A mineral consists of an equimolar mixture of the carbonates of two bivalent metals. One metal is present to the extent of 15.0% by weight, `3.0 g` of the mineral on heating lost `1.10 g` of `CO_(2)`. The percent by weight of other metal is

Options

A. 65
B. 25
C. 75
D. 35

Answer

D

Explanation

`MCO_(3) rarr MO + CO_(2) uarr`
`M'CO_(3) rarr M'O + CO_(2) uarr`
Eq of `CO_(2) = Eq` carbonates of metals
1 mol of `CO_(2) = 1 "mol of" CO_(3)^(2-)`
`1.10 g "of" CO_(2) = (60)/(44) xx 1.10 = 1.5 g "of" CO_(3)^(2-)`
% of `CO_(3)^(2-) = (1.5 xx 100)/(3) = 50%`
% of one metal = 15%
% of another metal `= 100 - 50 - 15 = 35%`