The rate constant, k, for the decomposition reaction : k = 0.0124 / days
<h3>Further explanation</h3>
Given
The half-life of 56 days
Required
The rate constant, k
Solution
For first-order, rate law : ln[A]=−kt+ln[A]o
The half-life : the time required to reduce to half of its initial value.
The half life :
t1/2 = (ln 2) / k
k = (ln 2) / t1/2
k = 0.693 / 56 days
k = 0.0124 / days
Answer:
Pb(NO3)2
Cd(NO3)2
Na2SO4
Explanation:
In the first part, addition of HCl leads to the formation of PbCl2 which is poorly soluble in water. This is the first precipitate that is filtered off.
When the pH is adjusted to 1 and H2S is bubbled in, CdS is formed. This is the second precipitate that is filtered off.
After this precipitate has been filtered off and the pH is adjusted to 8, addition of H2S and (NH4)2HPO4 does not lead to the formation of any other precipitate.
The yellow flame colour indicates the presence of Na^+ which must come from the presence of Na2SO4.
Answer: It would be decomposition :)
The symbol for this element is <span>V
</span>, which is the well-known element vanadium.
