1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
bogdanovich [222]
3 years ago
7

The bright-red color of highway safety flares comes from strontium ions in salts such as Sr(NO3)2 and SrCO3. Burning a flare pro

duces strontium ions in excited states, which then emit red photons at 606 nm and several wavelengths between 636 and 688 nm. Calculate the energy (in Joules per mole) of the 649 nm emission.
Chemistry
1 answer:
Luden [163]3 years ago
3 0

Answer:

E = 1.8 x 10⁵ J/mol

Explanation:

We are being asked the enery per mol for an emission line corresponding to 649 nm.

The energy of a photon is given by the porduct of Planck's contant times the frequency of the radiation,

                       E = hν

We also know that  the frequency is given by

ν = c/λ

where c is the speed of light (3 x 10 ^8 m/s) and λ is 649 nm given in the problem. Therefore the energy per photon will be given by

E= hc/λ = 6.626 x 10⁻³⁴Js x 3 x 10 ^8 m/s/ 649 x 10 ⁻⁹ m

E = 3.1  x 10 ⁻¹⁹ J/ photon

(Note the wavelength has to be in nanometers  (1nm= 10⁻⁹ m) and that the energy we get is the energy per a single photon. Thus we will need to multiply this result by Avogadro's number to answer this question.

E = 3.1  x 10 ⁻¹⁹ J/ photon x 6.022 x 10 ²³photon/mol

E = 1.8 x 10⁵ J/mol

You might be interested in
Linda has two glasses of apple juice. Glass A has 40 grams of juice at 25 °C. Glass B has 40 grams of juice at 40 °C. Which of t
IgorLugansk [536]
<h2>Answer:</h2>

In both glasses have juices of same mass. But the temperature is different due to which the kinetic energy of molecules in both glasses is different.

As kinetic energy is directly proportional to temperature.

To make the kinetic energy of the molecules equal she should:

  • Heat one glass of 25°C to 40°C.

               or

  • Cool the juice of 40°C to 25°C

4 0
3 years ago
Read 2 more answers
If pea plants with the genotypes RR and rr cross, what genotype will their offspring all have?
Aliun [14]
I think it’ll be Rr
6 0
3 years ago
Read 2 more answers
A man walked 1560 meters in 16000 seconds what is the speed at which he walked
Maslowich
In what meters? miles an hour? i can’t answer unless i know that
5 0
2 years ago
Which of the following is a characteristic of the sun's radiation?
astra-53 [7]

Answer:

it is made up of rays of varying frequencies

3 0
3 years ago
Read 2 more answers
In an electrolytic cell, the magnitude of the standard cell potential is the:______
melamori03 [73]

Answer:

a. minimum voltage that must be supplied for a redox reaction to occur

c. always equal to Eanode - Ecathode

Explanation:

In an electrolytic cell;  The electromotive force(the maximum standard potential difference) of the cell formed by the system is defined as the standard electrode potential of the right handed electrode minus the standard electrode potential of the left hand electrode. (i.e \mathbf{E^{\theta}_{cell}=E_{anode} - E_{cathode}} )

As we all known that the process by which chemical energy is being converted to electrical energy is called the Electrochemical cell. It consists of two half cells , an oxidation half cell reaction and a reduction half-cell reaction.The overall redox reaction results in a flow of electrons in an electric current which is produced by a minimum voltage.

Therefore, option a and c are both correct.

6 0
3 years ago
Other questions:
  • Identify the principal role of photosynthesis. to convert kinetic energy into the chemical energy of sugars to convert solar ene
    14·1 answer
  • Magnesium oxide decomposes into magnesium and oxygen. if 12.09 g of magnesium oxide decomposes to form 7.29 g of magnesium, what
    14·1 answer
  • Which of the following laboratory procedures best illustrates the law of conservation of mass?
    15·2 answers
  • Which description is not a property of an acid? A turns litmus paper red B bitter taste C corrosive D dissolve metals
    12·1 answer
  • Create a Element #Brainliest Challenge
    9·1 answer
  • Describe a covalent bond?
    15·1 answer
  • The staff members working in Radiology department in hospitals, wear shoes with special soles. Justify
    9·1 answer
  • Using the balanced chemical equation below. 2Al2O3 --&gt; 4Al + 3O2 How many moles of oxygen are produced if 11.0 mol of Al are
    6·1 answer
  • The Lanthanides are often be found below the Periodic Table so it will fit nicely on a textbook page. If they were inserted into
    15·1 answer
  • Name
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!