Figure 22 - Boyle’s law: pressure times

Volume is constant

Boyle’s Law. Relation between Pressure and Volume of a Gas. - The relation between the volume of any mass of gas and the pres­sure exerted by the gas upon the walls of the containing vessel was investigated by Robert Boyle and is known as Boyle’s law. This law states that at constant temperature the volume of a given mass of gas is inversely proportional to the pressure to which it is subjected. Thus, if V₁ and P₁ denote the original volume and pres­sure and V₂ and P₂ denote the final volume and pressure,

P₁V₁ = P₂V₂ = constant

or for a constant temperature the product of the pressure and the vol­ume is a constant. By pouring mercury into the open end of the tube (Figure 22), the pressure on the air in AC is increased and its volume decreased. Since the density is inversely proportional to the volume, this law states that at constant temperature the density of a gas is proportional to the pressure.

P₁ d₁

–– = –––

P₂ d₂

For high pressures and low temperatures this law is only an approx­imation. Gases that can be liquefied by the application of pressure do not obey this law near the temperature and pressure at which they begin to liquefy [10, https://en.wikipedia.org/wiki/Gas].

2.9.10 Look through texts 2.9.5 - 2.9.9 and find the English equivalents for the following Russian phrases and word-combinations:

оказывает давление на свой контейнер в два раза сильнее; обращать многие газы в жидкости; сжимать газ до максимально возможного предела; легко сжижаются широко применяемым способом посредством; другими словами; и вот тут-то и заключается вся хитрость; когда нагреваются в тех же самых условиях; полностью соответствует; наи­более важный и хорошо известный; не смотря на факт, что; вплоть до; поднимаются, теряясь из виду; как только это давление устраняется; по мере того, как всё больше воздуха нагнетается в шину.

Play a game with your partner, where one person is the examiner in physics and the other one is examinee, who has to tell him/her all about gasses (use the information from texts 2.9).

Texts Liquids

Read the text, translate it and answer which sentences below are true and which are false.