power = work/time
watt = joule/sec
a) power = 0.10 watt = 0.1joules/sec
work = power * time
= 0.10 * 1 =0.1joules
work is northing but energy
therefore energy is 0.1joules
according to planks quantum theory E = nhν where nis the no. of photons ; h is planks constant; ν isfrequency
hence, n = E/hν
or n = Eλ/hc (ν = c/λ)
n = (0.1*700*10^-9)/6.625*10^-34*3*10^8 = 0.3522*10^18photons
b) similar to the above calculation
here E = 1.0joules
n = (1.0*700*10^-9)/6.625*10^-34*3*10^8 = 0.3522*10^17photons
Answer:
The percent recovery from re crystallization for both compounds A and B is 69.745 and 81.44 % respectively.
Explanation:
Mass of compound A in a mixture = 119 mg
Mass of compound A after re-crystallization = 83 mg
Percent recovery from re-crystallization :
Percent recovery of compound A:
Mass of compound B in a mixture = 97 mg
Mass of compound B after re-crystallization = 79 mg
Percent recovery of compound B:
The elements in each pair have in common it that they are metaloids
Answer: A plot of the natural log of the concentration of the reactant as a function of time is linear.
Explanation:
Since it was explicitly stated in the question that the half life is independent of the initial concentration of the reactant then the third option must necessarily be false. Also, the plot of the natural logarithm of the concentration of reactant against time for a first order reaction is linear. In a first order reaction, the half life is independent of the initial concentration of the reactant. Hence the answer.
