Question

The solfege syllable for the dominant note G is ____. DO TI FA SOL

Answer 1

Sol. Assuming you are in C Major, or in "fixed do"... that means:
C (1)=Do
D (2)=Re
E (3)=Mi
F (4)=Fa
G (5)=Sol
A (6)=La
B (7)=Si or Ti

Answer 2

Also, forgot to mention. If you are using "moveable" solfege, which means your 1st scale degree or "do" moves according to what key you are in, that means that "dominant" you speak of will always be "sol", because it is the 5th degree of the scale. Sol = 5th scale degree = dominant. This is NOT true for fixed do, in which C is always Do. In that case, G is always Sol.