The illuminance on a surface is 6 lux and the surface is 4 meters from the light source. What is the intensity of the source?
2 answers:
Answer: D. 96 candelas
Explanation: Illuminance is defined as the quantity of light incident on a surface per unit of area. It depends on the light’s intensity and its distance from the surface.
E= illuminance on the surface (in lux)= 6 lux
I = the intensity of the light from the source (in candelas) = ?
S= distance from the light source to the surface (in meters) = 4 m
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Answer : The mass of ammonia present in the flask in three significant figures are, 5.28 grams.
Solution :
Using ideal gas equation,
where,
n = number of moles of gas
w = mass of ammonia gas = ?
P = pressure of the ammonia gas = 2.55 atm
T = temperature of the ammonia gas =
M = molar mass of ammonia gas = 17 g/mole
R = gas constant = 0.0821 L.atm/mole.K
V = volume of ammonia gas = 3.00 L
Now put all the given values in the above equation, we get the mass of ammonia gas.
Therefore, the mass of ammonia present in the flask in three significant figures are, 5.28 grams.