I believe the change of state shown in the model is deposition.
Deposition is a process in which gases change phase and turns directly in solids without passing through the liquid phase. It is the opposite of sublimation.
One of the major difference between gases and solids is the distance between molecules; in gases the inter molecular spaces are large, while in solid they are very small, making solids be the most dense, with closely packed molecules. This is evident in the diagram, the phase changed from gases to solids.
Hello!
For the antacid analysis, the chemical reactions that occur in the titration are the following ones:
First, the antacid (composed of weak bases and carbonates) is completely neutralized by the H⁺ ions in the HCl
2HCl + CaCO₃ → CO₂ + H₂O + 2CaCl₂
HCl + OH⁻ → H₂O + Cl⁻
The titration reaction consists in titrating the excess H⁺ ions that are left in the solution, by the following reaction:
H⁺ + NaOH → H₂O + Na⁺
So, when the equivalence point is reached, the solution will go from acid to basic. As bromophenol blue is yellow in acidic solution and blue in basic solution, you'll expect the indicator to change from yellow to blue.
Have a nice day!
C. 18.0g. all you really have to do is add both of them together and you get your answer.