A. Very high pressure
B. Atmospheric pressure
C. Room temperature
D. > 600°C
Related Mcqs:
- Conversion of yellow phosphorous to red phosphorous is done by heating it in covered retorts at ____________ °C in absence of air?
A. 50-80
B. 250-400
C. 1000-1200
D. 800-900 - Red phosphorous is changed into white phosphorous by______________________?
A. Heating in presence of light
B. Melting under pressure
C. Vaporisation followed by condensation
D. None of these - Electric furnace method for production of phosphorous uses phosphate rock and _________________________?
A. Phosphoric acid
B. Coke
C. Sulphuric acid
D. Silica and coke - A mixture of phosphate rock ______________ is heated in an electric furnace to produce phosphorous?
A. Salt & coke
B. Sand & coke
C. And coke
D. And sand - Yield of elemental phosphorous from rock phosphate is about _____________ percent?
A. 1-2
B. 15-25
C. 40-45
D. 60-65 - Fusion zone in the electric furnace used for reduction of phosphate rock to elemental phosphorous is maintained at ______________ °C?
A. 250-300
B. 500-750
C. 950-1050
D. 1400-1450 - Conversion of yellow phosphorus to red phosphorous is done in retorts at 250-450°C in the ___________________?
A. Presence of an inert atmosphere
B. Presence of a reducing atmosphere
C. Absence of air
D. Presence of an oxidising atmosphere - Both white phosphorous as well as red phosphorous_________________?
A. Are soluble in CS2
B. Burns when heated in air
C. Reacts with hot caustic soda solution to give Phosphine
D. All A., B., and C. - Maximum nitrogen percentage is in________________?
A. Ammonium sulphate
B. Calcium ammonium nitrate
C. Urea
D. Liquid ammonia - Which of the following set of conditions is favourable for the maximum yield of ammonia by Haber’s process ?
A. High pressure, low reactants concentration, high temperature
B. High pressure, low reactants concentration, low temperature
C. High pressure, high reactants concentration, low temperature
D. Low pressure, high reactants concentration, low temperature
