This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
Increased amount of powder in zinc phosphate cement mixture will cause: 
Select and explain. 
A. Decreased strength, B. Decreased film thickness, C. Decreased solubility, D. Increased setting time
C: Decreased solubility
Answer: C: Decreased solubility 
Explanation: Factors affecting solubility:

Powder-liquid ratio: Thicker mixes show less solubility.
Water content of liquid: Any change in the water content is accompanied by increased solubility.
Effect of moisture contamination: Premature contact of the incompletely set cement with water results in the dissolution and leaching of the surface. Varnish application over the exposed cement margin is beneficial.

Ref: Manappalil P: 91,92