Vitamin C has an empirical formula of C3H4O3 and a molecular mass of 176 amu. What is its molecular formula?

Can anyone please help, I have no idea how to do this so step by step would be nice.

What you have to do is make the amu of each element, multiplied by its subscript, equal 176. So, to keep the ratio the same, you have to multiply every subscript by the same number.

The equation is
176= x(36+4+48)
176= 88x
2=x

Two is the magic number we’re looking for…
Multiply each element’s subscript by 2, and the answer is
C6H8O6