Hello, I’m stuck on this chemistry problem for one of my assignments. It’s really confusing me. Does anyone know what the answer is and how I find it?

Can someone me with questions 15 to 17 plz.

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?

Which of the following are good traits of a hypothesis? it will be able to be testedit can predict an outcomeit will explain the observationsall of these