We know at NTP each gas has 22.4L of volume .
[tex]\boxed{\sf 1mol\:of\:CO_2=22.4L=44g}[/tex]
Hence 1g of CO2 contain
[tex]\\ \sf\longmapsto \dfrac{22.4}{44}[/tex]
[tex]\\ \sf\longmapsto 0.5L[/tex]
Now 44.4g of CO_2 has
[tex]\\ \sf\longmapsto 0.5\times 44.4=22.2L[/tex]
