How many liters of O2 are needed to react completely with 45L of H2S at STP?
2H2S(g) + 3O2(g) --> 2SO2(g) + 2H2O(g)
What's the ratio (from the balanced equation) of O2 to H2S? It looks like
(3 mols O2/2 mols H2S) so that ratio times 45 L? Check my thinking.
To determine the amount of O2 needed to react completely with 45 L of H2S at STP, we can use the stoichiometry of the balanced equation.
From the balanced equation, we can see that 2 moles of H2S react with 3 moles of O2. Therefore, we need to convert the given volume of H2S to moles, and then use the mole ratio to determine the number of moles of O2 required.
1. Convert the given volume of H2S to moles using the ideal gas law:
PV = nRT
Where:
P = pressure at STP = 1 atm
V = volume of gas = 45 L
n = moles of gas (H2S)
R = ideal gas constant = 0.0821 L·atm/mol·K
T = temperature in Kelvin (STP) = 273.15 K
n = PV / RT
n = (1 atm) * (45 L) / (0.0821 L·atm/mol·K * 273.15 K)
2. Calculate the number of moles of O2 needed using the mole ratio from the balanced equation:
2 moles H2S : 3 moles O2
Given moles of H2S * (3 moles O2 / 2 moles H2S)
= (n H2S) * (3 moles O2 / 2 moles H2S)
3. Convert the moles of O2 to liters using the ideal gas law:
n = PV/RT
Where:
P = pressure at STP = 1 atm
V = volume of gas (O2)
n = moles of gas (O2)
R = ideal gas constant = 0.0821 L·atm/mol·K
T = temperature in Kelvin (STP) = 273.15 K
(V O2) = (n O2) * (RT / P)
Plug in the calculated moles of O2 and solve for V O2.
This calculation will give us the number of liters of O2 needed to react completely with 45 L of H2S at STP.
To find out how many liters of O2 are needed to react completely with 45L of H2S at STP (Standard Temperature and Pressure), we can use the given balanced chemical equation:
2H2S(g) + 3O2(g) --> 2SO2(g) + 2H2O(g)
From the balanced chemical equation, we can see that 2 moles of H2S react with 3 moles of O2. So, we need to convert the volume of H2S to moles, then use the stoichiometric ratios to find the moles of O2 required, and finally convert back to liters.
Step 1: Convert the volume of H2S to moles
Since the volume of a gas at STP is directly proportional to the number of moles, we can use the ideal gas law equation to convert the volume of H2S to moles:
n = V / Vm
where:
n = number of moles
V = volume of the gas (in liters)
Vm = molar volume at STP (22.4 L/mol)
Substituting the values:
n(H2S) = 45 L / 22.4 L/mol
Step 2: Use the stoichiometric ratios to find the moles of O2 required
From the balanced chemical equation, we know that 2 moles of H2S react with 3 moles of O2. So, the moles of O2 required can be calculated using the following ratio:
n(O2) = (n(H2S) * 3) / 2
Substituting the value of n(H2S) from Step 1:
n(O2) = (45 L / 22.4 L/mol) * 3 / 2
Step 3: Convert the moles of O2 to liters
Since the volume of a gas at STP is directly proportional to the number of moles, we can use the ideal gas law equation to convert the moles of O2 to liters:
V = n * Vm
Substituting the value of n(O2) from Step 2 and Vm = 22.4 L/mol:
V(O2) = (45 L / 22.4 L/mol) * 3 / 2 * 22.4 L/mol
Now you can calculate V(O2) to find out how many liters of O2 are needed to react completely with 45L of H2S at STP.