1.How much energy is emitted by 1 mol of
sodium ions emitting light at this wavelength?
Answer in units of kJ.
This is what I did for this problem, but my answer is wrong
45.8 mg = 0.0458 g
0.0458 g / (23.0 g/mol) = 0.001991 mol Na
0.001991 mol x (6.02214 x 10^23) = 1.199 x 10^21 atoms of Na
1.199 x 10^21 x 3.36 x 10^(-19) =404 J
2.How much energy is emitted by 1 mol of
sodium ions emitting light at this wavelength?
Answer in units of kJ.
3.37 x 10^(-19) J x (6.02214 x 10^23) = 202895 J
= 203 kJ
3.Neils Bohr’s model of the hydrogen atom
explained the unique set of spectral emission
or absorbtion lines seen for hydrogen or other
atoms. Pick the statement that best summarizes
the model.
1. The electrons all formed one single continuous
ring around the nucleus. When light
was shone at the atom, this ring expanded.
Because the electrons were further apart and
higher in energy, light was absorbed as this
happened. The color of light absorbed was
related to the number of electrons in the ring.
2. As the hydrogen atom only had one electron,
it only emitted certain colors of light as
it orbited around the nucleus. Larger atoms
had more electrons so more colors were seen.
3. The electrons occupied discrete circu-
lar orbits; closer orbits were lower in energy.
Emission lines were caused by electrons in
excited atoms jumping from outer orbits to
closer orbits. Each jump corresponded to a
specific amount of energy released.
4. The electrons were trapped inside the
nucleus and specific amounts of energy (specific
colors of light) were needed to release
them. This varied from one element to another.
For this one I think that the answer is number #3, but I'm not sure about the part that says that the electrons jump from the outer orbits to closer orbits
What's the wavelength for #1 and 2?
I notice #1 and #2 are the same question. I remember them being diffferent when I answered this last night.
I assumed a wavelength of 590 nm and with that assumption #2 is worked right and the answer is right. Some of those numbers you used in #1 are not in the problem. I think you copied it wrong.
#3 fits best for the answer to 3.
To answer the first question:
To calculate the energy emitted by 1 mol of sodium ions at a specific wavelength, you need to use the formula:
Energy = Planck's constant * speed of light / wavelength
First, convert the given wavelength to meters so that you can use it in the formula. If the wavelength is given in nanometers (nm), you need to divide it by 10^9 to convert it to meters.
Then, multiply the energy obtained from the formula by Avogadro's number to get the energy emitted by 1 mol of sodium ions.
The calculated energy might be in joules (J). To convert it to kilojoules (kJ), divide the value by 1000.
Now, let's go through your calculations:
1. You correctly converted the given mass of sodium ions to moles.
2. You then multiplied the number of moles by Avogadro's number to find the number of sodium ions.
3. Finally, you multiplied the number of ions by the energy per ion at the given wavelength to get the total energy emitted.
Your result of 404 J seems incorrect. To verify where the error may have occurred, we can go through your steps together:
0.001991 mol x (6.02214 x 10^23) = 1.199 x 10^21 sodium ions
Now, let's calculate the energy:
1.199 x 10^21 x 3.36 x 10^(-19) = – However, this step doesn't seem accurate. It seems you may have used a different value for the energy per ion.
Assuming the value you provided (3.37 x 10^(-19) J) is correct, let's recalculate.
1.199 x 10^21 x 3.37 x 10^(-19) = 4.03813 x 10^2 J
To convert from joules to kilojoules, divide the value by 1000:
4.03813 x 10^2 J / 1000 = 0.403813 kJ
So, the correct answer is approximately 0.404 kJ.
For the second question:
Your calculation is correct. Multiplying the given value (3.37 x 10^(-19) J) by Avogadro's number will give you the energy emitted by 1 mol of sodium ions. To convert the obtained energy from joules to kilojoules, divide by 1000.
3.37 x 10^(-19) J x (6.02214 x 10^23) = 2.02895 x 10^5 J
2.02895 x 10^5 J / 1000 = 202.895 kJ ≈ 203 kJ
So, your answer of approximately 203 kJ is correct.
For the third question:
You are correct that Neils Bohr's model of the hydrogen atom is summarized by statement #3. In this model, the electrons occupy specific discrete circular orbits around the nucleus. These orbits have different energies, with closer orbits having lower energy levels.
In Bohr's model, emission lines are caused by electrons in excited atoms jumping from outer orbits to closer orbits. Each jump corresponds to a specific amount of energy being released as electromagnetic radiation, which manifests as distinct emission lines in the spectrum.