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2 years ago

What name is given to the carbon-based structures used in lubricants and nanotubes

Chemistry

2 answers:

sergejj [24]2 years ago

8 0

Answer:

Fullerene, also called buckminsterfullerene, any of a series of hollow carbon molecules that form either a closed cage (“buckyballs”) or a cylinder (carbon “nanotubes”).

Explanation:

A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds to form a closed or partially closed mesh, with fused rings of five to seven atoms. The molecule may be a hollow sphere, ellipsoid, tube, or many other shapes and sizes.

Alborosie2 years ago

8 0

Answer:

khansamueen has already provided an answer. This is an additional note on the many structures carbon may form, called allotropes.

Explanation: Carbon can take on many forms. They are all based only on the carbon atom, and are thus called alloptropes. One of these is diamond, "a" in the attached image.

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According to VSEPR theory, if there are three electron domains in the valence shell of an atom, they will be arranged in a(n) __

wolverine [178]

Answer: B. trigonal planar

Explanation:

Valence Shell Electron Pair Repulsion Theory (VSEPR) is a model to predict the geometry of the atoms making up a molecule where atoms are arranged such that the forces of repulsion are minimum.

If a central atom is bound to three electron domains ,the number of electron pairs is 3, that means the hybridization will be $sp^2$ and the electronic geometry of the molecule will be trigonal planar as the electron pairs will repel each other and attain a position which is most stable.

Example: $BCl_3$ with 3 electron domains has trigonal planar geometry.

6 0

3 years ago

Explain why salivary amylase would not digest protein

CaHeK987 [17]

Answer:This particular enzyme promotes the breakdown of starches into simpler sugars which can be absorbed by the body. Salivary amylase, like most other enzymes, is a protein. ... Consequentlysalivary amylase does not function once it enters the stomach.

Explanation:

6 0

3 years ago

The rate constant of a reaction is measured at different temperatures. A plot of the natural log of the rate constant as a funct

Wittaler [7]

Answer:

The activation energy is 7.11 × 10⁴ J/mol.

Explanation:

Let's consider the Arrhenius equation.

$lnk=lnA-\frac{Ea}{R} .\frac{1}{T}$

where,

k is the rate constant

A is a collision factor

Ea is the activation energy

R is the ideal gas constant

T is the absolute temperature

The plot of ln k vs 1/T is a straight line with lnA as intercept and -Ea/R as slope. Then,

$\frac{-Ea}{R} =-8.55 \times 10^{3} K^{-1} \\Ea= 8.55 \times 10^{3} K^{-1} \times 8.314 \frac{J}{K.mol} =7.11 \times 10^{4} J/mol$

8 0

3 years ago

The bomb calorimeter in Exercise 102 is filled with 987g water. The initial temperature of the calorimeter contents is 23.32. A

Sholpan [36]

Answer:

25.907°C

Explanation:

In Exercise 102, heat capacity of bomb calorimeter is 6.660 kJ/°C

The heat of combustion of benzoic acid is equivalent to the total heat energy released to the bomb calorimeter and water in the calorimeter.

Thus:

$-q_{combust} = q_{water} + q_{calori}$

$q_{combust}$ = heat of combustion of benzoic acid

$q_{water}$ = heat energy released to water

$q_{calori}$ = heat energy released to the calorimeter

Therefore,

$-m_{combust}*H_{combust} = [m_{water}*c_{water} + C_{calori}]*(T_{f} - T_{i})$

1.056*26.42 = [0.987*4.18 + 6.66]( $T_{f}$ - 23.32)

27.8995 = [4.12566+6.660]( $T_{f}$ - 23.32)

( $T_{f}$ - 23.32) = 27.8995/10.7857 = 2.587

$T_{f}$ = 23.32 + 2.587 = 25.907°C

4 0

3 years ago

As the tempreture of a liquid increases the solubility of a liquid of that liquid

anzhelika [568]

As the temperature increases, the solubility of the solute in the liquid also increases. This is due to the fact that the increase in energy allows the liquid to more effectively break up the solute. The additoin of energy also shifts the equilibrium of the reation to the right since it takes energy to dissolve most things and you are adding more of it (this is explained with Le Chatlier principles).

I hope this helps and also I assumed that your question involved the solubility of an ionic substance in a solvent like water. If that was not your question feel free to say so in the comments so that I can answer your actually question.

8 0

3 years ago