Doubts in Chemistry 2009

[niassu]

In OCT/NOV:
Q5c(ii) why can not we write germanium dioxide because in mark scheme I found it germanium oxide
IN MAY/JUNE:
Q5b plz can any one explain how could we know the formula of metal T phosphate because I raelly do not get it.
Thanks in advance

 

[XPFMember]

for the formula of T ,use the volumes to find the ratio ,and for eg if ur ratio is18:6 = 3:1 so formula will be T3PO4