I don't really know how to go about this, Please help
1. Calculate the number of moles of the gas. Calculate the volume the gas would occupy at 100.0 C and 15.0 atm.
10.8 g He
2. Given the volume of 54.0 C and 790 torr, calculate the number of moles and mass.
38.1 L CO
1. Use PV = nRT.
P = 15
V = ?
n = grams/molar mass = 10.8/4 = ?
R = 0.08206 L*atm/mol*L
T = 273 + 100 = ?
2 is the same type problem but turned around a little.
Sure! Let's break down both questions step-by-step.
1. Calculate the number of moles of the gas and the volume it would occupy at 100.0°C and 15.0 atm.
To calculate the number of moles of the gas, we need to use the formula:
moles = mass / molar mass
In this case, the mass of the gas is given as 10.8 g He. The molar mass of helium (He) is approximately 4.00 g/mol. Plugging these values into the formula, we get:
moles = 10.8 g / 4.00 g/mol
moles = 2.7 mol
So we have 2.7 moles of helium gas.
To calculate the volume the gas would occupy at 100.0°C and 15.0 atm, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure (15.0 atm)
V = volume (unknown)
n = number of moles (2.7 mol)
R = ideal gas constant (0.0821 L·atm/(mol·K))
T = temperature in Kelvin (100.0°C + 273.15 = 373.15 K)
Rearranging the equation to solve for V, we get:
V = nRT / P
V = (2.7 mol)(0.0821 L·atm/(mol·K))(373.15 K) / 15.0 atm
V ≈ 19.8 L
Therefore, the gas would occupy approximately 19.8 liters at 100.0°C and 15.0 atm.
2. Given the volume of 54.0 L at 790 torr, calculate the number of moles and mass.
To calculate the number of moles of the gas, we can use the ideal gas law equation (PV = nRT) again, rearranged to solve for n:
n = PV / RT
The given values are:
P = 790 torr
V = 54.0 L
R = 0.0821 L·atm/(mol·K)
T = temperature in Kelvin (unknown in this case)
Remember that temperature needs to be in Kelvin, so let's say the temperature is given as 25.0°C. We convert it to Kelvin using the equation T(K) = T(°C) + 273.15:
T = 25.0°C + 273.15 = 298.15 K
Now, let's calculate the number of moles:
n = (790 torr)(54.0 L) / (0.0821 L·atm/(mol·K))(298.15 K)
n ≈ 100 mol
So we have approximately 100 moles of CO gas.
To calculate the mass of CO gas, we use the formula:
mass = moles × molar mass
The molar mass of CO (carbon monoxide) is approximately 28.01 g/mol. Plugging in the values, we get:
mass = 100 mol × 28.01 g/mol
mass ≈ 2801 g
Therefore, the mass of the CO gas is approximately 2801 grams.