Question

At 25°c and 760 mm of Hg pressure a gas occupies 600 ml volume.What will be it's pressure at height where temp is 10°c and volume is 640 ml

Answer 1

Given --->
P₁ = 760 mm
V₁ = 600 ml
T₁ = 25° C = 273 + 25 = 298 K

T₂ = 10° C = 273 + 10 = 283 K
V₂ = 640 ml
P₂ = ?

Using Combined Law of Gas,

P₁V₁/T₁ = P₂V₂/T₂

760 x 600/298 = P₂ x 640 / 283

P₂ = 760 x 600 x 283 / 298 x 640

P₂ = 676.6 mm

So the required pressure is 676.6 mm of Hg

Hope This Helps You!

Answer 2

P1 = 760 mm
V1 = 600 ml 
T1 = 25° C = 273 + 25 = 298 K


P2 = ?
V2 = 640 ml
T2 = 10° C = 273 + 10 = 283 K

Using Combined gas Law equation

combined gas law equation or the ideal gas equation is got by combining all the 3 equations like Charles law , Boyle law and gay-lussac's law

PV = RT

where R is a constant and can be cancelled off

P1V1/T1 = P2V2/T2

760 x 600/298 = P2 x 640 / 283

= 1530.2013 = 2.26 P2

677.08
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