How much HNO3 can be made from 25.0g of NO2?
Do you know the equation? Here is a worked example of a stoichiometry problem.
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To determine how much HNO3 can be made from 25.0g of NO2, we need to use stoichiometry, which is the relationship between the amounts of reactants and products in a chemical reaction.
Step 1: Write and balance the chemical equation.
The balanced chemical equation for the reaction between NO2 and H2O to form HNO3 is:
3NO2 + H2O -> 2HNO3
This equation tells us that 3 moles of NO2 react with 1 mole of H2O to produce 2 moles of HNO3.
Step 2: Calculate the molar mass of NO2.
Nitrogen has an atomic mass of approximately 14.01 g/mol, and oxygen has an atomic mass of approximately 16.00 g/mol. Since NO2 has one nitrogen atom and two oxygen atoms, its molar mass can be calculated as follows:
Molar mass(NO2) = (1 * molar mass(N)) + (2 * molar mass(O))
= (1 * 14.01 g/mol) + (2 * 16.00 g/mol)
= 14.01 g/mol + 32.00 g/mol
= 46.01 g/mol
Step 3: Convert the given mass of NO2 to moles.
To convert the mass of NO2 to moles, we use the formula:
Moles = Mass / Molar mass
Moles(NO2) = Mass(NO2) / Molar mass(NO2)
= 25.0 g / 46.01 g/mol
≈ 0.543 mol
Step 4: Use stoichiometry to calculate the moles of HNO3.
From the balanced equation, we know that 3 moles of NO2 react to form 2 moles of HNO3. Therefore, the moles of HNO3 can be calculated using the ratio:
Moles(HNO3) = (Moles(NO2) / 3) * 2
= (0.543 mol / 3) * 2
≈ 0.362 mol
Step 5: Convert moles of HNO3 to grams.
To convert moles of HNO3 to grams, we use the formula:
Mass = Moles × Molar mass
Mass(HNO3) = Moles(HNO3) * Molar mass(HNO3)
= 0.362 mol * (1 * 1.01 g/mol + (3 * 16.00 g/mol))
= 0.362 mol * (1.01 g/mol + 48.00 g/mol)
≈ 0.362 mol * 49.01 g/mol
≈ 17.72 g
Therefore, approximately 17.72 grams of HNO3 can be made from 25.0 grams of NO2.