1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
alexdok [17]
3 years ago
7

A solution is prepared by mixing 50.0 mL toluene (C6H5CH3 d=0.867 g/mL) with 125 mL Benzene (C6H6 d=0.874 g/mL). Assuming that t

he volumes add upon mixing, calculate the mass percent, mole fraction, molality, and molarity of the toluene.
Chemistry
1 answer:
Tatiana [17]3 years ago
4 0

Answer:

mass % = 28.4%

mole fraction = 0.252

molality = 3.08 molal

molarity = 2.69 M

Explanation:

Step 1: Data given

Volume of toluene = 50.0 mL = 0.05 L

Density toluene = 0.867 g/mL

Molar mass toluene = 92.14 g/mol

Volume of benzene = 125 mL = 0.125 L

Density benzene = 0.874 g/mL

Molar mass benzene = 78.11 g/mol

Step 2: Calculate masses

Mass = density * volume

Mass toluene = 50.0 mL * 0.867 g/mL = 43.35 g

Mass benzene = 125 mL * 0.874 g/mL = 109.25 g

Step 3: Calculate number of moles

Moles = mass / molar mass

Moles toluene = 43.35 grams /92.14 g/mol = 0.470 5 moles

Moles benzene = 109.25 grams / 78.11 g/mol = 1.399 moles

Step 4: Calculate molarity of toluene

Molarity = moles / volume

Molarity toluene = 0.4705 moles / 0.175 L = 2.69 M

Step 5: Calculate mass % of toluene

Mass % = (43.35 grams / (43.35 + 109.25) )*100 % = 28.4 %

Step 6: Calculate mole fraction of toluene

Mole fraction toluene = Moles toluene / total number of moles

Mole fraction toluene = 0.4705 / (0.4705 + 1.399) = 0.252

Step 7: Molality of toluene

Molality = number of moles / mass

Molality of toluene = 0.4705 moles / (0.04335 + 0.10925)

Molality of toluene = 3.08 molal

You might be interested in
Gasoline is a mixture of hydrocarbons, a major component of which is octane, CH3CH2CH2CH2CH2CH2CH2CH3. Octane has a vapor pressu
Nitella [24]

Answer:

\Delta \:H_{vap}=40383.88\ J/mol

Explanation:

The expression for Clausius-Clapeyron Equation is shown below as:

\ln P = \dfrac{-\Delta{H_{vap}}}{RT} + c

Where,  

P is the vapor pressure

ΔHvap  is the Enthalpy of Vaporization

R is the gas constant (8.314×10⁻³ kJ /mol K)

c is the constant.

For two situations and phases, the equation becomes:

\ln \left( \dfrac{P_1}{P_2} \right) = \dfrac{\Delta H_{vap}}{R} \left( \dfrac{1}{T_2}- \dfrac{1}{T_1} \right)

Given:

P_1 = 13.95 torr

P_2 = 144.78 torr

T_1 = 25°C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15  

So,  

T = (25 + 273.15) K = 298.15 K

T_1 = 298.15 K

T_2 = 75°C  = 348.15 K

So,

\ln \:\left(\:\frac{13.95}{144.78}\right)\:=\:\frac{\Delta \:H_{vap}}{8.314}\:\left(\:\frac{1}{348.15}-\:\frac{1}{298.15}\:\right)

\Delta \:H_{vap}=\ln \left(\frac{13.95}{144.78}\right)\frac{8.314}{\left(\frac{1}{348.15}-\frac{1}{298.15}\right)}

\Delta \:H_{vap}=\frac{8.314}{\frac{1}{348.15}-\frac{1}{298.15}}\left(\ln \left(13.95\right)-\ln \left(144.78\right)\right)

\Delta \:H_{vap}=\left(-\frac{863000.86966\dots }{50}\right)\left(\ln \left(13.95\right)-\ln \left(144.78\right)\right)

