Answer : The time taken for the reaction is, 28 s.
Explanation :
Expression for rate law for first order kinetics is given by :
where,
k = rate constant = 0.0632
t = time taken for the process = ?
= initial amount or concentration of the reactant = 1.28 M
= amount or concentration left time 't' =
Now put all the given values in above equation, we get:
Therefore, the time taken for the reaction is, 28 s.
Answer: The correct answer is option B.
Explanation: Reactivity of elements is defined as the tendency to loose or gain electrons.
These reactions are a type of single displacement reactions. A single displacement reaction is a type of reaction in which an element displaces another element in a chemical reaction. These are studied with the help of reactivity series.
The element which lies above in the reactivity series can easily displace the element which lies below in the reactivity series.
Option A: This reaction will not yield a stable product because Zinc lies below Aluminium in the reactivity series.
Option B: This reaction will yield a stable product because Sodium lies above Calcium in the reactivity series.
Option C: This reaction will not yield a stable product because Hydrogen lies below Magnesium in the reactivity series.
Option D: This reaction will not yield a stable product because Calcium lies below Barium in the reactivity series.
Option E: This reaction will not yield a stable product because barium lies below Lithium in the reactivity series.
