How can the existence of spectra help to prove that energy levels in atoms exist?

Consider 2.4 moles of a gas contained in a 4.0 L bulb at a constant temperature of 32°C. This bulb is connected to an evacuated

Luden [163]

Complete Question

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Answer

a

As the valve is opened , the gas will flow into the empty container until the both containers have the same pressure

b

$\Delta H = 0\ , \Delta E = 0 , q= 0 , w= 0$

c

The driving force for this process is the increase in entropy this is because the movement of the internal energy of the gas into a larger volume, what this does is that it increases the amount of disorder(entropy).

Explanation

In order to obtain the parameter in the part B of the question we are first obtain the initial pressure, using the ideal gas equation

$P = \frac{nRT}{V}$

$P = \frac{(2.4mol)(0.0821\frac{1 atm}{K \cdot \ mol} )}{4.0L}$

$P =15 \ atm$

The next thing is to obtain the new pressure of the gas , using boyle's law

$P_1V_1 = P_2V_2$

$P_2 = \frac{P_1 V_1}{V_2}$

$P_2 = \frac{(15 \ atm)(4.0L)}{24.0 L}$

$P_2 = 2.5 \ atm$

Since the this process is isothermal , the change in heat is equal to zero

i.e q = 0 J

The workdone to move the gas to the other container is zero because the the pressure at this second container is zero due to the fact that it is a vacuum

i.e $w = -P_{external} \Delta V$

$=-(0 \ atm) (24.0 - 4.0L)$

$= 0L \cdot atm$

Since the change in heat is zero and the workdone is zero then the change in internal energy is equal to 0

This is because the change in internal energy is equal to a summation of change in heat and the workdone

i.e $\Delta E = q + w$

$= 0J$

Generally the change in enthalpy is mathematically represented as

$\Delta H = n C_p \Delta T$

Since the temperature is zero this means that the change in temperature is zero , substituting this value for change in temperature into the equation for change in enthalpy

$\Delta H = n C_p (0)$

$= 0J$

7 0

2 years ago

El cuerpo humano tiene unos 6 billones de células (6,0x1012) y la población de la Tierra es de unos 8 000 millones de personas.

zloy xaker [14]

Answer:

En toda la población del mundo hay 0.0797 moles de células

Explanation:

1.0 mol of cells = 6.022 * 10∧23 cells

X mol of cells = 6.0 * 10∧12 cells

- X is cleared to find out how many moles of cells are in a human body:

X = 6.0 * 10∧12 cells / 6.022 * 10∧23 cells

X = 9,963 * 10∧-12 moles of cells per person

In the world there are 8 * 10∧9 people, how many moles in total will there be?

8 * 10∧9 people * 9,963 * 10∧-12 moles of cells per person =

0.0797 moles of molecules in the entire population of the earth.

4 0

2 years ago

Which has not been suggested as a reasonably practical way to store large amounts of hydrogen in relatively small spaces for its

Yakvenalex [24]

Answer: A. Liquefy hydrogen under pressure and store it much as we do with liquefied natural gas today.

Explanation:

Current Hydrogen storage methods fall into one of two technologies;

physical storage where compressed hydrogen gas is stored under pressure or as a liquid; and
chemical storage, where the hydrogen is bonded with another material to form a hydride and released through a chemical reaction.

Physical storage solutions are commonly used technologies but are problematic when looking at using hydrogen to fuel vehicles. Compressed hydrogen gas needs to be stored under high pressure and requires large and heavy tanks. Also, liquid hydrogen boils at -253°C (-423°F) so it needs to be stored cryogenically with heavy insulation and actually contains less hydrogen compared with the same volume of gasoline.

Chemical storage methods allow hydrogen to be stored at much lower pressures and offer high storage performance due to the strong binding of hydrogen and the high storage densities. They also occupy relatively smaller spaces than either compressed hydrogen gas or liquified hydrogen. A large number of chemical storage systems are under investigation, which involve hydrolysis reactions, hydrogenation/dehydrogenation reactions, ammonia borane and other boron hydrides, ammonia, and alane etc.

Other practical storage methods being researched that focuses on storing hydrogen as a lightweight, compact energy carrier for mobile applications include;

Metal hydrides e.g. LiH

Nanostructured metal hydrides

Non-metal hydrides

Carbohydrates

Synthesized hydrocarbons

Aluminum

Liquid organic hydrogen carriers (LOHC)

Encapsulation , e.t.c.

5 0

2 years ago

Which is the most likely way an automotive engineer would use chemistry

kotykmax [81]

The answer is D oooooo

7 0

2 years ago

A blue circle labeled proton and A overlaps a pink circle labeled electron and C. The overlap is labeled B. The Venn diagram com

Sedaia [141]

Answer: The answer would be, "Has mass of 1 amu".

Explanation:

8 0

2 years ago

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