50 cm\(_3\) of gas was collected over water at 10ºC and 765 mm Hg. Calculate the volume of the gas at s.t.p. if the saturated vapour pressure of water at 10ºC is 5mm Hg

godstamtam

7 years ago

P1V1/T1 = P2V2/T2
Therefore V2 = P1V1T2/P2T1
P1 = 765-5 = 760
V1 = 50
T1 = 10+273 = 283(changing to kelvin)
P2 = 760(presure at stp)
V2 = ?(unknown)
T2 = 273(temp. at stp)

V2 = 760*50*273/760*283
(760 cancels each other)
V2 = 50*273/283
V2 = 13650/283
V2 = 42.23

Ninny

9 years ago

The true pressure of the hydrogen gas=

(765-5)=760 then

p1v1/t1=p2v2/t2 gas equation

p1=760, v1=50, t1=(10+273)k=283

p2=s.p(760), v2?, t2=s.t(273)



then 760×50×273/760×283=48.23cm³

ogunleyeferanmi5

5 years ago

V1=50
V2=?
P1=765-5
P2 = 760(pressure at stp)
T1=283
T2=273 (temperature at stp)

760x50/283=760xV2/237
So u will nw cross mutiply it
10374000/215080=48.2300
V2= 48.23 ans

dandano

7 years ago

D is the answer using general gas equation

Dr.Aliyu

3 years ago

The first pressure was recorded as 765mmhg in the question which contradict the one used in solving the question which is 780mmhg.
Going by the solution, if the pressure is 780mmhg, then the answer is A 49.5 not D 48.23

Akpodorcas

3 months ago

👎

Myschool Abby

3 years ago

We have made appropriate corrections.
Thanks.

Aikhienomianmomoh1980

3 years ago

the question is not correct

Nepsylee

1 year ago

why are we removing 5 from 765 I'm confused please 😭

Subex123

7 months ago

Why We Subtract 5:
When gas is collected over water, the collected gas is actually a mixture of the dry gas AND water vapor. The total pressure (765 mm Hg) includes both:
• Pressure of the dry gas
• Pressure of water vapor (5 mm Hg)
To find the pressure of just the dry gas, we subtract the water vapor pressure:
P₁ = 765 - 5 = 760 mm Hg (pressure of dry gas only)