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3 years ago

Explain why the following are made of thermosetting plastics.

Chemistry

1 answer:

rusak2 [61]3 years ago

6 0

Answer:

a: they're used in saucepan handles 'cause they don't soften when heated and also 'cause they cant be bent easily.

b: thermosetting plastics are bad electricity conductors. they don't get moulded and are also hard and strong.

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What happens to the individual molecules of a liquid as they gain enough kinetic energy to escape the surface of the liquid?

Bumek [7]

Im pretty sure They freeze

7 0

2 years ago

Read 2 more answers

Some activities that are generally considered to be work are not called work by scientists. Explain why.

Flura [38]

Answer:

Certain things we think of as hard work, such as writing an exam or carrying a heavy load on level ground, are not work as defined by a scientist. The scientific definition of work reveals its relationship to energy—whenever work is done, energy is transferred.

For work, in the scientific sense, to be done, a force must be exerted and there must be motion or displacement in the direction of the force.

5 0

2 years ago

What is the molarity of 60.0 grams of NaOH dissolved in 750 milliliters of water?

Bumek [7]

Answer:

The correct answer option is B) 2.0 M.

Explanation:

We are given the number of grams of NaOH (Sodium Chloride) which are dissolved in 750 milliliters of water and we are to find its molarity.

We know the formula of molarity:

Molarity = (mass * 1000) / (volume * molecular mass)

Volume = 750 ml = 750 cm $^3$

Molecular mass = 40

Mass = 60 grams

Substituting these values in the above formula:

Molarity = $\frac{(60*1000)}{750*40}$ = 2.0 M

8 0

2 years ago

In IR spectroscopy, we normally talk about "frequencies" when in reality we are referring to wavenumbers. What is the mathematic

Svetach [21]

Answer:

Here's what I get.

Explanation:

(b) Wavenumber and wavelength

The wavenumber is the distance over which a cycle repeats, that is, it is the number of waves in a unit distance.

$\bar \nu = \dfrac{1}{\lambda}$

Thus, if λ = 3 µm,

$\bar \nu = \dfrac{1}{3 \times 10^{-6} \text{ m}}= 3.3 \times 10^{5}\text{ m}^{-1} = \textbf{3300 cm}^{-1}$

(a) Wavenumber and frequency

Since

λ = c/f and 1/λ = f/c

the relation between wavenumber and frequency is

$\bar \nu = \mathbf{\dfrac{f}{c}}$

Thus, if f = 90 THz

$\bar \nu = \dfrac{90 \times 10^{12} \text{ s}^{-1}}{3 \times 10^{8} \text{ m$\cdot$ s}^{-1}}= 3 \times 10^{5} \text{ m}^{-1} = \textbf{3000 cm}^{-1}$

(c) Units

(i) Frequency

The units are s⁻¹ or Hz.

(ii) Wavelength

The SI base unit is metres, but infrared wavelengths are usually measured in micrometres (roughly 2.5 µm to 20 µm).

(iii) Wavenumber

The SI base unit is m⁻¹, but infrared wavenumbers are usually measured in cm⁻¹ (roughly 4000 cm⁻¹ to 500 cm⁻¹).

8 0

3 years ago

13. Would you expect oxygen to form a cation or anion? How many electrons would it gain or lose? Why?

netineya [11]

Answer: C)Anion, it would gain 2 electrons to satisfy the octet rule.

Explanation:

Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.

The electrons are filled according to Afbau's rule in order of increasing energies and thus the electronic configuration of oxygen with 8 electrons is

$O:8:1s^22s^22p^4$

The cation is formed by loss of electrons and anions are formed by gain of electrons.

In order to complete its octet and get stable, it gains 2 electrons and thus would form an anion.

$O^{2-}:10:1s^22s^22p^6$

7 0

3 years ago