For the First-Order Reaction Below,the Initial Concentration of a Is $\mathrm{A} \rightarrow \mathrm{B}$

question 24

Multiple Choice

For the first-order reaction below,the initial concentration of A is 0.80 M.What is the half-life of the reaction if the concentration of A decreases to 0.10 M in 54 seconds? $\mathrm{A} \rightarrow \mathrm{B}$$\quad$$\quad$$\quad$$\quad$$\quad$ rate $=k[\mathrm{~A}]$

• A) 18 s
• B) 24 s
• C) 36 s
• D) 48 s
• E) 51 s

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Definitions:

Helper T Cells

A type of white blood cell that plays a crucial role in the body's immune system by helping to activate other immune cells.

Phagocytosis

The cellular process of engulfing solid particles by a cell to form an internal vesicle known as a phagosome.

Antibodies

Proteins produced by the immune system to identify and neutralize foreign substances like bacteria and viruses.

Antigens

Substances that the immune system recognizes as foreign, triggering an immune response; often parts of pathogens like bacteria, viruses, or fungi.