A student generated oxygen gas by decomposing hydrogen peroxide (H2O2) according to the following equation: 2H2O2(aq) -> 2H2O(l) + O2(g)
If the student started with 1.75 moles of hydrogen peroxide, how many moles of oxygen gas would be produced? Show your work.
((If you can just tell me how to do a problem like this I would be eternally grateful.))
You can convert mols of one material in the equation to any other material in your equation by simply using the coefficients in the balanced equation. It works every time. Follow this.
You have 1.75 mols H2O2. How many mols O2 will it give? That's
1.75 mols H2O2 x (1 mol O2/2 mols H2O2) = 1.75 x 1/2 = ? How do you know which number goes on top and which on bottom. Easy. Note that you are converting units; note mols H2O2 on the left cancels with the mols H2O2 in the denominator of the fraction and that leaves you with units of mols O2 which just happens to be what you want. Or if you don't want to do that every time think about it this way. mols of what you started with (in this case mols H2O2) the coefficient of that numbers goes on the bottom. The coefficient of what you want in the answer goes on the top.
Easy to do. Right?
Can someone work this out so I can understand it better?
1.75moles×(1mole02/2molesH2O2=1.75×0.5
To determine the number of moles of oxygen gas produced in this reaction, we need to use stoichiometry - the relationship between the moles of reactants and products in a chemical equation.
In this case, the balanced equation tells us that 2 moles of hydrogen peroxide (H2O2) react to produce 1 mole of oxygen gas (O2).
Given that the student started with 1.75 moles of H2O2, we can set up a proportion using the stoichiometric ratio from the balanced equation:
(1.75 moles H2O2 / 2 moles H2O2) = (x moles O2 / 1 mole O2)
To solve for x, the number of moles of O2, we can cross multiply:
2 moles H2O2 * x moles O2 = 1.75 moles H2O2 * 1 mole O2
Simplifying the equation gives us:
2x = 1.75
Now, divide both sides of the equation by 2:
x = 1.75 / 2
x = 0.875
Therefore, 0.875 moles of oxygen gas would be produced when the student starts with 1.75 moles of hydrogen peroxide.