ideal gas law. but you are talking about moles of gas not miles
According to Avogadro's Law, same volume of any gas at standard temperature and pressure will occupy same volume. And one mole of any Ideal gas occupies 22.4 dm³ (1 dm³ = 1 L).
Data Given:
n = moles = ?
V = Volume = 16.8 L
Solution:
As 22.4 L volume is occupied by one mole of gas then the 16.8 L of this gas will contain....
= ( 1 mole × 16.8 L) ÷ 22.4 L
= 0.75 moles
Result:
16.8 L of Nitrogen gas will contain 0.75 moles at standard temperature and pressure.
<span>For isotopes of any element, the number of protons remains the same, BUT the number of neutrons changes. Since each of the isotopes listed is phosphorus, All three have 15 protons. (They have 16, 17 and 18 protons respectively.)</span>
The gas laws describe and predict the behavior of gases with an explanation and experimental data
So the given statement is False.
2) The volume of gas can be calculated based on Avagadro's law
It states that the volume of a gas is directly proportional or varies with the moles of the gas. Higher the moles more the volume, condition is the pressure and temperature are constants in the two conditions
Thus as here the pressure and temperature of nitrogen gas is kept constant
V α moles
or

Where
V1 = 6 l
n1 = 0.50 mol
V2 = ?
n2 = 0.75 mol
On putting values
V2 = 6 X 0.75 / 0.5 = 9 L
so resulting volume of the gas will be 9L