Answer: They are arranged by atomic number.
In this reaction 50% of the compound decompose in 10.5 min thus, it is half life of the reaction and denoted by symbol
.
(a) For first order reaction, rate constant and half life time are related to each other as follows:

Thus, rate constant of the reaction is
.
(b) Rate equation for first order reaction is as follows:
![k=\frac{2.303}{t_{1/2}}log\frac{[A_{0}]}{[A_{t}]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt_%7B1%2F2%7D%7Dlog%5Cfrac%7B%5BA_%7B0%7D%5D%7D%7B%5BA_%7Bt%7D%5D%7D)
now, 75% of the compound is decomposed, if initial concentration
is 100 then concentration at time t
will be 100-75=25.
Putting the values,

On rearranging,

Thus, time required for 75% decomposition is 21 min.
Answer:
B) 0.230 M
Explanation:
The first step is to <u>balance the reaction</u> between the Ferrous ion and the permanganate ion:

Then we have to <u>calculate the moles</u> of
:



Then using the <u>molar ratio</u> we can find the moles of
:

Finally we can calculate the molarity:

Also water H2O is made of H+ and OH- ions. so when an acidic substance is added to water the concentration of H+ ions increase.