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Jobisdone [24]
3 years ago
10

During a reaction, the enthalpy of formation of an intermediate is 90.3 kJ/mol. During the reaction, 2 moles of the intermediate

are formed as a reactant. What is the enthalpy value for this step of the reaction?
A. -180.6 kJ

B. 90.3 kJ

C. -90.3 kJ

D. 180.6 kJ​
Chemistry
1 answer:
Soloha48 [4]3 years ago
7 0

Answer:

180.6 kJ​

Explanation:

The enthalpy of reaction refers to the energy absorbed or released during a reaction. If heat is absorbed in a reaction, the enthalpy of reaction is positive. If heat is released in a reaction, the enthalpy of reaction his negative.

Since the energy absorbed when one mole of the intermediate is formed is 90.3 kJ/mol, then, when two moles of intermediate is formed, 2 × 90.3 kJ/mol = 180.6 kJ​ of energy is absorbed.

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anzhelika [568]


3.0e23 atoms Ne

"E" means 10^

Then we multiply it by a mole of Ne. By the definetion of a mole, it is always 6.022e23 atoms of an element.

So now, we do this:

3.0e23 atoms Ne x (1 mol Ne / 6.022e23 atoms Ne)

After that, we use molar mass. A mole of Neon is equal, in terms of grams, to its avg. atomic mass. This goes true for any element.

It ends up like this:

3.0e23 atoms Ne x (1 mol Ne / 6.022e23 atoms Ne) x (20.1797 g Ne / 1 mol Ne)

Now cancel out the "atoms Ne" and "1 mol Ne"

You end up with a grand total of...
*plugs everything into a calculator*

10.05298... g Ne.

We need to round to 2 sig. figs. (3.0) so now it's....

10 g Ne.

Note that this method can only be used for converting atoms of an element to mass in grams.
Source(s):
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What would indicate that a physical change takes place when copper is drawn into wire?
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Any change in which the composition of material does not change that is it retains its identity but changes its state or form is known as a physical change.

The properties of metal to draw them into wires is known as ductility.  When a copper is drawn into wire the only change that occurs is change in its shape and size no change will take place into its composition that is the wires are still possessing the properties of copper metal. Thus, a physical change takes place when copper is drawn into wire.

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Answer:

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Explanation:

In geology it is called the gently wavy and rounded relief dome.

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These properties allow, if the pressure is very high, that the salt layers move upwards (due to their lower density). That is, the internal forces produce the elevation of the strata by means of the pressure they exert towards a higher point, generating that the salt looks for its way towards the surface [that is, the salt ascends through the sedimentary layers of the earth's crust, crossing them and deforming them] and causing the bulging structure. The oldest strata are located in the central area of the dome, while the most modern are distributed in the farthest radius. The structure is called salt or diapiro dome, the phenomenon by which it is formed is called diapirism.

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Answer:

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