Question

Equivalent of a metal carbonate is 69 g Find equivalent weight of metal.

Answer 1

let the metal carbonate be:
M2(CO3)X
molar mass = 2M + 60x
moles = 6.9/( 2M + 60x)

Now,
Molarity = Normality/V.F
= 2/1 = 2
MV = moles
moles = (2*60-20*1)/1000 = 100/1000 = 0.1 { 20 mm neutralized by OH-}
6.9/Z = 0.1
Z = 6.9/0.1
Z = 69
Molar mass of metal carbonate is hence, 69.
moles of metal = 0.1*2 = 0.2
Eq. Weight = moles x valence factor.
= 0.2 x 2
= 0.4

Answer 2

Answer:

39

Explanation:

Equivalent mass of a metal is x

Equivalent mass of the metal carbonate= eq.mass of metal + eq.mass of carbonate

                                              69 = x + 60/2

                                               x = 39

equivalent CO3 = 12+16x3= 60/2=30

The reason we divide it in 2 is the charge of the carbonate anion -2