Explanation:
I am not understanding your question
Answer: The range of wavelengths of light that can be used to cause given phenomenon is
.
Explanation:
Given: 222 kJ/mol (1 kJ = 1000 J) = 222000 J
Formula used is as follows.

where,
E = energy
h = Planck's constant = 
c = speed of light = 
Substitute the values into above formula as follows.

Thus, we can conclude that the range of wavelengths of light that can be used to cause given phenomenon is
.
Answer:
D
Explanation:
because solar energy is still one of the best technology ever inverted and it is a power saving energy infact most of the things we use this days are solar generated.
I don’t! Know bit I guess it’s C
The reaction is
CaC₂(s) + 2H₂O (l) -----> Ca(OH)₂ (s) + C₂H₂ (g)
As we have data of gas ethyne (or acetylene), C₂H₂
We can calculate the moles of acetylene and from this we can estimate the mass of calcium carbide taken
the moles of acetylene will be calculated using ideal gas equation
PV =nRT
R = gas constant = 0.0821 Latm/molK
T = 385 K
V = volume = 550 L
P = Pressure = 1.25 atm
n = moles = ?
n = PV /RT = 1.25 X 550 / 0.0821 X 385 = 21.75 mol
As per balanced equation these moles of acetylene will be obtained from same moles of calcium carbide
moles of calcium carbide = 21.75mol
molar mass of CaC₂ = 40 + 24 = 64
mass of CaC₂ = moles X molar mass = 21.75 X 64 = 1392g