Question

A 100% pure sample of a divalent metal carbonate weighing 2g on complete thermal decomposition releases `44 g c c` of carbon dioxide at STP. The equivalent mass of the metal is
A. `40`
B. `20`
C. `28`
D. `12`

Answer 1

Correct Answer - B
`underset(1mol)(MCO_(3))overset(Delta" ")(to)MO+underset("22400 ml at STP")underset(1mol)(CO_(2))`
448 of `CO_(2)` is given by the metal carbonate = 2g
22400 of `CO_(2)` is given by the metal carbonate
`(2)/(448)xx22400g=100g`
`:.` Mol mass of `MCO_(3)=100`
M+60=100 or atomic mass of metal = 100-60=40
Eq. mass of metal = 40/2=20