1. The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K= 0.04 W/m.°K and thickness 0.16m is 10 W/m2. The temperature of the inside wall is - 5°C. The outside wall temperature is
6. If 1.5 moles of oxygen combines with aluminium to form Al2O3, then the weight of aluminium (atomic weight = 27 ) used in this reaction is __________ gm.