how to find the pressure exerted by the hydrogen alone?
and the volume of dry hydrogen at SATP?
i have room temperature=23C
room pressure =101.62kPa
volume of h2 gas & H2O vapour
collected =43.2ml
temperature of water = 23C
length of Mg ribbon = 3.00cm
You can correct the wet hydrogen to dry hydrogen at SATP by using
p1v1/t1 = p2v2/t2
p1 = 101.62 kPa - vapor pressure H2O at 23 C. This gives the pressure of H2 alone. You can find the vapor pressure in tables. My table gives 21.1 mm Hg so you will need to convert that to kPa.
v1 = 43.2
t1 = 23 + 273 = ?K.
p2 & t2 are SATP conditions. Solve for v2.
To find the pressure exerted by the hydrogen alone, you need to use the ideal gas law equation, which states:
PV = nRT
Where:
P = pressure
V = volume
n = number of moles
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature in Kelvin
First, let's convert the room temperature from Celsius to Kelvin:
T = 23°C + 273.15 = 296.15 K
Next, we need to determine the number of moles of hydrogen (n) using the volume of hydrogen and the conditions at SATP (Standard Ambient Temperature and Pressure). SATP conditions are defined as 25°C (298.15 K) and 100 kPa.
We have the volume of hydrogen gas and water vapor collected, which is 43.2 mL. However, we need to consider that this volume includes water vapor. To determine the volume of only the dry hydrogen gas, we need to subtract the volume of the water vapor.
To calculate the volume of water vapor, we need to use the temperature of the water, which is also 23°C (296.15 K).
Now, we need to calculate the partial pressure of water vapor at 23°C using the vapor pressure of water.
To find the volume of dry hydrogen gas at SATP, subtract the volume of water vapor from the collected volume. You can use the equation:
Volume of dry hydrogen gas = Volume of hydrogen and water vapor collected - Volume of water vapor
Having determined the volume of dry hydrogen gas, we can use this value, along with the number of moles of hydrogen and temperature, to calculate the pressure exerted by hydrogen alone:
P_hydrogen = nRT / V_hydrogen
Substitute the values into the formula, where R = 0.0821 L·atm/mol·K.
Remember to convert the volume to liters and the pressure to atmospheres to match the units in the equation.
After performing the calculations, you would have found the pressure exerted by hydrogen alone and the volume of dry hydrogen at SATP.