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:

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.

where,

The energy of 1 photon is 6.52 × 10⁻²⁰ J. The energy of 2.67 × 10¹⁹ photons (Energy output = Eo) is:

The percent efficiency of the laser is the ratio of the energy output to the energy input, times 100.

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
ClBr, two nonmetals
Hope this helps you
Ksp of PbBr₂ is 6.60 × 10⁻⁶. The molar solubility of PbBr₂ in pure water is 0.0118M.
Ksp or Solubility Product Constant is an equilibrium constant for the dissociation in an aqueous solution.
Molar solubility (S) is the concentration of the dissolved substance in a solution that is saturated.
Let the molar solubility be S upon dissociation.
PbBr₂ or Lead Bromide dissociates in pure water as follows:
PbBr₂ ----------> Pb⁺² + Br⁻
S 2S
Ksp = [Pb⁺²] [ Br⁻]
Ksp = (S) (2S)²
Ksp = 4S³
6.60 × 10⁻⁶ = 4S³
S = 0.0118M
Hence, the Molar solubility S is 0.0118M.
Learn more about Molar solubility here, brainly.com/question/16243859
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Answer:
<em> 14, 508J/K</em>
ΔHrxn =q/n
where q = heat absorbed and n = moles
Explanation:
<em>m = mass of substance (g) = 0.1184g</em>
1 mole of Mg - 24g
<em>n</em> moles - 0.1184g
<em>n = 0.0049 moles.</em>
Also, q = m × c × ΔT
<em> Heat Capacity, C of MgCl2 = 71.09 J/(mol K)</em>
<em>∴ specific heat c of MgCL2 = 71.09/0.0049 (from the formula c = C/n)</em>
<em>= 14, 508 J/K/kg</em>
ΔT= (final - initial) temp = 38.3 - 27.2
= 11.1 °C.
mass of MgCl2 = 95.211 × 0.1184 = 11.27
⇒ q = 11.27g × 11.1 °C × <em>14, 508 j/K/kg </em>
<em>= 1,7117.7472 J °C-1 g-1</em>
<em />
<em>∴ ΔHrxn = q/n</em>
<em>=1,7117.7472 ÷ 0.1184 </em>
<em>= 14, 508J/K</em>