Chapter 13.1, Problem 2RQ

Interpretation Introduction

Interpretation:

The SI unit of pressure and the normal unit used for pressure needs to be explained.

Concept Introduction:

As the pressure measuring instruments contain mercury, the pressure can be measured from the rise of the mercury level inside the tube or the height of mercury tube.

Answer to Problem 2RQ

The SI unit for pressure is the pascal (Pa). The units such as atm, torr and mm Hg (millimetres of mercury) are mostly used by chemists. The unit pascal is a small value and using pascal as an atmospheric unit, the large number can be obtained. So, to keep the numbers small, units such as atm, torr and mm Hg are used.

Explanation of Solution

The SI unit for pressure is the pascal (Pa).

1 standard atmosphere = 101,325 Pa

The mostly used units in chemistry for pressure are based on the height of the mercury column (in millimetres). The units such as atm, torr and mm Hg (millimetres of mercury) are mostly used by chemists.

1 standard atmosphere = 1.00 atm = 760.0 mm Hg = 760.0 torr

The unit pascal is a small value and using pascal as an atmospheric unit, the large number can be obtained. So, to keep the numbers small, units such as atm, torr and mm Hg are used.