1st find the pOH = 14 - 4.75 = 9.25
then do 10^-9.25 = 5.62x10^-10 OH- concentration
Answer: Between 1 and 2.
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
............(1)
where,
a = amount of reactant left after n-half lives = 40
= Initial amount of the reactant = 100
n = number of half lives
Putting in the values we get:
![2^n=2.5](https://tex.z-dn.net/?f=2%5En%3D2.5)
taking log on both sides
![nlog(2)=log(2.5)](https://tex.z-dn.net/?f=nlog%282%29%3Dlog%282.5%29)
![n=1.32](https://tex.z-dn.net/?f=n%3D1.32)
Thus half-lives that have elapsed is between 1 and 2
I think the correct answer is D
Answer:
50 kg benzene/hour and 25 kg toluene/hour
Explanation:
According to Lavoisier's law, the mass can't be created either destroyed, thus, the material in the input must be equal to the material in the output + the material formed if there's a reaction + the accumulation in the reactor.
Thus, for bezene:
minput = mtop + mbottom
If 50% of the mass is composed by each substance:
0.5*1000 = 450 + mbottom
500 = 450 + mbottom
mbottom = 50 kg benzene/hour
For toluene:
minput = mtop + mbottom
0.5*1000 = mtop + 475
mtop = 500 -475
mtop = 25 kg toluene/hour
Answer:
Diameter He = 0,1 nm.
Explanation:
Km to nm:
⇒ Diameter He = 1.0 E-13 Km * ( 1000 m / Km ) * ( 1 E9 nm / m )
⇒ Diameter He = 0.1 nm