The missing question is:
<em>What is the percent efficiency of the laser in converting electrical power to light?</em>
The percent efficiency of the laser that consumes 130.0 Watt of electrical power and produces a stream of 2.67 × 10¹⁹ 1017 nm photons per second, is 1.34%.
A particular laser consumes 130.0 Watt (P) of electrical power. The energy input (Ei) in 1 second (t) is:
![Ei = P \times t = 130.0 J/s \times 1 s = 130.0 J](https://tex.z-dn.net/?f=Ei%20%3D%20P%20%5Ctimes%20t%20%3D%20130.0%20J%2Fs%20%5Ctimes%201%20s%20%3D%20130.0%20J)
The laser produced photons with a wavelength (λ) of 1017 nm. We can calculate the energy (E) of each photon using the Planck-Einstein's relation.
![E = \frac{h \times c }{\lambda }](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7Bh%20%5Ctimes%20c%20%7D%7B%5Clambda%20%7D)
where,
![E = \frac{h \times c }{\lambda } = \frac{6.63 \times 10^{-34}J.s \times 3.00 \times 10^{8} m/s }{1017 \times 10^{-9} m }= 6.52 \times 10^{-20} J](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7Bh%20%5Ctimes%20c%20%7D%7B%5Clambda%20%7D%20%3D%20%5Cfrac%7B6.63%20%5Ctimes%2010%5E%7B-34%7DJ.s%20%20%5Ctimes%203.00%20%5Ctimes%2010%5E%7B8%7D%20m%2Fs%20%7D%7B1017%20%5Ctimes%2010%5E%7B-9%7D%20m%20%7D%3D%206.52%20%5Ctimes%2010%5E%7B-20%7D%20J)
The energy of 1 photon is 6.52 × 10⁻²⁰ J. The energy of 2.67 × 10¹⁹ photons (Energy output = Eo) is:
![\frac{6.52 \times 10^{-20} J}{photon} \times 2.67 \times 10^{19} photon = 1.74 J](https://tex.z-dn.net/?f=%5Cfrac%7B6.52%20%5Ctimes%2010%5E%7B-20%7D%20J%7D%7Bphoton%7D%20%5Ctimes%202.67%20%5Ctimes%2010%5E%7B19%7D%20photon%20%3D%201.74%20J)
The percent efficiency of the laser is the ratio of the energy output to the energy input, times 100.
![Ef = \frac{Eo}{Ei} \times 100\% = \frac{1.74J}{130.0J} \times 100\% = 1.34\%](https://tex.z-dn.net/?f=Ef%20%3D%20%5Cfrac%7BEo%7D%7BEi%7D%20%5Ctimes%20100%5C%25%20%3D%20%5Cfrac%7B1.74J%7D%7B130.0J%7D%20%5Ctimes%20100%5C%25%20%3D%201.34%5C%25)
The percent efficiency of the laser that consumes 130.0 Watt of electrical power and produces a stream of 2.67 × 10¹⁹ 1017 nm photons per second, is 1.34%.
You can learn more about lasers here: brainly.com/question/4869798
As,
CuCO₃ ⇆ Cu²⁺ + CO₃²⁻
So,
Kc = [Cu²⁺] [CO₃²⁻] / CuCO₃
Or,
Kc (CuCO₃) = [Cu²⁺] [CO₃²⁻]
Or,
Ksp = [Cu²⁺] [CO₃²⁻]
As,
Ksp = 1.4 × 10⁻¹⁰
So,
1.4 × 10⁻¹⁰ = [x] [x]
Or,
x² = 1.4 × 10⁻¹⁰
Or,
x = 1.18 × 10⁻⁵ mol/L
To cahnge ito g/L,
x = 1.18 × 10⁻⁵ mol/L × 123.526 g/mol
x = 1.45 × 10⁻³ g/L
There’s lots of measurements. (m, kg, s, mol, cm, in, mm) etc
Answer:
46.40 g.
Explanation:
- It is a stichiometric problem.
- The balanced equation of the reaction: 4K + O₂ → 2K₂O.
- It is clear that 4.0 moles of K reacts with 1.0 mole of oxygen produces 2.0 moles of K₂O.
- We should convert the mass of K (38.5 g) into moles using the relation:
<em>n = mass / molar mass,</em>
n = (38.5 g) / (39.098 g/mol) = 0.985 mole.
<em>Using cross multiplication:</em>
4.0 moles of K produces → 2.0 moles of K₂O, from the stichiometry.
0.985 mole of K produces → ??? moles of K₂O.
∴ The number of moles of K₂O produced = (0.985 mole) (2.0 mole) / (4.0 mole) = 0.4925 mole ≅ 0.5 mole.
- Now, we can get the mass of K₂O:
∴ mass = n x molar mass = (0.5 mole) (94.2 g/mol) = 46.40 g.