Question

1000 cm3 of hydrogen gas (hydrogen molecules, H2) contains x number of molecules at room temperature and pressure. Determine the number of atoms in 500 cm3 of radon gas (radon atoms) at the same temperature and pressure

Answer 1

Answer: Number of atoms in $500cm^3$ of radon gas (radon atoms) at the same temperature and pressure is $\frac{x}{2}$

Explanation:

According to avogadro's law, volume of a gas is directly proportional to the number of moles present when temperature and pressure is constant.:

$\frac{V_1}{n_1}=\frac{V_2}{n_2}$

$V_1 = Volume of the hydrogen gas = 1000cm^3$

$n_1$ =  moles of hydrogen gas = $\frac{xmolecules}{6.023\times 10^{23}molecules}$

$V_2= Volume of the radon gas =500cm^3$

$n_1$ =  moles of radon gas = ?

$\frac{1000}{\frac{x}{6.023\times 10^{23}}}=\frac{500}{\frac{y}{6.023\times 10^{23}}}$

$y=\frac{x}{2}$

Thus the number of atoms in $500cm^3$ of radon gas (radon atoms) at the same temperature and pressure is $\frac{x}{2}$