I need to calculate the pressure exerted by the hydrogen in an eudiometer for a weighing by redox lab.
mass of Mg: .021 g
temp: 295K
barometric pressure: 29.87 inches Hg
volume of H2 gas:
the difference between tiop water level in eudiometer = 322 mm
the difference in the top water level = 165 mm
How do I start this?
I am not certain the height of the water column.
Whatever the height, you change to mm of mercury (inchesHg= heightwater/densitymercury) . Now subtract that from barometric pressure, and you have the pressure of the water vapor.
To calculate the pressure exerted by the hydrogen gas in the eudiometer, you need to use the ideal gas law equation, which states:
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) or 8.314 J/(mol·K))
T is the temperature in Kelvin
In this case, we need to find the volume of the hydrogen gas, so we rearrange the equation as follows:
V = (nRT) / P
To calculate the number of moles, we can use the given mass of magnesium (Mg) and its molar mass.
1. Determine the number of moles of Mg:
- Calculate the molar mass of Mg by looking up its atomic mass (24.31 g/mol)
- Divide the given mass of Mg (0.021 g) by its molar mass to get the number of moles.
2. Convert the barometric pressure to atm:
- Divide the given barometric pressure (29.87 inches Hg) by the conversion factor of 29.92 inches Hg per 1 atm.
3. Convert the difference in the top water level to liters:
- Subtract the lower water level (165 mm) from the upper water level (322 mm) to get the actual difference in height.
- Convert the difference in height to liters by multiplying by the conversion factor of 1 L per 1000 cm^3.
4. Plug the values into the equation:
- Substitute the calculated number of moles, the converted barometric pressure, the temperature in Kelvin (295K), and the calculated volume into the equation V = (nRT) / P.
Once you have plugged in these values, perform the necessary calculations to find the pressure exerted by the hydrogen gas in the eudiometer.