2H202-> 2H2O + O2
Suppose you carry out the decomposition using 25.0 mL of a 2.00M hydrogen peroxide solution and obtain the following: 8.62 mL of gas is collected in 120 seconds. How many moles of oxygen are produced per second?
well, at STP, 1 mole is 22.4L, so
8.62mL = 8.62/22400 moles
1/3 of that is O2, no?
No temperature is listed in the problem but usually this is at room T; therefore, the only gas is O2.
To calculate the number of moles of oxygen produced per second, we first need to determine the number of moles of oxygen produced in 120 seconds.
From the balanced chemical equation, we know that the stoichiometric ratio between hydrogen peroxide and oxygen is 2:1. This means that for every 2 moles of hydrogen peroxide decomposed, 1 mole of oxygen is produced.
Given that 2H2O2 → 2H2O + O2, we can conclude that 1 mole of oxygen is produced for every 2 moles of hydrogen peroxide decomposed.
Now, let's calculate the number of moles of oxygen produced:
1) Calculate the number of moles of hydrogen peroxide used:
To find the number of moles of hydrogen peroxide used, we use the formula:
moles = concentration × volume
moles = 2.00 M × 0.0250 L (since we have 25.0 mL of a 2.00M hydrogen peroxide solution)
moles = 0.0500 mol
2) Calculate the number of moles of oxygen produced:
Since the stoichiometric ratio between hydrogen peroxide and oxygen is 2:1, we divide the number of moles of hydrogen peroxide used by 2 to get the number of moles of oxygen produced:
moles of oxygen = 0.0500 mol ÷ 2
moles of oxygen = 0.0250 mol
Now, we need to determine the number of moles of oxygen produced per second. We can use the collected volume of gas and the given time to calculate the rate of oxygen production.
3) Calculate the volume of oxygen produced per second:
To find the volume of oxygen produced per second, we divide the collected volume of gas by the given time:
volume of oxygen per second = 8.62 mL ÷ 120 s
volume of oxygen per second = 0.0718 mL/s
Note: The volume should be converted to liters to match the units of the concentration.
volume of oxygen per second = 0.0718 mL/s × (1 L/1000 mL)
volume of oxygen per second = 7.18 × 10^(-5) L/s
Finally, we can calculate the number of moles of oxygen produced per second by multiplying the volume of oxygen produced per second by the concentration of the original solution:
moles of oxygen per second = volume of oxygen per second × concentration
moles of oxygen per second = 7.18 × 10^(-5) L/s × 2.00 M
moles of oxygen per second = 1.44 × 10^(-4) mol/s
Therefore, 1.44 × 10^(-4) moles of oxygen are produced per second.