Question: how many glucose molecules in a gram of sugar?
Answer: Table sugar is composed of sucrose, which is a disaccharide of glucose and fructose, with a molar mass of 342.3 g/mol. This means a sugar cube contains (4.2 / 342.3 =) 0.0123 mol of sucrose, or (0.0123 x 6.022 x 10^23 =) 7.39 x 10^21 molecules of sucrose.