A gas 'x' is collected over water at 17 degree celcius and 750 mm pressure.If the volume of the gas collected is 50 cc then calculate the volume of the dry gas at standard temperature pressure and at 17 degree celcius the vapour of pressure is 14 mm
p1 = total pressure - vapour pressure
= 750-14 mm pressure
= 736 mm pressure
v1 = 50cc
t1 = 290K
p2 = 760 mm pressure
t2 = 273K
v2 = ??
Using P1*V1/T1 = P2*V2/T2, we get
V2 = 45.58cc (approx)
Hope that helps!
45.58 cc
p1=total press.- p2=760mm
vapor press. v2=?
=(750-14)mm t2=273k
=736mm
v1=50cc
t1=(17+273)k
=290k
USE FORMULA- p1v1/t1=p2v2/t2
ANSWER - 45.58cc
To calculate the volume of the dry gas at standard temperature and pressure (STP), we need to correct the volume of the gas collected over water to account for the presence of water vapor.
The pressure exerted by the water vapor is given by the vapor pressure table at the given temperature. At 17 degrees Celsius, the vapor pressure of water is 14 mm.
Step 1: Convert the given pressure from mm to atm
Given Pressure = 750 mm
To convert mm to atm, divide by the conversion factor of 760 mmHg = 1 atm.
Pressure (in atm) = 750 mm / 760 mmHg (or 1 atm) = 0.987 atm
Step 2: Apply Dalton's Law of Partial Pressures
According to Dalton's Law of Partial Pressures, the total pressure exerted by a mixture of gases is equal to the sum of the individual pressures of each gas component.
Total Pressure = Pressure of Gas + Pressure of Water Vapor
Pressure of Water Vapor = Vapor Pressure at the given temperature
In this case, Pressure of Water Vapor = 14 mm (convert to atm, if necessary)
Step 3: Calculate the Pressure of the Dry Gas
Pressure of the Dry Gas = Total Pressure - Pressure of Water Vapor
Pressure of the Dry Gas = (0.987 atm) - (14 mm / 760 mmHg) (or 14 mm / 1 atm)
Step 4: Calculate the volume of the Dry Gas at STP
According to the Ideal Gas Law, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/(mol·K)), and T is the temperature in Kelvin.
At Standard Temperature and Pressure (STP), the pressure is 1 atm and the temperature is 273 K.
Using the formula: P1V1 / T1 = P2V2 / T2, where P1 = Pressure of the Dry Gas, V1 = Volume of the Dry Gas, T1 = Temperature in Kelvin, P2 = STP Pressure (1 atm), V2 = Volume of Dry Gas at STP, and T2 = STP Temperature (273 K), rearrange the formula to solve for V2.
V2 = (P1V1 × T2) / (P2 × T1)
Plug in the values:
P1 = Pressure of the Dry Gas (calculated in step 3)
V1 = Volume of the Gas Collected (given as 50 cc)
T2 = 273 K (STP Temperature)
P2 = 1 atm (STP Pressure)
T1 = given temperature in Celsius + 273 (convert to Kelvin)
Calculate V2 using the formula, and you'll get the volume of the dry gas at STP.
Note: Make sure to convert all units to the same system (e.g., mm to atm, Celsius to Kelvin) for accurate calculations.
Note the correct spelling of celsius.
Total pressure 750 mm Hg.
750 = Pdry gas + PH2O vapor
750 = Pdry gas + 14
P dry gass = ??
Now convert to STP using (P1V1/T1) = (P2V2/T2)
My quickie estimate is about 45 cc but that is an exact answer.