On the afternoon of March 16, 2005, China Catering Group, a subsidiary of KFC, issued a statement and publicly apologized. KFC roasted wings in New Orleans and roasted chicken in New Orleans.
(1) The relative molecular weight of Sudan Red No.1 is:12×16+12+14× 2+16 = 248;
(2) According to the chemical formula of Sudan Red No.1, the mass ratio of each element is C: H: N: O = (12×16): (1×12): (14× 2).
(3) The mass fraction of nitrogen in Sudan Red No.1 is14× 2248×100% ≈1.3%.
So the answer is: (1) 248; （2）C：H：N：O=48：3：7：4； （3） 1 1.3%．