\Delta \:H_{vap}=40383.88\ J/mol

4 0
3 years ago
Help me please i dont understand
Lelechka [254]

Answer:

1. Dissolving powder in milk - Chemical

  - It is chemical because the milk has changed on a molecular level

2. Toasting bread - Chemical

   - It is chemical because adding heat to the bread cooks it, therefore

     changing it on a molecular level

3. Melting cheese - Physical

   - It is physical because the physical appearance was the only change

4. Slicing apples or bannanas - Physical

   - It is physical because the physical appearance was the only change

5. Frying an egg - Chemical

   - It is chemical because new particles were formed

6. Milk souring - Chemical

   -  It is chemical because it is forming a new product (lactic acid)

Explanation:

Physical Change occurs when the particles of a substance become rearranged, but do not change into different particles.  

Chemical change occurs when a new substance is formed. This process is irreversable.

6 0
2 years ago
Read 2 more answers
An alkene X undergoes ozonolysis and gives two compounds Y and Z of molecular formula CaHO. Y and Z are functional isomers of ea
lys-0071 [83]

i. The given compound X is 2-methyl pent-2-ene. When it is reacted with ozone it forms an ozonide in the first step. In the second step the reduce to forms acetone and propanal.

ii. The structural formula of Y is CH_3-CO-CH_3 and Z is CH_3-CH_2-CHO.

iii. Alkenes, upon catalytic hydrogenation, form alkanes. This will occur in the presence of Nickel as the catalyst.

iv. The process of ozonolysis is useful in the field of pharmaceutics.

v. The test of unsaturation can be performed by passing a compound through Bromine water.

<h3>What is ozonolysis?</h3>

Ozonolysis is a reaction used in organic chemistry to determine the position of a carbon-carbon double bond in unsaturated compounds.

i. The given alkene X, that is subject to ozonolysis would be 2-methyl-2-pentene. Upon exposure to ozone, an ozonide is initially formed, after which it is broken down into 2 products - acetone and propanal, both with the molecular formula C₃H₆O.

The given compound X is 2-methyl pent-2-ene. When it is reacted with ozone it forms an ozonide in the first step. In the second step the reduce to forms acetone and propanal.

ii. The formulas of Y is CH_3-CO-CH_3 and Z is CH_3-CH_2-CHO. They are functional isomers as they have the same molecular formula but different functional groups - ketone and aldehyde.

iii. When alkenes undergo catalytic hydrogenation, they form alkanes, X will form 2 methyl petane on reaction with hydrogen gas in presence of Ni.

iv. The ozonolysis is used for the industrial-scale synthesis of pharmaceuticals.

v. The unsaturation of compound X can be proved by the bromine water test. As on reaction with it, the brown colour of bromine water becomes colourless due to the formation of dibromo alkane.

Learn more about the ozonolysis here:

brainly.com/question/14356308

#SPJ1

5 0
2 years ago
What is the molarity of 225 grams of Cu(NO2)2 in a total volume of 2.59 L?
Kay [80]

Answer:

The molarity is 0.56\frac{moles}{L}

Explanation:

In a mixture, the chemical present in the greatest amount is called a solvent, while the other components are called solutes. Then, the molarity or molar concentration is the number of moles of solute per liter of solution.

In other words, molarity is the number of moles of solute that are dissolved in a given volume.

The Molarity of a solution is determined by:

Molarity (M)=\frac{number of moles of solute}{Volume}

Molarity is expressed in units (\frac{moles}{liter}).

