Question

A reactant r is being consumed in a first-order reaction. What fraction of the initial R is consumed in 4.0 half-lives?

A. 0.063
B. 0.13
C.0.75
D.0.87
E.0.94

Answer 1

In a first-order reaction, the fraction of the initial reactant consumed in a given number of half-lives can be calculated using the equation (1/2)^n, where n is the number of half-lives. In this case, with 4 half-lives, the fraction consumed is 1/16 or 0.0625.

Step-by-step explanation:

A reactant R is being consumed in a first-order reaction. The fraction of the initial R consumed in 4.0 half-lives can be calculated using the equation:

Fraction consumed = (1/2)n

Where n is the number of half-lives. In this case, n = 4. Substituting the values into the equation, we get:

Fraction consumed = (1/2)4 = 1/16 = 0.0625

Therefore, the correct answer is A. 0.063.