The equation of a curve is \(y = \frac{4}{2x-1}\).

(i) Find, showing all necessary working, the volume obtained when the region bounded by the curve, the \(x\)-axis and the lines \(x = 1\) and \(x = 2\) is rotated through 360° about the \(x\)-axis.

(ii) Given that the line \(2y = x + c\) is a normal to the curve, find the possible values of the constant \(c\).