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Nuetrik [128]
3 years ago
14

The freezing point of 42.19 g of a pure solvent is measured to be 43.17 ºC. When 2.03 g of an unknown solute (assume the van 't

Hoff factor = 1.0000) is added to the solvent the freezing point is measured to be 40.32 ºC. Answer the following questions ( the freezing point depression constant of the pure solvent is 7.67 ºC·kg solvent/mol solute).What is the molality of the solution? m
How many moles of solute are present? mol
What is the molecular weight of the solute? g/molIf the freezing point depression constant of the pure solvent is 7.66 ºC·kg solvent/mol solute calculate the molar mass of the solute. g/mol
Chemistry
1 answer:
vovikov84 [41]3 years ago
4 0

Answer:

The molality of the solution is 0.3716 mol/kg

The number of moles of solute is 0.0157 mol

The molecular weight of the solute is 129.30 g/mol

The molar mass of the solute is 129.32 g/mol

Explanation:

m (molality of the solution) = ∆T/Kf = (43.17 - 40.32)/7.67 = 0.3716 mol/kg

Number of moles of solute = molality × mass of solvent in kilogram = 0.3716 × 0.04219 = 0.0157 mol

Molecular weight of solute = mass/number of moles = 2.03/0.0157 = 129.3 g/mol

When Kf = 7.66 °C.kg/mol

Molar mass = 2.03 ÷ (2.85/7.66 × 0.04219) = 129.32 g/mol

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Which property can be used to tell gold and pyrite apart?
zubka84 [21]

Answer:

D. Malleability

Explanation:

Gold is made up of the element Au and it is a metal.

Pyrite is iron sulfide and it is a non-metal.

  • They have very similar appearance to such an extent that pyrite is widely called the fool's gold.
  • To distinguish between the two, we simply explore their metallic properties.
  • Gold is malleable. Pyrite is not. It will crumble under pressure.
6 0
3 years ago
I need help with Chemistry: Mole Conversion<br> It must be answered in complete detail
Anni [7]

Answer:

As Per Given Information

Number of moles SO₂ ( Sulphur dioxide ) is 0.30

We 've been asked to find the number of atoms in given moles of Sulphur dioxide .

Value of Avogadro Number is 6.022 × 10²³ mol⁻¹

For finding the number of atoms we will use formale

\underline{\boxed{\textbf{\textsf{ Number \: of \: atoms \:  = Given \: moles \:  . Avogadro \: number}}}}

Putting the given value we obtain

\sf \twoheadrightarrow \: Number \: of \: atoms \:  = 0.30 \times 6.022 \times  {10}^{  23}    \\  \\ \sf \twoheadrightarrow \: Number \: of \: atoms \:  = \: 1.8066 \times  {10}^{ 23} atoms

So, the number of atoms in sulphur dioxide is 1.8066 × 10²³

8 0
2 years ago
Which statements describe functions of the backbone? Check all that apply.
Ronch [10]

Answer:

A and E

Explanation:

Backbone is the part of skeletal system and is made of 26  vertebrae in total. The backbone and bones of lower limbs together serve to support the body's weight. Backbone surrounds and protects the spinal cord. Since the vertebrae of backbone are joints together by synovial joints, it allows the flexibility and movement of organisms.

4 0
3 years ago
Read 2 more answers
explain the relationship between the rate of effusion of a gas and its molar mass. methane gas (ch4) effuses 3.4 times faster th
Musya8 [376]

The molar mass of the unknown gas is 184.96 g/mol

<h3>Graham's law of diffusion </h3>

This states that the rate of diffusion of a gas is inversely proportional to the square root of the molar mass i.e

R ∝ 1/ √M

R₁/R₂ = √(M₂/M₁)

<h3>How to determine the molar mass of the unknown gas </h3>

The following data were obtained from the question:

  • Rate of unknown gas (R₁) = R
  • Rate of CH₄ (R₂) = 3.4R
  • Molar mass of CH₄ (M₂) = 16 g/mol
  • Molar mass of unknown gas (M₁) =?

The molar mass of the unknown gas can be obtained as follow:

R₁/R₂ = √(M₂/M₁)

R / 3.4R = √(16 / M₁)

1 / 3.4 = √(16 / M₁)

Square both side

(1 / 3.4)² = 16 / M₁

Cross multiply

(1 / 3.4)² × M₁ = 16

Divide both side by (1 / 3.4)²

M₁ = 16 / (1 / 3.4)²

M₁ = 184.96 g/mol

Learn more about Graham's law of diffusion:

brainly.com/question/14004529

#SPJ1

3 0
2 years ago
Different kinds of wood have different densities. The density of american white oak wood is generally 0.77 g/cm3. If Jim grabs a
mixas84 [53]

Answer:

m= 29.645 g

Explanation:

Density:

Density is equal to the mass of substance divided by its volume.

Units:

SI unit of density is Kg/m3.

Other units are given below,

g/cm3, g/mL , kg/L

Formula:

D=m/v

D= density

m=mass

V=volume

Symbol:

The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.

Given data:

density of wood = 0.77 g/cm³

volume= 38.5 cm³

mass= ?

Solution:

d= m/v

m= d × v

m= 0.77 g/cm³× 38.5 cm³

m= 29.645 g

7 0
3 years ago
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