Answer:
I think it's C or D Sorry if I'm Wrong
Explanation:
it just makes the most sense to me
Answer:

Explanation:
Given that,
The dimension of a square chunk of plastic is 5 cm × 5 cm × 5 cm
Mass, m = 200 g
We need to find its density
Density = mass/volume
It will form a cube. It volume = side³
So,

Hence density is 
The half-life of the reaction is 101.9 min
<h3>First order reaction </h3>
When a reaction's pace and reactant concentration are inversely correlated, the process is known as a first-order reaction. To put it another way, the reaction rate doubles when the concentration does. One or two reactants can be present in a first-order reaction, as in the case of the decomposition process.
<h3>The half-life of first-order reaction:-</h3>
The amount of time it takes for the initial concentration of the reactant(s) to decrease by half is known as the half-life of a chemical reaction (abbreviated as "t1/2").
<h3 /><h3>Calculation:-</h3>
a→b
25% reacted means 75% remains
t=42 min
Rate constant
k=(2.303/t)(log a/a-x)
k=(2.303/42)(log 100/100-25 )
k=(0.054) (log 100/75)
k=(0.054)(0.1249)
k=0.0068 per min
half life
t1/2=(0.693/k)
=(0.693/0.0068)
=101.9 min
Learn more about first order reaction here :-
brainly.com/question/27754430
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