Question

3g of a metal oxide is completely converted into a chloride and it yielded 5g of chloride. what is the equivalent weight of the metal?
a)3.325 b) 33.25 c)12 d)20

Answer 1

Answer

oxidation state of oxygen is -2

lets take metal O.S as +1 or +2 in two cases with its atomic wt. as X

case 1:

for +1 state, its: M20 + 2Hcl ----> 2Mcl + H2O

2x+16 x+35.5

so, it shld be 3/(2x+16) = 2*5/(x+35.5) where x is negative, so its not possible to metal be in +1 state

case 2:

for +1 state, its: M0 + 2Hcl ----> Mcl2 + H2O

x+16 x+72

so, it shld be 3/(x+16) = 5/(x+72)

which gives x = 66.5

so, the metal is Zinc

its eq. wt = 33.25