Assuming all volume measurements are made at the same temperature and pressure, how many liters of oxygen gas would it take to react completely with 7.25 liters of hydrogen gas? Show all of the steps taken to solve this problem.
Unbalanced equation: H2 (g) + O2 (g) yields H2 O(g)
Balance the equation. The long way is to follow these steps which will solve almost any stoichiometry problem.
http://www.jiskha.com/science/chemistry/stoichiometry.html
There is a short cut that may be used when all of the materials are in the gaseous hase. Just use volume, convert frm one material to another by using the coefficients in the balanced equation you have it.
To solve this problem, we first need to balance the equation, then use stoichiometry to find the ratio between the given gases, and finally calculate the amount of oxygen gas needed. Here are the steps to solve the problem:
Step 1: Balance the equation
The given equation is unbalanced, so we need to balance it before proceeding with the calculations:
H2 (g) + O2 (g) → H2O (g)
Step 2: Determine the stoichiometric ratio
The balanced equation tells us that 1 molecule of H2 reacts with 1 molecule of O2 to form 2 molecules of H2O. We need to convert the given volume to the number of molecules using the ideal gas law:
PV = nRT
Since the temperature and pressure are constant, we can rewrite the equation as:
V = n
Using the molar volume at standard temperature and pressure (STP), which is 22.4 L/mol, we can calculate the number of molecules:
Number of molecules = 7.25 L / 22.4 L/mol
Step 3: Calculate the amount of oxygen gas needed
Now that we have the number of molecules, we can determine the stoichiometric ratio between hydrogen and oxygen. From the balanced equation, we see that 1 molecule of H2 reacts with 1 molecule of O2.
Therefore, the number of oxygen molecules needed is the same as the number of hydrogen molecules:
Number of oxygen molecules = Number of hydrogen molecules
Now, we can convert the number of oxygen molecules to liters using the molar volume at STP:
Number of liters of oxygen gas = Number of oxygen molecules * 22.4 L/mol
So, to find the number of liters of oxygen gas needed to react completely with 7.25 liters of hydrogen gas, follow these steps:
1. Balance the equation: H2 (g) + O2 (g) → H2O (g)
2. Determine the stoichiometric ratio and calculate the number of molecules of hydrogen gas from the given volume.
3. Use the stoichiometric ratio to convert the number of hydrogen molecules to the number of oxygen molecules.
4. Convert the number of oxygen molecules to liters using the molar volume at STP.
Note: It's important to use the molar volume at STP (22.4 L/mol) because the problem assumes all volume measurements are made at the same temperature and pressure.