Question

A gas cylinder can hold 1 Kg of hydrogen at mom temperature and pressure:
i) Find the number of moles of hydrogen present
ii) What weight of $C{O}_2$ can the cylinder hold under similar conditions of temperature and pressure? ($H=1,C=12,O=16$)
iii) If the number of molecules of hydrogen in the cylinder is $X$, calculate the number of $C{O}_2$ molecules in the cylinder under the same conditions of temperature and pressure
iv) State the law that helped you to arrive at the above result.

Answer 1

According to Avogadro's law

at constant temperature, pressure & volume; number of moles of two gases become equal.

$n_1=n_2$ or $n_{H_2}=n_{C{O}_2}$

(i) Number of moles in $1kg$ of $H_2=\frac{1000}{2}g=500$ moles

Thus, $n_{C{O}_2}=n_{H_2}=500$

(ii) Mass of $C{O}_2$ in $500$ moles= $500\times 44=22000$g or $22kg$

(iii) Number of hydrogen molecule in $500$ moles be$X$

$X=500\times M_a$ molecules

$X=500\times 6.022\times {10}^{23}$ molecules

Thus number of $C{O}_2$ molecules in $500$ moles of $C{O}_2$ will be

$X=500\times M_a$ molecules

$X=500\times 6.022\times {10}^{23}$ molecules .

(iv) The law is Avogadro's Law .