The half-life of any substance is the amount of time taken for half of the original quantity of the substance present to decay. The half-life of a radioactive substance is characteristic to itself, and it may be millions of years long or it may be just a few seconds.
In order to determine the half-life of a substance, we simply use:
t(1/2) = ln(2) / λ
Where λ is the decay constant for that specific isotope.
Answer:

Explanation:
Given
Required
Calculate the number of moles
We'll apply the following formula to solve this question

Where

The above equation is an illustration of the ideal gas law
Substitute values for p, V, R and T in:




<em>Hence, there are 243.605 moles</em>
<span> mass of glucose = 0.055 *165 = 9.075 g
vol of methyl alc = 0.185 * 1.87 = 0.346 L = 346 ml
% NaCl ( m/v ) = mass NaCl * 100/ vol of soln
or Vol of Soln = mass NaCl / % NaCl (m/v)
= 32.1 * 100 / 6 = 535 ml the total vol of soln</span>