if you burn 20.2g of hydrogen and produce 1.80x10^2g of water, how much oxygen reacted?
2H2 + O2 ==> 2H2O
mols H2 = grams/molar mass
Using the coefficients in the balanced equation to convert mols H2 to mols O2.
Now convert mols O2 to what you meant by "how much". If you want grams O2, g O2 = mols O2 x molar mass O2.
If you want volume at STP it is L = mols O2 x 22.4 L/mol = ?
To find out how much oxygen reacted, we can use the principle of conservation of mass.
The balanced chemical equation for the reaction between hydrogen and oxygen to form water is:
2H₂ + O₂ → 2H₂O
From the equation, we can see that for every 2 moles of hydrogen reacted, 1 mole of oxygen reacts. Therefore, the molar ratio of hydrogen to oxygen is 2:1.
Step 1: Convert the given masses of hydrogen and water into moles.
Molar mass of hydrogen (H₂) = 2 g/mol
Molar mass of water (H₂O) = 18 g/mol
Number of moles of hydrogen = Mass of hydrogen / Molar mass of hydrogen
= 20.2 g / 2 g/mol
= 10.1 mol
Number of moles of water = Mass of water / Molar mass of water
= 1.80 x 10^2 g / 18 g/mol
= 10 mol
Step 2: Determine the limiting reactant.
Since the molar ratio of hydrogen to oxygen is 2:1, we can see that we have 10.1 moles of hydrogen. This means we require half of that amount in moles for oxygen, which is 5.05 moles.
Comparing this with the actual amount of oxygen reacted will determine the limiting reactant.
Step 3: Calculate the amount of oxygen reacted.
The number of moles of oxygen reacted is equal to the number of moles of oxygen required (determined in step 2) minus the number of moles of oxygen formed.
Number of moles of oxygen reacted = 5.05 mol - 10 mol
= -4.95 mol
Since the stoichiometry of the reaction cannot have a negative number of moles, we conclude that all of the oxygen in the reaction has reacted. Therefore, the amount of oxygen reacted is 10 mol.
Step 4: Convert the number of moles of oxygen reacted into grams.
Mass of oxygen reacted = Number of moles of oxygen reacted × Molar mass of oxygen
= 10 mol × 32 g/mol
= 320 g
Therefore, the amount of oxygen that reacted is 320 grams.
To determine the amount of oxygen that reacted, we need to consider the balanced chemical equation for the combustion of hydrogen:
2H₂ + O₂ → 2H₂O
From the equation, we can see that the mole ratio between hydrogen and oxygen is 2:1, which means that for every 2 moles of hydrogen, we need 1 mole of oxygen.
To find the number of moles of hydrogen, we divide the given mass (20.2g) by the molar mass of hydrogen (2.02 g/mol):
moles of hydrogen = 20.2g / 2.02 g/mol = 10 mol
Since the mole ratio is 2:1, we have 10 moles of hydrogen reacting with 5 moles of oxygen.
To find the mass of oxygen, we multiply the moles of oxygen by its molar mass (32.00 g/mol):
mass of oxygen = 5 mol * 32.00 g/mol = 160 g
Therefore, 160 grams of oxygen reacted in the combustion of 20.2 grams of hydrogen.