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3 years ago

How do van der waals forces hold molecules together?

Chemistry

1 answer:

IRINA_888 [86]3 years ago

4 0

Answer:

Electrostatic Van de Waals forces act between molecules to form weak bonds. The types of Van der Waals forces, strongest to weakest, are dipole-dipole forces, dipole-induced dipole forces and the London dispersion forces. The hydrogen bond is based on a type of dipole-dipole force that is especially powerful. These forces help determine the physical characteristics of materials.

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You have a hard glass flask that you plug up with a stopper at room temperature (25 C) and an internal pressure of 1 atm. If you

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Answer:

pressure of 0atm

Explanation:

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3 years ago

Why can't all mixtures be classified as solutions?

shusha [124]

D. Not all mixtures are heterogeneous

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3 years ago

A sample of paraffin wax undergoes the following change: C25H52(s) → C25H52(l)

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Answer:

Explanation:

(a) Answer: Intermolecular forces

The reason for this answer is because the substance (paraffin wax) only changed it's state from solid to liquid and didn't undergo a breakage in it's covalent bond within it's carbon chain which would have produced another substance.

(b) Solid substances are generally more dense than there corresponding liquid substances because the more compact particles are (which occurs in solids), the more dense they become. They are thus more dense than liquids because liquids have there particles loosely packed and well spaced making them less dense than there corresponding solids. Hence, the solid paraffin wax was going to become less dense because it's particles moved from being tightly packed (as solids) to being loosely packed (as liquids). Density refers to mass per volume but can also be described as the level of compactness of a substance. Thus, since liquid is not as compact as solid, it can be said to be less dense than solids.

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2 years ago

How Do Glow Sticks Glow?

Gekata [30.6K]

Answer:

All liquid glow products depend on a chemical process known as CHEMILUMINESCENCE to produce their light. Chemiluminesence is a chemical reaction that causes a release of energy in the form of light. To produce this light the electrons in the chemicals become excited and rise to a higher energy level.

To utilise this process glowsticks contain two liquids; hydrogen peroxide and tert-butyl alcohol. When mixed together it is these liquids that create the glow. Fluorescent dyes are also used in the alcohol to alter the colour of the light emitted.

Explanation:

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3 years ago

The reaction (CH3)3CBr + OH- (CH3)3COH + Br- in a certain solvent is first order with respect to (CH3)3CBr and zero order with r

son4ous [18]

Answer and Explanation:

The rate constant (K) is related to activation energy (Ea), frequency factor (A) and temperature (T) in Kelvin by the equation

R = molar gas constant

K = A(e^(-Ea/RT))

Taking natural log of both sides

In K = In A - (Ea/RT)

In K = (-Ea/R)(1/T) + In A

Comparing this to the equation of a straight line; y = mx + c

y = In K, slope, m = (-Ea/R), x = (1/T) and intercept, c = In A

a) From the question, m = (-Ea/R) = -1.10 × (10^4) K

(-Ea/R) = -1.10 × (10^4) = -11000

R = 8.314 J/K.mol

Ea = -11000 × 8.314 = 91454 J/mol = 91.454 KJ/mol

b) c = In A = 33.5

A = e^33.5 = (3.54 × (10^14))/s

c) K = A(e^(-Ea/RT))

A = (3.54 × (10^14))/s, Ea = 91454 J/mol, T = 25°C = 298.15 K, R = 8.314 J/K.mol

K = (3.54 × (10^14))(e^(-91454/(8.314×298.15))) = 0.0336/s

QED!

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3 years ago