A gas occupies 8 litres at 23'C and 70cmHg what is the volume at stp

3 answers

PV = nRT

For the same amount of gas, n is constant. R is also constant.
So,

PV/T is constant.

=> (PV/T)1 = (PV/T)2

Plug in the given conditions: "8 litres at 23'C and 70cmHg" into the left side, and the STP temp and pressure into the right, to obtain for the latter volume.

Remember to convert Celsius to Kelvin!
T1 = 273 + 23 = 300
T2 = 273 C standard
1 atm = 760 mm Hg = 76 cm Hg standard

n constant
P2 V2 / T2 = P1 V1 / T1
V2 = (P1/P2)(T2/T1) V1
V2 = (70/76)(273/300)8
A thread of mercury of length 15cm is used to trap some air in a capillary tube with uniform cross sectional area and closed at one end.With the tube vertical and the open and uppermost,the length of the trapped air column is rock.calculate the length of the air column when the tube is held(!)horizontally (!!)vertically with the open end underneath.atmospheric pressure =76cm of mercury