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The website has the complete lesson note for all the subjects in secondary school but this piece showcases the SS1 Chemistry Lesson Note on Dalton’s Law of Partial Pressure. You can use the website search button to filter out the subject of interest to you.

DALTON’S LAW OF PARTIAL PRESSURE

Dalton’s law of partial pressure states that for a mixture of gases that do not react chemically, the total pressure exerted by the mixture of gases is equal to the sum of the partial pressures of the individual gases.

Mathematically, Dalton’s law of partial pressure for a mixture of n gases can be expressed as:

Ptotal = P1 +P2+P3 +………..+ Pn where Ptotal is the total pressure exerted by the mixture of gases that dot not react, P1, P2, P3……Pn are partial pressure of the individual gases.

Example:

If 20.0dm3 of hydrogen were collected over water at 17oC and 79.7kNm-2 pressure; Calculate the

(a) Pressure of dry hydrogen at this temperature.

(b) Volume of dry hydrogen at s.t.p.

( vapour pressure of water is 1.90 kNm-2 at 17OC)

Solution:

(a) PH2  =  Ptotal – Pwater vapour

=  79.7 – 1.90

=  77.8 kNm-2

(b)   =

=

=  14.5dm3