A. Difference in solubility of CaSo4 ½ H2O + CaSO4+ 2H2O
B. Reaction between CaSO4+ 2H2O and water
C. Nucleation and growth of CaSo4 ½ H2O crystals
D. Reaction between hemihydrate and hihydrate
Related Mcqs:
- Porosity present in a acrylic denture is usually the result of______________?
A. A prolonged curing cycle
B. Lack of sufficient pressure applied to flask
C. Insufficient acrylic resin monomer
D. Prolonged bench cooling after curing - Consumption of raw egg white in the diet may result in the deficiency of______________?
A. Riboflavin
B. Biotin
C. Thiamine
D. Pyridoxine - In plaster of paris the setting time is primarily altered by_________________?
A. Altering P / L Ratio
B. Altering temperature of mixing water
C. Speed and length of hand spatulation
D. Addition of accelerators and retarders - As per DNA No. 25, minimum amount of setting expansion required for type V gypsum products_______________?
A. 0.05
B. 0.10
C. 0.15
D. 0.20 - The setting expansion of gypsum products can be reduced by________________?
A. Increased spatulation
B. Adding potassium sulfate
C. Less water powder ratio
D. Allowing setting under water - The setting of zinc phosphate is accelerated by_____________?
A. Adding a drop of water
B. Increasing mixing time
C. Cooling the slab
D. Adding a drop of oleic acid - The addition of which of the following can accelerate the setting time of zinc oxide cement_____________?
A. Zinc acetate
B. Barium sulphate
C. Zinc sulphate
D. Barium chloride - Vulcanization refers to the setting of__________________?
A. Reversible hydrocolloid
B. Mercaptan impression material
C. Zinc Phosphate cement
D. Zinc oxide-eugenol - The setting time of irreversible hydrocolloids can be decreased by_____________?
A. Raising the temperature of water used for maxing
B. Using excess water for maxing
C. Lowering the temperature of water used for mixing
D. None of the above - Setting expansion is advantageous in__________________?
A. Casts
B. Models
C. Investment
D. Dies
