound c

Computation:

According to Law of conservation of mass

Mass of compound a + Mass of compound b = Mass of compound c

Mass of compound c = 2.5 + 3.5

Mass of compound c = 6 g

You have 0.500 L of an 0.250 M acetate buffer solution (i.e. [HC₂H₃O₂] + [C₂H₃O₂⁻] = 0.250 M) at pH 3.50. How many mL of 1.000 M NaOH must you add in order to change the pH to 5.07? Acetic acid has a pKa of 4.74.

Answers

Answer:

80mL of 1.00M NaOH

Explanation:

Using H-H equation, we can determine oH of a buffer as acetate buffer. First, we need to determine amount of acetate ion and acetic acid at pH 3.50 and 5.07. Then, with the reaction of NaOH with acetic acid we can find the amount of 1.00M NaOH that must be added:

At pH 3.50:

pH = pka + log [C₂H₃O₂⁻] / [HC₂H₃O₂]

3.50 = 4.74 + log [C₂H₃O₂⁻] / [HC₂H₃O₂]

0.057544 = [C₂H₃O₂⁻] / [HC₂H₃O₂] (1)

Using and replacing in (1):

[HC₂H₃O₂] + [C₂H₃O₂⁻] = 0.250 M

[HC₂H₃O₂] + 0.057544[HC₂H₃O₂] = 0.250 M

1.057544 [HC₂H₃O₂] = 0.250M

[HC₂H₃O₂] = 0.2364M * 0.500L = 0.1182 moles of acetic acid at first pH

At pH 5.07:

pH = pka + log [C₂H₃O₂⁻] / [HC₂H₃O₂]

5.07 = 4.74 + log [C₂H₃O₂⁻] / [HC₂H₃O₂]

2.13796= [C₂H₃O₂⁻] / [HC₂H₃O₂] (1)

Using and replacing in (1):

[HC₂H₃O₂] + 2.13796[HC₂H₃O₂] = 0.250 M

3.13796 [HC₂H₃O₂] = 0.250M

[HC₂H₃O₂] = 0.07967M * 0.500L = 0.0398 moles of acetic acid at first pH

Now, NaOH reacts with HC₂H₃O₂ as follows:

NaOH + HC₂H₃O₂ → NaC₂H₃O₂ + H₂O

As moles of acetic acid decreases from 0,1198 moles - 0,0398 moles = 0,08 moles of acetic acid are consumed = 0,08 moles of NaOH

0,08 mol NaOH * (1L / 1mol) = 0,08L of 1.00M NaOH =

80mL of 1.00M NaOH

The original solution used to make the solutions for the standard curve was prepared by dissolving 2.60g of CoCl2 (molar mass 130.g/mol ) in enough water to make 100.mL of solution. What is the molar concentration of the solution?

Answers

Answer:

0.200 M

Explanation:

Step 1: Given data

Mass of CoCl₂ (m): 2.60 gMolar mass of CoCl₂ (M): 130 g/molVolume of solution (V): 100 mL

Step 2: Calculate the moles (n) of CoCl₂ (solute)

We will use the following expression.

n = m/M

n = 2.60 g/(130 g/mol)

n = 0.0200 mol

Step 3: Convert "V" to liters

We will use the conversion factor 1 L = 1000 mL.

100 mL × 1 L/1000 mL = 0.100 L

Step 4: Calculate the molarity of CoCl₂

We will use the definition of molarity.

[CoCl₂] = n/V(L)

[CoCl₂] = 0.0200 mol/0.100 L

[CoCl₂] = 0.200 M

The molar concentration of the solution is 0.2 M.

First, we must calculate the number of moles of CoCl2 as follows;

Number of moles = mass/molar mass

mass = 2.60g

Molar mass =  130.g/mol

Number of moles = 2.60g/ 130.g/mol = 0.02 moles

Molarity of solution = Number of moles/volume of solution in liters

Volume of solution = 100.mL or 0.1 L

Molarity of solution = 0.02 moles/0.1 L

Molarity of solution = 0.2 M

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Element Z has 2 isotopes. A sample of element Z contains 19% Z234 and 81% Z236. What is the average atomic mass of the element Z?

Answers

Answer:

Wt Avg of the two isotopes = 235.62 amu

Explanation:

Given:

                                    abundance

Isotope     %      fractional     mass (amu)         Wt. Avg. Contributions

Z234        19%        0.19              234                (0.19)(234) = 44.46 amu

Z236        81%        0.81              236                (0.81)(236) = 191.16 amu

Collective Wt. Avg. of all isotopes = ∑ Wt. Avg. Contributions

= 44.46 amu + 191.16 amu = 235.62 amu

d) hydrogen and sulfur
Formed

Answers

Answer:

At high temperatures or in the presence of catalysts, sulfur dioxide reacts with hydrogen sulfide to form elemental sulfur and water. This reaction is exploited in the Claus process, an important industrial method to dispose of hydrogen sulfide.

If a stick of dynamite explodes, the
chemical energy changes into what?______________
potential energy, air and clouds
potential energy and physical
energy
kinetic energy, heat and light
Kinetic energy and precipitation​

Answers

Answer:

kinetic energy, heat and light i'm pretty sure

What is the formula for Nickel (II) Bisulfate?​

Answers

Answer:

[tex]NiHSO_{4}[/tex]

Explanation:

We're using nickel with a charge of 2, as indicated by the "(II)" in the name, and bisulfate refers to HSO[tex]_{4}[/tex], which has a charge of 2-, so they are in a 1:1 ratio.

Mechanical weathering does not change a rock’s
A
shape.

B
size.

C
appearance.

D
composition.

Answers

Answer:

C

Explanation:

Answer:

B: Size

Explanation: It can break it into smaller pieces but not change its composition.

If the mass of an object on Earth is 25 kg, what is its weight?

Answers

Answer:

250 Newtons.

Explanation:

Weight is a force and the Second Law of Newton can be used to figure out the Force ( weight) of this mass. Since F = ma, and 'a' on Earth is the acceleration due to freefall at 10 m/s^2 ( really 9.8 m/s^2- so your teacher may want your answer as 245 N), you multiply your mass ( 25g ) and your acceleration on Earth and you get 250 N.

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