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
Strike441 [17]
3 years ago
7

A lithium flame has a characteristic red color due to emissions of wavelength 671 nm. What is the mass equivalence of 1 mol of p

hotons of this wavelength (1 J = 1 kg·m²/s²)?
Chemistry
1 answer:
e-lub [12.9K]3 years ago
6 0

Answer:

1.98x10⁻¹² kg

Explanation:

The <em>energy of a photon</em> is given by:

  • E= hc/λ

h is Planck's constant, 6.626x10⁻³⁴ J·s

c is the speed of light, 3x10⁸ m/s

and λ is the wavelenght, 671 nm (or 6.71x10⁻⁷m)

  • E = 6.626x10⁻³⁴ J·s * 3x10⁸ m/s ÷ 6.71x10⁻⁷m = 2.96x10⁻¹⁹ J

Now we multiply that value by <em>Avogadro's number</em>, to <u>calculate the energy of 1 mol of such protons</u>:

  • 1 mol =  6.023x10²³ photons
  • 2.96x10⁻¹⁹ J *  6.023x10²³ = 1.78x10⁵ J

Finally we <u>calculate the mass equivalence</u> using the equation:

  • E=m*c²
  • m=E/c²
  • m =  1.78x10⁵ J / (3x10⁸ m/s)² = 1.98x10⁻¹² kg

You might be interested in
A 44% wt/wt solution of H2SO4 has a density of 1.343g/ml. What mass of H2SO4 is 60ml of this solution?
horsena [70]

<u>Answer:</u> The mass of sulfuric acid present in 60 mL of solution is 34.1 grams

<u>Explanation:</u>

We are given:

44 % (m/m) solution of sulfuric acid. This means that 44 grams of sulfuric acid is present in 100 grams of solution.

To calculate volume of a substance, we use the equation:

\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}

Density of solution = 1.343 g/mL

Mass of solution = 100 g

Putting values in above equation, we get:

1.343g/mL=\frac{100g}{\text{Volume of solution}}\\\\\text{Volume of solution}=\frac{100g}{1.343g/mL}=77.46mL

To calculate the mass of sulfuric acid present in 60 mL of solution, we use unitary method:

In 77.46 mL of solution, mass of sulfuric acid present is 44 g

So, in 60 mL of solution, mass of sulfuric acid present will be = \frac{44g}{77.46mL}\times 60mL=34.1g

Hence, the mass of sulfuric acid present in 60 mL of solution is 34.1 grams

3 0
3 years ago
How many moles 1 gram H2SO4
Alexandra [31]

Answer:

0.0102 mole

Explanation:

Use and solve proportions for these with x as the unknown value.

4 0
3 years ago
Which of these are a body fossil A.dinosaur nest B.shrimp burrow C.leaf imprint D.claw print
Darya [45]

The answer is C. leaf imprint


8 0
3 years ago
The electronegativity of C = 2.5, O = 3.5. What type of bond is between C-O? ______ ______ bond
Schach [20]

Answer:

Polar covalent bond

Explanation:

On the basis of electronegativity bond could be ionic bond, polar and non pole covalent bond.

Ionic bond:

It is the bond which is formed by the transfer of electron from one atom to the atom of another element.  

Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity.  The electronegativity difference between bonded atoms is greater than 1.7.

For example:

Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion. Both atoms are bonded together electrostatic attraction occur between anion and cations.

Covalent bond:

It is formed by the sharing of electron pair between bonded atoms.  

The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.  There are two type of covalent bond. Polar and non polar covalent bond. When electronegativity difference is 0.4 - 1.7 bond is polar covalent bond when it is less than 0.4 the bond is non polar covalent.

For example:

In CO the electronegativity of oxygen is 3.5 and carbon is 2.5. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and carbon becomes partial positive. and bond is polar covalent.

5 0
3 years ago
What’s an example of phase change you’ve seen in real life?
givi [52]

Answer:

Melting and boiling will be seen in this example. Condensation might be seen as well. In the Phases of Water Gizmo™, you can heat up or cool down a container of water.

Explanation:

3 0
2 years ago
Other questions:
  • Which element would you expect to be more metallic?<br> (a) Ca or Rb (b) Mg or Ra (c) Br or I
    10·1 answer
  • a 20.4 g aluminum sphere and a 49.4 g iron sphere are both added to 75.2 mL of water contained in a graduated cylinder. what is
    10·2 answers
  • Which term describes the molecule shown below h-c-c-h ethyne c2h2?
    11·2 answers
  • Um pacote de iogurte tem 500g de um produto. A quanto equivale essa massa em quilogramas?
    10·1 answer
  • What is the volume of .04 mol of a gas at .9 kPa and 20 degrees celsius
    11·1 answer
  • Choose all the answers that apply.
    12·2 answers
  • How many formula units in 3.56 g magnesium phosphate
    7·1 answer
  • Reactivity and flammability are are examples of properties.​
    6·1 answer
  • What is the difference between a homogeneous and a heterogeneous mixture?
    10·1 answer
  • Please answer this!!!!!!
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!