Then you must know the number of moles of Cu(NO₂)₂. For that it is necessary to know the molar mass. Being:

  • Cu: 63.54 g/mol
  • N: 14 g/mol
  • O: 16 g/mol

the molar mass of Cu(NO₂)₂ is:

Cu(NO₂)₂= 63.54 g/mol + 2*(14 g/mol + 2* 16 g/mol)= 155.54 g/mol

Now the following rule of three applies: if 155.54 g are in 1 mole of the compound, 225 g in how many moles are they?

moles=\frac{225 g*1 mole}{155.54 g}

moles= 1.45

So you know:

  • number of moles of solute= 1.45 moles
  • volume=2.59 L

Replacing in the definition of molarity:

Molarity=\frac{1.45 moles}{2.59 L}

Molarity= 0.56\frac{moles}{L}

<u><em>The molarity is 0.56</em></u>\frac{moles}{L}<u><em></em></u>

5 0
3 years ago
Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reactionP4(g) + 10 Cl2(g) → 4PCl5(s) ΔH°r
weqwewe [10]

Answer:

Therefore  \bigtriangledown H^\circ_{rxn}= -1835 KJ

Explanation:

Enthalpy is denoted by H.

Enthalpy: Total heat change in a chemical reaction is called enthalpy.

The change of entalpy of a reaction is denoted by \bigtriangledown H^\circ_{rxn}

Hass's Law:The change in enthalpy of any process can be determined by calculating the sum of change in enthalpy of each of the steps involved in the process.

g= gas

S= solid

P₄(g)+10Cl₂(g)→ 4Cl₅(s)       \bigtriangledown H^\circ_{rxn}=?

PCl₅(s)→ PCl₃(g)+Cl₂(g) .......(1)       \bigtriangledown H^\circ_{rxn}= +157KJ

P₄(g)+6Cl₂(g)→  4PCl₃(g).............(2)     \bigtriangledown H^\circ_{rxn}= -1207 KJ

If we flip a reaction the value of enthalpy will be change positive to negative or nagative to positive but the numerical value will be remain same.

We need rearrange the equation (1) because in the required equation Cl₂ is on the left side. So we flip the first equation.

PCl₃(g)+Cl₂(g)→PCl₅(s)......(3)          \bigtriangledown H^\circ_{rxn}= -157KJ

Multiplying 4 with equation (3)

4 PCl₃(g)+4Cl₂(g)→4PCl₅(s)......(4)          \bigtriangledown H^\circ_{rxn}=4×( -157)KJ= -628 KJ

Adding equation (2) and (4) we get

P₄(g)+6Cl₂(g)+4 PCl₃(g)+4Cl₂(g)→4PCl₃(g)+4PCl₅(s)    \bigtriangledown H^\circ_{rxn}=( -1207-628)KJ

⇒P₄(g)+10Cl₂(g)→4PCl₃(g)-4PCl₃(g)+4PCl₅(s)      \bigtriangledown H^\circ_{rxn}= - 1835KJ

⇒P₄(g)+10Cl₂(g)→ 4Cl₅(s)       \bigtriangledown H^\circ_{rxn}= -1835 KJ

Therefore  \bigtriangledown H^\circ_{rxn}= -1835 KJ

5 0
3 years ago
Other questions:
  • Which of the following energy sources obtains its energy from gravitational potential energy?
    6·1 answer
  • What three characteristics of matter does chemistry deal with
    13·1 answer
  • How to learn stoichiometry
    15·1 answer
  • What is the end result of a nuclear fusion reaction? two new atoms with smaller nuclei form molecule of atoms forms one new atom
    15·2 answers
  • Describe the motion of molecules in an ice cube and in a radiator in winter
    11·1 answer
  • What are steroids that Aid in the development of muscles called
    12·1 answer
  • Here is the balanced chemical equation for the combustion of isopropyl alcohol: 2C3H7OH(l) + 9O2(g) → 6CO2(g) + 8H2O(g) Multiply
    15·2 answers
  • Why are the offsprings of asexually reproducing organisms genetically identical to their offspring
    15·1 answer
  • Photosynthesis is an example of a
    11·1 answer
  • a solid substance a is soluble in water to the extent of 10 mg/ml of water at 25oc and 100 mg/ml of water at 100oc. you have a s
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!