Question

Question 1.13 Pressure is determined as force per unit area of the surface. The SI unit of pressure, Pascal is as shown below:

1Pa = 1N m–2

If mass of air at sea level is 1034 g cm–2, calculate the pressure in Pascal.

Class XI Some Basic Concepts of Chemistry Page 23

Answer 1

concept : SI unit of mass is kilogram , length is metre and time is second.

$pressure = \frac{force}{area}$

$Pressure = \frac{mg}{A}\\\\=\frac{1034g\times\:9.8ms^{-2}}{cm^2}$

[here mass of air 8n sea level is 1034 g/cm² . it means in 1cm² area mass of air is 1034g .]
= 1034 × 10⁻³ kg × 9.8 m/s²/1×10⁻⁴ m²
= 101332.0 kgm/s² /m²
= 101332.0 N/m²
= 1.01332 × 10⁵ N/m²
= 1.01332 × 10⁵ Pa