What mass(g) of hydrogen gas is produced by decomposing 179.1 g of water. Round your answer to one decimal place.
2 H2O(s) --> 2 H2(g) + O2 (g)
To find the mass of hydrogen gas produced by decomposing water, you need to use the molar ratio between water and hydrogen gas from the balanced chemical equation.
The balanced equation tells us that 2 moles of water (H2O) decompose to form 2 moles of hydrogen gas (H2).
1. Convert the given mass of water (H2O) to moles using the molar mass of water. The molar mass of water (H2O) is 18.015 g/mol (2 hydrogen atoms with a molar mass of 1.008 g/mol, and one oxygen atom with a molar mass of 16.00 g/mol).
Moles of water (H2O) = Mass of water (H2O) / Molar mass of water (H2O)
= 179.1 g / 18.015 g/mol
≈ 9.940 moles of water (H2O)
2. Since the molar ratio between water (H2O) and hydrogen gas (H2) is 2:2, we know that 2 moles of water (H2O) decomposes to form 2 moles of hydrogen gas (H2).
3. Calculate the mass of hydrogen gas (H2) produced by multiplying the number of moles of hydrogen gas (H2) by the molar mass of hydrogen gas (H2). The molar mass of hydrogen gas (H2) is 2.016 g/mol (2 hydrogen atoms with a molar mass of 1.008 g/mol).
Mass of hydrogen gas (H2) = Moles of hydrogen gas (H2) x Molar mass of hydrogen gas (H2)
= 9.940 moles x 2.016 g/mol
≈ 20.04 g
Therefore, approximately 20.0 g of hydrogen gas is produced by decomposing 179.1 g of water.