Answer:
- <u>2.59 × 10⁻⁷ m = 259 nm</u>
Explanation:
You need to calculate the wavelength of a photon with an energy equal to 463 kJ/mol, which is the energy to break an oxygen-hydrogen atom.
The energy of a photon and its wavelength are related by the Planck - Einstein equation:
Where:
- h = Planck constant (6.626 × 10⁻³⁴ J . s) and
- ν = frequency of the photon.
And:
Where:
- c = speed of light (3.00 × 10⁸ m/s in vacuum)
- λ = wavelength of the photon
Thus, you can derive:
Solve for λ:
Before substituting the values, convert the energy, 463 kJ/ mol, to J/bond
- 463 kJ/ mol × 1,000 J/kJ × 1 mol / 6.022 × 10 ²³ atom × 1 bond / atom
= 7.69×10²³ J / bond
Substitute the values and use the energy of one bond:
- λ = 6.626 × 10⁻³⁴ J . s × 3.00 × 10⁸ m/s / 7.69×10²³ J = 2.59 × 10⁻⁷ m
The wavelength of light is usually shown in nanometers:
- 2.59 × 10⁻⁷ m × 10⁹ nm / m = 259 nm ← answer
Answer:
Cl⁻ is the reducing agent.
Explanation:
The redox reaction is as follow:
MnO₂ + 4H⁺ + 2Cl⁻ → Mn²⁺ + 2H₂O + Cl₂
One should know the following terms,
Reducing agent:
An atom or element which tends to lose electron during a chemical reaction and get itself oxidized. In above reaction Cl⁻ is reducing agent as it carries a negative charge (means it has one extra electron) on the reactant side while, it has zero oxidation state on the product side. It means going from -1 to 0 the Cl lost one electron hence, it is an reducing agent according to definition.
Oxidizing Agent:
On the other hand oxidizing agent is an element or compound which tends to accepts electron(s) and get itself reduced. In above reaction Mn has an oxidation state of +4 on reactant side and after gaining electron from Cl it has changed to +2 on the product side. Hence, it has reduced but has oxidized the Cl atom so it is an oxidizing agent according to definition.
Answer:
87.5 mL
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Answer: The amount left after 4.94 days is
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) to calculate amount left after 4.94 days
The amount left after 4.94 days is