The blue color of copper (ii) sulfate will change to green, yellow, orange ,red and then a dark red or brown.
Glucose is a reducing sugar; reducing sugars are sugar that forms an aldehyde or ketone in the presence of an alkaline solution. Reducing sugars reduce the blue copper sulfate from the Benedict's solution to a red brown copper sulfide; which is seen as the precipitate and is responsible for the color change.
6g of hydrogen gas is my answer. I'm sorry if I'm wrong.
