do not use excel program

1. Nitrogen was employed to determine the surface area of 1.0g sample of silica gel and results obtained shown in table below. The sample of silica gel was maintained at the normal boiling point of liquid nitrogen (77K ). One molecule of nitrogen occupies 16.2 1020m2 area of plane surface. Calculate the specific surface area of silica gel by the BET method. The saturated vapor pressure p0 of nitrogen at 77K is 101.3kPa