<u>Answer:</u> The amount remained after 151 seconds are 0.041 moles
<u>Explanation:</u>
All the radioactive reactions follows first order kinetics.
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = 151 sec
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the reactant = 0.085 moles
[A] = amount left after decay process = ?
Putting values in above equation, we get:
![4.82\times 10^{-3}=\frac{2.303}{151}\log\frac{0.085}{[A]}](https://tex.z-dn.net/?f=4.82%5Ctimes%2010%5E%7B-3%7D%3D%5Cfrac%7B2.303%7D%7B151%7D%5Clog%5Cfrac%7B0.085%7D%7B%5BA%5D%7D)
![[A]=0.041moles](https://tex.z-dn.net/?f=%5BA%5D%3D0.041moles)
Hence, the amount remained after 151 seconds are 0.041 moles
<h3>
<u>moles of H2SO4</u></h3>
Avogadro's number (6.022 × 1023) is defined as the number of atoms, molecules, or "units of anything" that are in a mole of that thing. So to find the number of moles in 3.4 x 1023 molecules of H2SO4, divide by 6.022 × 1023 molecules/mole and you get 0.5646 moles but there are only 2 sig figs in the given so we need to round to 2 sig figs. There are 0.56 moles in 3.4 x 1023 molecules of H2SO4
Note the way this works is to make sure the units are going to give us moles. To check, we do division of the units just like we were dividing two fractions:
(molecules of H2SO4) = (molecules of H2SO4)/1 and so we have 3.4 x 1023/6.022 × 1023 [(molecules of H2SO4)/1]/[(molecules of H2SO4)/(moles of H2SO4)]. Now, invert the denominator and multiply:
<h3 />
a specific hypothesis to test with a controlled experiment
