Yes, in my opinion 20 ml of soda has a greater mass than 20 ml of water due to higher weight of soda particles as compared to water.
It is because solid substance is more denser than liquid. In 20 ml of soda, there are solid particles in it which make it heavier and denser than liquid water. In order to design this, we have to take two solutions, one having soda whereas the other has water in liquid form with equal concentrations. Then we have o find the density of both solution, that solution which has more density is considered as heavier than other solution. The density of soda is 2.54 g/cm³ whereas the density of water is 1 g/cm³ so it is clear that soda is denser than water.
