WAEC - Chemistry (2001 - No. 38)
If a metal R forms a compound with the formula R(NO3)2 the formula of its tetraoxosulphate (VI) is
R(SO4)2
RSO4
R2SO4
R2(SO4)3
Explication
The compound R formed with R(NO3)2 shows that the metal R has a valency of +2.
If R reacts with tetraoxosulphate(VI), SO4 2- has a valency of - 2.
If both react or combine together, their valencies will cancel out each other, which implies the formula will be RSO4.