Question

Calculate the mass percent of 0.485 g of hydrogen, which reacts with oxygen to form 2.32 g of H2O.

a) 4.6%
b) 9.4%
c) 13.5%
d) 17.2%

Answer 1

To calculate the mass percent of hydrogen in the given reaction, follow these steps: 1) Calculate the molar mass of H2O. 2) Calculate the moles of H2O formed. 3) Calculate the mass of hydrogen in the reaction. 4) Calculate the mass percent of hydrogen.

Step-by-step explanation:

To calculate the mass percent of hydrogen in the given reaction, we need to determine the mass of hydrogen and divide it by the total mass of the compound formed:

1. Calculate the molar mass of H2O by adding the molar masses of hydrogen and oxygen: 2(1.008 g/mol) + 1(16.00 g/mol) = 18.02 g/mol.
2. Calculate the number of moles of H2O formed using the given mass of H2O: 2.32 g / 18.02 g/mol = 0.128 mol.
3. Calculate the mass of hydrogen in the reaction by multiplying the moles of H2O by the molar mass of hydrogen: 0.128 mol * 2(1.008 g/mol) = 0.258 g.
4. Calculate the mass percent of hydrogen by dividing the mass of hydrogen by the total mass of the compound and multiplying by 100%: (0.258 g / 2.32 g) * 100% = 11.1% (approximately).