A sample of oxygen gas is collected by displacing water from an inverted bottle as shown in the diagram below. The volume of O2(g) collected is 400.0ml at 25 degree Celsius. The atmospheric pressure is 680 torr and the vapor pressure of water at 25 degree Celsius is 23.8 torr. What mass of O2(g) is collected? Cand calculate the mass of KCLO3(s) required to produce the amount of O2(g) given above. 2KCLO3(s)-->2KCL(s)+3O2(g)
To find the mass of oxygen gas collected, you need to use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
Step 1: Convert the temperature from Celsius to Kelvin.
Given temperature (Celsius) = 25 degrees Celsius.
Add 273.15 to convert to Kelvin.
Temperature (Kelvin) = 25 + 273.15 = 298.15 K.
Step 2: Calculate the partial pressure of the oxygen gas.
Since the oxygen gas is collected by displacing water, the pressure of the oxygen gas would be the total pressure minus the vapor pressure of water.
Partial pressure of oxygen gas (P) = atmospheric pressure - vapor pressure of water
= 680 torr - 23.8 torr
= 656.2 torr.
Step 3: Convert the volume of oxygen gas to liters.
Given volume = 400.0 ml.
Convert to liters by dividing by 1000.
Volume (liters) = 400.0 ml / 1000 = 0.4 L.
Step 4: Calculate the number of moles of oxygen gas.
Using the ideal gas law equation PV = nRT, rearrange to solve for n:
n = (PV) / (RT)
n = (656.2 torr * 0.4 L) / (0.0821 L·atm/(mol·K) * 298.15 K)
Simplifying the units, 1 atm = 760 torr.
n = (656.2 torr * 0.4 L) / (0.0821 L·atm/(mol·K) * 298.15 K)
n = (656.2 torr * 0.4 L) / (0.0821 L·atm/(mol·K) * 298.15 K)
n = 0.06724 mol.
Step 5: Calculate the molar mass of oxygen gas.
The molar mass of oxygen gas (O2) is 32.00 g/mol.
Step 6: Calculate the mass of oxygen gas collected.
Mass = number of moles * molar mass
Mass = 0.06724 mol * 32.00 g/mol
Mass ≈ 2.157 g.
Therefore, the mass of oxygen gas collected is approximately 2.157 grams.
To calculate the mass of KCLO3(s) required to produce the amount of O2(g) given above, you need to determine the molar ratio between KCLO3 and O2 in the balanced equation.
From the balanced equation: 2KCLO3(s) --> 2KCL(s) + 3O2(g)
The molar ratio between KCLO3 and O2 is 2:3.
Step 1: Calculate the number of moles of O2.
Number of moles of O2 = 0.06724 mol.
Step 2: Use the molar ratio to find the number of moles of KCLO3.
Number of moles of KCLO3 = (2/3) * 0.06724 mol
Number of moles of KCLO3 ≈ 0.04483 mol.
Step 3: Calculate the molar mass of KCLO3.
The molar mass of KCLO3 = potassium (K) + chlorine (Cl) + oxygen (O)
Molar mass of KCLO3 = 39.10 g/mol + 35.45 g/mol + (16.00 g/mol * 3)
Molar mass of KCLO3 ≈ 122.55 g/mol.
Step 4: Calculate the mass of KCLO3 required.
Mass of KCLO3 = number of moles * molar mass
Mass of KCLO3 ≈ 0.04483 mol * 122.55 g/mol
Mass of KCLO3 ≈ 5.499 g.
Therefore, approximately 5.499 grams of KCLO3(s) are required to produce the given amount of O2(g).