Atomic number
atomic mass
group|family
periods
and element symbols
Answer:
3 half-lives
Explanation:
The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.
Let's suppose we start with 64 g of the radioactive element.
- After 1 half-life, the mass of the element will be 32 g.
- After 2 half-lives, the mass of the element will be 16 g.
- After 3 half-lives, the mass of the element will be 8 g.
Total vapor pressure can be calculated using partial vapor pressures and mole fraction as follows:

Here,
is mole fraction of A,
is mole fraction of B,
is partial pressure of A and
is partial pressure of B.
The mole fraction of A and B are related to each other as follows:

In this problem, A is hexane and B is octane, mole fraction of hexane is given 0.580 thus, mole fraction of octane can be calculated as follows:

Partial pressure of hexane and octane is given 183 mmHg and 59.2 mmHg respectively.
Now, vapor pressure can be calculated as follows:

Putting the values,

Therefore, total vapor pressure over the solution of hexane and octane is 131 mmHg.
Answer:
<em>fractional distillation</em><em> </em><em>is</em><em> </em><em>the</em><em> </em><em>most common method for air separation</em><em>.</em>