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
A sample of chlorine containing isotopes of mass numbers 35 and 37 was analysed in a mass-spectrometer. How many peaks correspon
Zolol [24]
Three peaks corresponding to Cl+2 will be recorded. The peaks are for isotope 35, both 35 and 37 and for isotope 37. Mass spectrometer has the ability to detect and separate isotopes, even those differing by a single atomic mass unit. When chlorine isotopes are analysed by mass spectrometer, either peak M or M+2 can be obtained. The intensity ratio in the isotope pattern depends on the natural abundance of the isotopes.
3 0
3 years ago
At a constant pressure and amount of gas, how are temperature and volume related?
RSB [31]
The volume is directly proportional to the absolute temperature so the answer is A.
7 0
3 years ago
What is the molarity of a solution prepared from 85. 0 g cacl2 in 300. 0 g of solution? the density of the solution is 1. 05 g/m
Yuki888 [10]

Answer: 2.6 M

Explanation:

8 0
2 years ago
Define duplet and octet??​
Bogdan [553]
Answer:
duplet-A set of two things or people
Octet-A group of 8 things or people
5 0
3 years ago
How does a magnet separate mixtures like sand and iron filings?​
algol13

Answer:

because iron is magnetic and sand is not

Explanation:

6 0
3 years ago
Read 2 more answers
Other questions:
  • WILL MARK BRAINLIEST<br> How many electrons can be held in the energy level n = 4?
    10·1 answer
  • How do you do Number 4​
    6·1 answer
  • Which condition applies when water boils at 100°c? air pressure equals a specific value (101.3 kpa) air pressure is less than it
    9·2 answers
  • About one hundred thousand years ago, very fluid lava started erupting slowly and gently from a place near a plate boundary. Wha
    10·1 answer
  • Fact check this please
    9·2 answers
  • QUESTION 1
    12·2 answers
  • Can someone do my watershed project ill give brainly and 80 points
    9·1 answer
  • Bromine has a charge of__<br> when it has 36 electrons.
    14·1 answer
  • How many molecules of O2 are present in a 3.90L flask at a temperature of 273K and a pressure of 1.00atm?
    7·2 answers
  • An ideal gas exerts a pressure of 3atm in a 3L container. The container is at a temperature of 298K.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!