Answer:
The full amount (5.00 g) will be dissolved in 1 L of water at 25°C.
Explanation:
The molecular weight (MW) of Vanillin (C₈H₈O₃) is calculated from the chemical formula as follows:
MW(C₈H₈O₃) = (12 g/mol x 8) + (1 g/mol x 8) + (16 g/mol x 3) = 152 g/mol
If 0.070 mol of C₈H₈O₃ are soluble per liter of water at 25°C, the maximum mass that can be dissolved in 1 L is:
0.070 mol x 152 g/mol = 10.64 g
Since 5.00 g is lesser than the maximum amount that can be dissolved (10.64 g), the added amount will be completely dissolved in 1 L of water at 25°C.
Answer:

Explanation:
X + Y ⟶ XY
mass: 22.7 g x 86.9 g
According to the Law of Conservation of Mass, the mass of the product must equal the mass of the reactants.

If the container is closed, all vapor generated by boiling will stay in the container. If it is at constant volume, the pressure will rise in it. ... Heat pipes boil a liquid at one end and condense it at the other. So the system can remain closed because the contents don't increase: you put in heat, you take out heat.